Engine top end
From:
"Graham Stretch" < technical_at_iwnet.screaming.net >
Only
one product for this job IMHO, that is Wellseal, it is a runny version of what
is already on original gaskets, (Shellac, a type of varnish I believe?) This
was recommended by Fred, the local machinist, and a very knowledgeable man.
From:
Hugh Fader < hfader_at_usa.net >
I used
Permatex copper tack spray. No problems since assembling it last May.
> Still trying
to decide how much to mill the head, but will probably be conservative and go
for about 9:1.
If running on 87
octane gas is important to you then stop there. But if you are willing to go
with premium then you can probably go all the way to 10:1. I had mine shaved to
about 9.5:1 and I have no trouble running on mid-grade.
The dead blow mallet
probably won't hurt, but IMO won't help either. I've also had trouble with the
edge of the block crumbling away, if I pried between the head and block too
enthusiastically. One technique that seemed to work fairly well for me was to
make up a plate with bolts that thread into the rocker cover stud holes, and
then pry between the plate and the top of the cylinder studs. Soaking things in
PB Blaster (or your favorite penetrating oil) may help too, as sometimes water
gets into the area between the studs and head, causing all sorts of corrosion.
Another that I've
heard of is to pack #1 and #4 (or #2 and #5 for a 6 banger) with rope through
the spark plug holes, and then use the starter to turn the engine over. The
rope is soft enough to not hurt anything.
You may have to repeat this several times, turning the engine backwards
by hand each time, and perhaps adding more rope as the head starts to come free
You can also try
removing the studs first, which makes it much easier to get the head off .
Randall
I bought my TR3, 1960
TS 78563 about 16 years ago, and rebuilt the engine. During the rebuild I found
the head casting to be cracked, so I bought a replacement, The cracked one has
the slanted bottom to the thermostat housing, (2nd phase high port). The
replacement head, has the rounded bottom thermostat housing (1st phase high
port).
Question #1, Is the 2nd phase high port head a lot better
than the 1st phase high port head.? and why?
The phase 2 high port head
is supposed to have more metal between the bottom of the head and the water
jacket and thus be more resistant to cracking and more forgiving when shaving
metal off the head.
Of course if the
bypass is blocked off so water is not allowed to flow through the head while
the thermostat is closed all bets about head survivability are off.
Note: I also
installed 86 mm sleeves and pistons during the rebuild. I read where they used
the 3rd phase high port head with the 86 mm sleeves and pistons Thus,
They added a camphor
along the side of the combustion chamber to increase squish head volume and
keep the compression down to 9:1
Question #2, Is the
use of the 1st phase low port head with the 86 mm pistons a problem and what
does this do to compression ratio?
It will raise the
compression ratio and the engine will probably go like stink.
Question #4, Any lead additives out there that work,? and
do I mix both, lead and octane boost?
It seems to take
forever for unleaded to cause real damage. I'm not sure if a lead
additive really helps.
From Randall
It's not for the faint
of heart, nor for those using stock head gaskets. Get a copy of the Kas
Kastner TR3 or TR4 competition preparation manual. The combustion chamber mods
are discussed in there, with drawings. ( Download
this manual ,pdf, 13MB). In short, the intake valves are pretty big for the
bore on a TRactor engine, the edge of the valve is very close to the edge of
the bore, so the head has a 'pocket' around the intake valve to improve
breathing. The modification consists of extending that pocket down into the top
edge of the liner, to improve breathing further, and to eliminate the knife
edge left by milling the head; plus cutting away part of the 'quench' area to
reduce turbulence after milling. Note that the "shim steel" head
gaskets mentioned in the Comp Prep manual are available through BFE, TSI,
Racetorations, etc. Ken Gillanders at told that they could not get the solid
copper gaskets to seal reliably, so they found a manufacturer willing to
reproduce the steel ones. Copper equivalents are available. One highly
recommended source is http://www.headgasket.com/
I believe Moss also carries them, I know BFE does.
From: "Jack W. Drews"
vinttr4_at_geneseo.net
TR4 heads can develop oil leaks at the pushrod tubes
because of damage, aggressive cleaning, and milling, which remove some of the
swaged area at the head face.
There are a couple of things you can do if the leak
is mild.
To seal the bottom ends, clean all the paint you can
off of the joint between the tubes and the head and apply a very small bead of
J. B. Weld around each tube. Obviously this works best on a head that has not
yet been painted, but you can at least slow down the leaks this way. It's hard
to get at the backside but you can get at most of the circumference.
For the upper end, epoxy inside the valve cover
usually doesn't stay put. However, there is a green Loctite compound available
which is made to creep into assembled joints. Clean the upper ends off as well
as possible with lacquer thinner or Loctite primer -- the cleaner the joint,
the more likely it is to work. Then put a little bead around the top of each
tube where you see the tube ends inside the valve cover. I'd leave all this at
least overnight before getting oil on it again.
If tubes are badly damaged and must be replaced, this
can be done by driving out the old tubes, reaming to a couple thousandths
smaller than .750 (run the reamer at low rpm!), cutting aluminum tubes to
length and pressing in. The aluminum tubing is the standard .750 diameter
available in hardware stores. It should be parted off with a lathe and not cut
with a hacksaw, in order to make the ends exactly square. When reaming, set the
head down on the drill press table and ream until the end of the reamer just
kisses the table -- do not ream all the way through. This leaves a small
reverse chamfer at the bottom. Then press or drive the tubes into the holes,
and use red Loctite. The final operation is to swage the top end with a tapered
tool.
From: "Mike
Kitchener" mikek_at_wanadoo.fr: The castings are done by Grainger &
Worral . They also do castings for British- American Racing F 1 team.
From:
wallaces_at_superaje.com
When I ordered guides
from Ken Gillanders at BFE for my 3a head, he specifically told me not to use
seals. As some of you know, Ken has extensive experience racing these cars, so
this advice may apply most to extreme conditions, but, good to know. He also
said that when the guides are reamed, they should have more clearance than is
found on modern engines. The reason for this is that there is a lot of mass around
the guides, and when the head gets hot the heat is not dissipated as well as on
modern heads. The bores of the guides thus shrinks more than we are used to
nowadays.
From: Randall Young
randallyoung_at_earthlink.net
I've heard the same
thing, specifically about the TR2-6 motors.
I've also been told that lubrication is even more important for the
aftermarket silicon-bronze valve guides than for the stock cast-iron ones, as
the bronze is more apt to gall to the valve stem with insufficient
lubrication. Seals, especially the
'teflon' type, are only for race motors, where oil control is more important
than long life.
However, I was able to
find teflon type seals that fit my early TR3 'LeMans' head with no
modifications, at the local speed shop.
I just took them the stem diameter and the guide diameter, they gave me
a handful of seals. Note that I still don't recommend seals, this was an
unusual case.
From: Randall Young
<ryoung_at_NAVCOMTECH.COM
Going much larger than
stock is very problematic on the TR4 head, the valve stem centers just don't
allow room between the valve heads. BFE does sell slightly oversized intake
valves to compensate for seat wear, and I believe they recommend replacing the
exhaust valve seats when they become worn.
From: "Jack W.
Drews" vinttr4_at_geneseo.net
I have oversize valves
in my TR4 head -- both intake and exhaust. It looks like it would be a problem
putting them in but it is not. They are superior quality stainless steel and
with a high-flow shape. They are also more expensive than stock valves from the
big 3, coming in at about $30 apiece. Standard valves are about $20 apiece.
However, if your valves have been ground three times, your seats may be
pocketed too low, requiring hard seats on exhaust or intake or both to correct
the problem, in which case putting in larger valves is less expensive than hard
seats and valves.
British Frame and
Engine has them. Call Ken Gillanders at 626-443-0939. I don't know of a low
price substitute, but there may be one unknown to me.
Installing (TR3 and
TR4)
Randall
ryoung_at_navcomtech.com
I've had a fair amount
of trouble with TR3 head gaskets over the years, but I've never been able to
tell that which way it was installed, or what goop I put on it, made any
difference.
IMO the important part
is to be sure that your liners stand out of the block by the specified amount
ON BOTH SIDES, preferably near the .0055" maximum (or maybe even a little
more). I discovered that for some
reason, possibly the block not being machined square, the liners on my current
engine measure .004" on one side, but only .002" on the other.
The correct solution
would be to have the block machined ("decked"), but since I didn't
want to pull the front apron, I soldered copper wire to the head gasket
instead. Seems to've worked <knock,
knock>
On my previous engine,
the liners stuck out by about .005" on both sides, and the gasket would
seal even if reused once or twice.
I do note that Mordy
Dunst (Gasket Works USA LLC) has a specific sealer that he recommends (and
sells) for use with his solid copper head gaskets (which are apparently
somewhat difficult to keep sealed on racing motors). That was going to be my next step, if the wire didn't work.
Mordy's website is http://www.headgasket.com
BTW, my head gasket
leaks always showed up as cooling problems.
The combustion gases would leak past the gasket into the water jacket,
forcing water out the overflow and leading to overheating.
Leaking Head Gasket
From: "Ryan_at_Ledwith" ryan_at_ledwith.com
I found some coolant leaking from my recently assembled engine at the head
gasket. After a few hours I checked it again and found coolant leaking out of
the spark plug holes for the #2,3,and 4 cylinders. Not #1. I never attempted to start the engine.
I pulled the head and checked the head gasket and found that it was
Sealed pretty well to the head and the block. For those interested, I took
pictures: www.ledwith.com/healey . I checked the flatness
of the head using a piece of glass and found it to be flat. The block and the
head had been surfaced during the rebuild. The only thing to check next is the
block.
No conclusions yet. The amount of leakage was too great to be from
simply a poorly fitted gasket or an improperly torqued head, yet I didn't find
any thing that would have caused the head not to seat properly. The head bolts
were sealed into the block before assembly, and the bolts didn't seem to pull
up on the block, causing a lip around the bolts. I reused the original head
bolts and nuts and washers. Some people suggested this could cause problems,
others said they've used old bolts without problems. I can't see how old bolts
would have contributed to the leakage. At this point, all I can figure is that
the gasket must have not seated properly and jammed up. The only course of
action I am thinking of is to use another head gasket and try again.
From: Bill Lawrence : "ynotink" ynotink_at_qwest.net
You can have trouble with a head gasket if you tighten the bolts in the wrong
sequence or if the head is somehow cocked when it is placed on the gasket. I
had that experience a few years back on a TR-6. All you can do is replace the
gasket and try again.
From: "Wm. Severin Thompson" wsthompson_at_thicko.com
Roger Menadue related a story to me about a Nash engineer having
repeated difficulty with a head gasket on one of the race cars. Roger finally
pulled the head down (Roger never used a torque wrench in his life... he relied
on "feel") and the head gasket problems disappeared.
Torque wrenches can be wildly inaccurate, depending on a number of
factors. If they're dropped, or left in a position at anything over 0.0 lbs, or
for that matter, just a cheap torque wrench, can cause you problems. Also,
another factor, is the lubricant used as you torque the head. I had repeated
problems with one of my race motors (using ARP studs). There were two different
torque specs, depending whether you used oil, or a moly-based lubricant. You
might try a different, recently calibrated wrench,. and a molybdenum-based
lube, and that might solve your issues.
> I see that TRF has a sale on external oilers for a TR3
valve train. What's the conventional wisdom on these oilers. Do they help? Is
it worth it? I
Bill, I tried one and hated it. It dramatically increased the amount of
oil sucked past the intake valve stems, and lowered overall oil pressure
(especially at hot idle). The stock oil passages to the rockers do have a
tendency to get clogged, especially if you don't change the oil often
enough. High paraffin
("Pennsylvania grade") oil may aggravate the problem too. But IMO this cure is worse than the disease. Better to just check the rocker oiling
occasionally (let the engine idle for a minute with the rocker cover off, look
for oil seepage from the front rocker), and clean the oil passages if
necessary.
Randall
Below is a interesting
thread we had on the Healey list regarding the pros and cons of bronze guides.
My conclusion: stick with steel…
From: Blue One Hundred
international_investor_at_yahoo.com
Manganese-bronze
guides are superior to the original style ones... they lubricate better and
wear out less.
From: "Michael
Salter" magicare_at_rogers.com (edited)
After a considerable
amount of research on the subject after encountering problems with Chrysler 3.0
V6 and MGB engines fitted with bronze guides, a machine shop owner send me a
letter describing all the problems they had encountered on various types on
engines with bronze guides in iron heads. I would strongly recommend cast iron
guides only.
IMHO bronze guides in
any multi carb engine is a recipe for disaster as it is not too hard to get a
lean mixture, hence seriously elevated combustion temperatures, in 2 or 3
cylinders while the engine will still run fairly well.
Cast iron has worked
well for many, many years and I can't think if any manufacture who installs
bronze as standard equipment.(Could stand corrected there). I bet they have a better reason than just
cost.
Exerpts of the letter:
“Upon detailed inspection and measurement
we find the valve stem diameter of the valve remains stable but the inside
diameter of the valve guide becomes smaller. Only the area of the valve guide
which is encapsulated in the cylinder head casting has realized a reduction of
the inside diameter, while the upper portion of the valve guide which protrudes
above the casting in the valve spring area is unaffected. Measurements of the
valve guide inside diameter at the upper area above the casting confirms proper
clearance while measurement taken along the entire encapsulated length of the
inside diameter of the valve guide area realizes substantial reductions in
clearance.
In virtually all cases the exhaust valves are
the only valves affected by this phenomena with a higher degree of seizures
occurring at exhaust valves residing in or close to heat cross over ports. We
have witnessed no spalling, galling or transfer of metals from the valve to the
valve guide or vise versa. It is our belief that the fuel additives enhanced by
increased combustion temperatures may allow certain lubricants to oxidize
therefore coating the inside diameter of the valve guides with a hard varnish
type residue which slowly reduces clearance and ultimately creates valve
seizure in supplement to the inside diameter of the guides to collapse because
the guides are expanding at a greater rate than the head casting. “
From: "Mr. Finespanner"
MrFinespanner_at_prodigy.net
As Mike demonstrated with Aldo's letter, do NOT use manganese-bronze valve guides! If you must have bronze, use silicone-bronze. The manganese can constrict in
the ID with use, resulting in seized valves and other problems. One of Aldo's
guides seized so hard in my engine that the pushrod actually broke. You are better off with regular steel
guides.
From: "Jack W. Drews" vinttr4_at_geneseo.net
About three years ago there were several Triumph engine failures in racing
engines because valves froze in valve guides. For some unknown reason, more
than one machine shop made the same mistake at the same time -- they did not
ream the bronze valve guides to the proper clearance. All the theory is good,
but this is what happens if the bronze guides have less than .002 to .003 clearance.
Virtually everybody racing these engines uses these guides. Interestingly to
me, an engine I'm working on at the minute has them -- and the guides are too
tight in the center, where they are contained by the cast iron, but loose
enough on the ends where they stick out...
Date: Thu, 07 Feb 2002 00:06:50 GMT
From: mporter_at_zianet.com
> … I stopped at a machine shop that was highly recommended to me. The owner
told me that he did not recommend bronze guides. Said that cast iron was harder
and would last longer under normal road use. This is not what I thought. Any
opinions?
As for hardness, it depends upon the process used to make the guide. But,
hardness is not the only quality necessary for a valve guide. If it were, they
could be made from anything hard. In fact, the phosphor bronze and manganese
bronze used in valve guides today is about as hard as cast iron, is tougher
(anyone who's tried to knurl a cast-iron guide knows this), and has better
natural lubricity. Natural lubricity is important--that's why one can run a
bronze guide with a valve stem seal, but an iron guide, with iron-iron contact,
has to have a fair amount oil going past the guide. And, regarding wear, it's
more or less impossible to refurbish a cast-iron valve guide by knurling. They
chip, rather than deform, during knurling, while a bronze guide has just enough
malleability to deform sufficiently to be knurled and reamed to size, so it can
be re-used at least once. Look at it this way. Manufacturers today have to meet
much more stringent emissions than when Triumph engines were being built, and
that means they can't have oil going down the guides. And, some manufacturers,
such as Ford, are now warranting some engines for 100,000 miles. What sort of
guides are they using in such engines? Not cast iron. <smile> If
cast-iron were a superior material for valve guide use, they probably would be
using it. Cast iron guides were suitable and cheap when these engines were
being made, but there are better materials in use today.
From: alan_at_andysnet.net
Try Marvel Mystery Oil. Can you tell which
valve is sticking? If not, squirt Marvel Mystery Oil into all cylinders. This
oil is really great for sticky valves.
http://www.headgasket.com/gaskets.html
When using copper gaskets in any motor ask
the machine shop to get an RA (roughness average in Microinches) of about 60
for cast iron heads and blocks and closer to 40 for aluminum.
From: Blue One Hundred
<international_investor_at_yahoo.com
Stellite faced valves are harder &
longer lasting than the original exhaust valves. They will last longer. I have them in my BJ8 and haven't chipped a
valve in 70K miles.
There are four schools of thought on what
you should do with the head, which is the following:
·
Use lead
substitute. I use Bardahl's instead
o'lead gold. Great product includes
octane boost that actually works. This
costs more money over the long run, but the results are excellent.
·
Use unleaded
with no substitutes. Some people say
that lead is unnecessary to protect your head, although I think most of the
people doing this are running motors that used to run leaded, thus have a build
up of lead on the valve seats.
·
Harden the
head's valve ports/seats. You can have
this done at some specialty machine shops - it should be done by a pro with
experience on British engines. This will prevent head wear in the absence of
lead.
·
Insert the
figure eight valve seats that some of the racers use. This is recommended by a
few suppliers in England, and I think the results are probably excellent... but
it's a little costly. These special
seats should be installed by a pro.
1:1.45 stock
1:1.6 racing (with rollers)
My
suggestion at this point would be to first recheck your valve clearances.
One good method is to turn the engine by hand until the next cylinder (doesn't
matter where you start) reaches the "point of balance" your book
talks about, where the intake valve is just
opening and the exhaust valve is just closing (don't have to be exact here,
just reasonably close); then check the clearances on the cylinder that is
'opposite' in the firing order. For example :
Turn
#1
to balance, set #4
#3
to balance, set #2
#4
to balance, set #1
#2
to balance, set #3
Now,
turn the engine so #4 is "on balance", and check the position of the
TDC mark. If it's pretty close (within 1/2" or so), you can assume
it's accurate, otherwise the pulley is assembled wrong.
From: Michael Salter
<magicare_at_home.com>
Apply the rule of 13 .........
#1 open
Adjust #12
#2 open
Adjust #11
#3 open
Adjust #10 etc....etc....etc...
For 4 cylinders (normally) The rule of 9
All of the Healey heads are of the same
general design, yet some of the valve covers said "Hot" and some said
"Cold". For a while I figured that in the interest of my fingertip's
health, I would "adjust" for Hot (thinking that the pushrod elongated
and the valve stems elongated, etc) and adjust the valves Cold. But then some
wise engineer told me that the elements of the valve train elongated with heat
to self-cancelling changes at the rocker/valve stem intersect - so I thereafter
adjusted them Cold
From: STEVEN.SCHMIDT_at_Inrange.com
Porting and polishing is primarily used to
increase the volume of the intake and exhaust runners within the head. If you
were to look at a cross section of an intake runner you would see that the
runner is wide at the inlet and continually narrows as it gets closer to the
combustion chamber. Porting generally removes
some material from the "roof" and "floor" of the
inlet and as much material as possible from the valve "pocket"
without breaking through to the water jacket. A secondary effect of porting is
that it reduces the severity of the angle the fuel air mixture has to negotiate
when heading towards the combustion chamber.
When moving air meets an obstruction, it becomes turbulent. Turbulent
air picks up more heat than air that is not turbulent. Porting reduces turbulence, lowering the
fuel/air mixture temp entering the combustion chamber which increases
horsepower. Some argue that a certain amount of turbulence is good because it
causes the fuel air mixture to "swirl" into the combustion chamber.
I've used the intake as an example, but
the same principles apply to exhaust ports. Manifolds can also be "port
matched". Port matching can increase horsepower. If the intake manifold
has a larger opening than the head,
part of air fuel mixture "slams" against the face of the head when
exiting the manifold causing turbulence.
Conversely, if the exhaust manifold has a
smaller opening than the head, exhaust gasses "slam" into the face of
the manifold casing turbulence and increasing back pressure.
Porting and polishing, if not done
correctly, can ruin an engine. Determining how much material to remove takes
experience and know-how. Removing the material takes talent. I would not
recommend to anyone that they try to port their Healey head without plenty of
previous experience. I would only allow
someone experienced with Healeys to do this for me.
http://www.webcamshafts.com/cam_glossary.html
From: Randall Young
ryoung_at_NAVCOMTECH.COM
TR6 maybe not valid for TR3/4. to be checked
It should also be possible to make ½ tooth
and 1/4 tooth adjustments in cam timing.
The factory cam gear has 4 holes in it, but only 2 are used at a time.
If I remember correctly, using the other pair of holes results in a 1/2 tooth
difference, while flipping the gear front to back causes a 1/4 tooth
difference; but I could have that backwards.
I've also heard that some aftermarket
gears are not cut properly, so this doesn't work.
From: "Randall Young"
ryoung_at_navcomtech.com
It runs, but only with a very rich
mixture, and won't idle less than 1500 RPM. Starting is difficult. When hot and
turned off the engine keeps dieseling (probably because it's too rich - the
SU's are at 4 full turns)Could the timing chain have slipped a cog? Looking at
the manual, and spinning the crank to see when the valves open/close it appears
to be off (it's late), but not by much. Can this symptom be caused by timing
error? I'd hate to open up the front end of the engine just to find out it's
just fine.
I believe it's a definite
possibility. I once helped a friend who
had assembled a motorcycle motor (which was a 4-stroke) with the timing chain
off by one tooth, and it would consistently foul plugs in just a few minutes of
running.
However, it's not hard to check cam timing
(with the stock cam) with just the rocker cover removed. If you trust your TDC mark, it's even
easier. Assuming the TDC mark is good :
First turn the engine until #4 exhaust is
just closing, and the crank is at TDC. Set the valve lash for #1 intake and
exhaust to .050". You can stack
multiple feeler gages together for this. It doesn't matter if the value is not
exactly .050", as long as they are the same. Now turn the crank forward
one full turn, coming back to TDC and stopping. You have to stop on the mark, you cannot turn the crank backwards
(or the reading will be inaccurate). Now measure the lash on #1 intake and
exhaust (without moving the crank). If they are equal, then the cam is
perfectly timed. If the intake is
tighter than the exhaust, the cam is retarded.
When you are done, turn back to TDC with
#4 intake closing, and reset the #1 valves to .010".
Date: Thu, 05 Sep 2002 09:00:02 -0500
From: "Jack W. Drews"
vinttr4_at_geneseo.net
As many of you know, I race a TR4 in
vintage races and I prepare engines for others. I have just been made aware
that the tappetts (cam followers) being sold by Moss and TRF at the moment are
SOFT.BEWARE! Soft lifters will destroy your camshaft and maybe your engine.
Yesterday a friend from Texas had lifters
from Moss and TRF checked for hardness and found them all dead soft. A couple
of months ago I ordered lifters and three of the eight were improperly machined
-- bored too deep. I have not been able to get Moss's attention on this
Where to get good lifters? Ken Gillanders
of British Frame and Engine, Greg Solow of Engine Room. Maybe others I don't
know about.
From: "Gerald Van Vlack" jerryvv_at_alltel.net
Check out this web site,
he provides cams and he can recondition your present set of lifters.
He seems to know the
needed technology of matching the correct hardness with cams etc. His prices
seem very reasonable as well. NFI and have never used him but will when the
time comes.
From: Dean Caccavo healeybn7_at_yahoo.com
Well it looks like my pushrod issues are
finally behind me. If you recall the
replacement pushrods I received from AHSpares and then from Moss were too large
on the lifter end and too small on the rocker end to allow the adjusting ball
or lifter cup to properly seat. The
result was that the pushrods were beating themselves into place and causing my
valve clearances to open up over time.
Last week I installed a new set of
pushrods from Isky (http://www.iskycams.com/index.html). These look like quality parts with
properly machined ends and hollow chromoly(sp) tubes. They must be 30% lighter and were 40% less expensive then Moss.
What a difference from the Moss/AHSpares forged pushrods. To Moss's credit they
pulled their supply of pushrods and lifters from inventory until they complete
their analysis.
From: Editorgary_at_aol.com
>>Also, can a regular cam be ground
to road rally specs? Those ones for
sale are a bit pricey, at 312 lbs sterling. Which ones have people had
experience with (cape-international has several to choose from).
If you're only interested in street use,
my experience is that the cam specs from the Phase II BJ8 are perfectly all
right, and I'd recommend them for every rebuilt engine from the very first
2912cc engine used in the 59 BN7s and BT7s.
He states that the fan extension acts as a
harmonic balancer. I've never heard that, and had removed mine last year when I
installed an electric fan.
I don't believe it's the extension itself,
but rather the fan and the rubber bushings it rides on. Not a 'balancer', but a 'dampener'. Ken G. has written of this for the local
club newsletter.
I was planning on installing the harmonic
damper kit from BFE, but Ken G. basically said don't bother except for
racing. Am I risking anything by
leaving the extension off?
The risk is a broken crank. I honestly
don't know how big a risk it is, but it appears that if you never exceed 5000
rpm, the risk is minor. I don't have
either on my TR3A, and it has exceeded 5000 rpm on many occasions without ever
breaking a crank. But my next engine
will have a dampener.
From: "Edward Woods"
fogbro1_at_attbi.com
My '3's crank broke late one Sunday night
…Have a crank downstairs that I had intended to use. Shop found a crack when it
was magnafluxed. Same place, No. 4.
From: "Randall Young"
ryoung_at_navcomtech.com
Most of the local racers apparently use
prepared original cranks (shot-peened, nitrided, balanced, etc.), although some
certainly are running billet cranks. Yes, the originals break occasionally, but
last I heard, a new billet crank was something like $2400 ...
From: "Jack W. Drews"
vinttr4_at_geneseo.net
Broken TR cranks are quite common. All TR
racers are aware of it and broken cranks and rods are what make most of us keep
our rpm's below 6000, which delays the failure. I have my stock crank
magnafluxed every time I have the engine apart and average two or three seasons
before it breaks. I've been lucky so far and have not had one break at speed.
Besides the cranks now being 40 - 50 years
old, there is a designed-in fatigue failure feature. The undercut radius at the
front edge of the rear main journal is where the fatigue failure occurs.
Picture this -- those four cylinders alternatingly snapping the crank both
forward and back, the rear of the crank basically hooked to the ground, and the
crank being subjected both to those
forces and to torsional vibration. Ugh.
Many of us try the shot peening -
nitriding etc approach. This does not necessarily eliminate the problem, as
Henry Frye of Connecticut can attest to, having broken a nitrided crank after
1-1/2 weekends. Of course, Henry's engine was running so well at 6200 - 6700
that he drove it at that rpm. Until the crank broke, of course.
TeriAnn has some good comments saved on
her website at
http://www.cruzers.com/~twakeman/TR/Net_TRcranks.htm
From TeriAnn Wakeman (
twakeman_at_cruzers.com )
The very first thing you should probably
do is check over the crank for cracks and if it is good have it nitrided for
additional strength. Add the harmonic dampener to help tame the big harmonic
just above 5000 RPM. If the harmonic dampener is added & the crank is
nitrided your bottom end will be a lot stronger for the 5000 - 6000 RPM range.
Hopefully you already removed the
combustion chamber shrouding that is around the intake valve & plug.
That's a power biggie.
You should have the TR4A valves for better valve pocket flow. You might
consider going to an oversize exhaust valve since exhaust is normally the
limiting factor to TR3-4 head breathing.
If you have not already, you should
replace a lot of the stock internal engine fasteners with stronger ones. An
Aluminum flywheel and carillo rods will help the engine rev quicker. A reworked
TR6 clutch will work better than the TR3 clutch. But today's clutch
materials available on stock TR clutch disks tends to come apart over 6000
RPM. So a scatter shield could come in handy if you don't have a rev
limiter.
From: Darrell Walker
darrellw_at_inetarena.com
Subject: TR4A semi-performance rebuild
I'm starting to get a picture of what I
intend to do during the rebuild of my engine.
I'm still undecided (or unsure) of a few points, and am interested in
the list's opinion:
Compression ratio: The comp prep manual
suggests 10.2:1 for a street engine.
I'm going with a cam that is a step down from the "D" grind
(270 duration vs. 284, a bit less lift).
Would a C/R around 10 be any problem with today's gas (I would run premium)? Can a C/R be too high for a
given cam? The one I'm going to use says 9:1 minimum, but nothing about
ideal or maximum.
I believe so, unless you also do a fair
amount of combustion chamber work to remove the hot spots (as also outlined in
the comp prep manual). Note that today's premium in the US is about the same
octane as originally called for with the stock C/R ... and it's likely to drop
further. As far as I know, the C/R cannot be too high.
Lightening: The comp prep manual shows where to shed quite a bit of weight
from the rods. I won't be rev'ing over
5000 (not going to install the harmonic damper kit), is lightening the rods
still beneficial? Same question for the
rocker arms.
Might reward you with a little less wear
and valve float at red line, probably won't make much other difference.
Alloy sump: Seems like "everyone" used to carry these, now only
Racetorations & BFE still seem to (for big $$). Anyone know of another source?
I don't.
Chromoly pushrods: I'm probably going to get new pushrods. Are chromoly pushrods stronger or lighter
than stock? Or both?
Stronger.
Ken Gillanders (of BFE) once wrote of looking at stock 5/16"
pushrods with a strobe light, he said they looked like "dancing
spaghetti".
Header:
I'm still undecided on using the stock TR4A manifold or a header. One
issue is the heat. Do the ceramic
coatings really work? I might do that
even on the stock manifold. Does
everyone supply the same headers, or is one better than the others?
There are several different headers
around, with distinctive designs. However the stock 4A 4-2-1 design supposedly
works pretty good on the street, and the best headers for the street supposedly
mimic this design.
From: Darrell Walker
darrellw_at_inetarena.com
I'm installing the Moss aluminium head
onto my TR4A, which comes with the shrouding around the intake valve removed
(as detailed in the Comp Prep manual). The Comp Prep manual also outlines the
procedure to match the cut-away area with the liner, which I would like to do.
After applying grease to the tops of the liners, installing the head, and
removing, I found the following:
- -The thickness of the liner wall where
the removal needs to happen is 0.330" (these are 87.5 (0.060 over) liners)
- -I need to remove 0.180" at the
widest part, leaving 0.150" of the liner. That seems like I'm removing a
lot of the thickness, more that what the picture in the Comp Prep manual seems
to show. Is it too much? I'm using a solid head gasket, so I'm not
losing and sealing rings, but does that leave enough to seal? Will that weaken the liner?
I got some replies off-list, so I thought
I would summarize. The consensus is
that there shouldn't be a problem with removing that much liner, though there
is some feeling that it really doesn't make any performance difference if you
match the liners or not.
From: Doug Hamilton
douglasehamilton_at_shaw.ca
In talking about cooling, he mentions an
aluminum radiator (apparent available in England), and says you should fit one
before giving "any thought to fitting an aluminum cylinder head
The only thought I have on the radiator up
grade to an aluminum one before installing the aluminum head is when you are
running an aluminum head on an iron block it becomes even more important to
keep coolant temperatures in their ideal range if you want your head gaskets to
hold up the same as they would with an iron head. Make sure to check if the
head manufacturer has a recommended head gasket and if they don't find the best
quality gasket you can find some will not last all that long with the aluminum
head iron block combo. I've been lead to believe a teflon coated composition
gasket with o-ring seals in it is the best choice for this combo others may
have differing opinions. Distilled water and an aluminum compatible coolant are
a very important part in maintaining your aluminum head electrolysis will eat
your head very quickly if the wrong coolants are used.
From: "Jack W. Drews" vinttr4_at_geneseo.net
There is a recurring discussion on the
lists regarding installing narrow belts for alternators, providing some sort of
torsional vibration dampener, and the pro's and con's of removing the fan. I
recently offered some parts for sale on eBay that caused a number of questions,
and I thought I'd share what I know about this subject.
There are apparently two commercially
available kits. One is from England (I don't know the vendor) that includes the
crank and water pump pulleys. One is from British Frame and Engine
(626-443-0939) and contains a water pump pulley, a crank pulley with a
torsional vibration damper that was dyno-developed, a fan belt, and a new
timing cover seal to fit the new pulley. Price $380. The only tricky part in
its installation is the need to mark the pulley for timing, because it comes
with no marks. It is the highest quality approach I know of.
The third approach has been around for a
long time and is the subject of this message. It is not quite as good because
it requires a little machining, the damper is not tuned quite as well, and the
Woodruff key in the crank does not engage very far into the pulley.
However, it's pretty cheap. I have had one on my car for six years of racing
and it has caused no problems, but for racing I will eventually switch over to
the BFE kit.
This low-buck approach uses an MGB crank
pulley -- I think there are two models -- but the one you want is 4-5/8"
diameter from the early 3-main MGB (the one from the 5-main engine is 5 1/8”).
The portion that contains the seal surface is the wrong length and diameter, so
the engine side of the pulley must be machined off until the pulley bore is
11/16" deep. Then you take a TR4 pulley and cut off an 11/16" piece
of the engine side of that pulley, creating a spacer that goes on the crank
first and provides a seal surface. So then you put on the new spacer, put on
the altered MGB pulley, and secure with the heaviest washer you can find and a
5/8" fine thread bolt, 1-1/2" long or so, with red Loctite.
After doing this you can't use the fan, of
course, but it doesn't do much anyway, and you must make or buy a water pump
pulley suitable for a narrow belt. If you're going to run an alternator, this
takes care of the narrow belt adaptation problem. If you're going to stay with
the Lucas generator, you have to make a new pulley for it.