Gtd? Flywheel query

I'm hoping somebody can help me on this.

I've been dealing with a clutch manufacturer in the UK, to cure a slipping clutch

No problem, he said, send me your clutch and flywheel and I'll sort it out.

Unfortunately, he re-balanced the flywheel out of balance with the crank, and is now trying to source a new flywheel, and later have it balanced on the engine.

The problem is, he cannot identify the flywheel.

I suspect it may be a Ford V6 Transit/Capri item, re-drilled to match the 302 crank.

Can anyone definitively identify the flywheel?

Here's hoping.




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I think its off the Essex V6 engine.

Maybe worth giving the guys at Burton Power a call to see if they can help identify from the pictures.

Sorry I can't help from here, as I mentioned to Frank the other day we don't keep a lot of historic info for older stuff
It's a V6 Essex, " modified " to fit the V8 crank. Unfortunately not the same balance, we used to deal with the firm that modified them for GTD and their balancing tecnique involved putting a washer under the edge and then machining the flywheel flat, hey presto, you had nore external balance! We don't use that firm now.

The original balance is now lost, all you can do is to return it to the V8 28oz and hope it isn't too far out. I can do that if you want but might be better to start again with a billet steel jobby, give Mick a call at Southern GT.

I just went through this getting a new flywheel;
Early 302 ('81 and earlier use a 28 0z weighted flywheel)
later ('82 and up use a 50 oz weighted flywheel)
I have seen flywheels that have interchangeable weights, but you may be dealing with some space limitations and the diameter may be an issue for your bell housing.
Hope this helps a bit
Umm - can someone tell me why, if the flywheel is 'balanced' and spins without viabration, why would it unbalance the crankshaft as well .. unless of course both crank and flywheel are balanced together?
Umm - can someone tell me why, if the flywheel is 'balanced' and spins without viabration, why would it unbalance the crankshaft as well .. unless of course both crank and flywheel are balanced together?

Most Ford V8 engines and ALL small block engines in stock or near stock specification rely on a degree of external balance, ie. a weight on the flywheel and an opposing weight on the damper. On it's own the crank etc is not in balance hence the problem with this flywheel that is now perfectly balanced but useless when bolted to the crank.

Moral of this tale, when employing "experts" to do work for you, try and find one who actually knows what they're doing !



If you are replacing the flywheel take the opportunity to go away from the standard steel flywheels especially as you seem to have enough grunt for the original clutch to slip. Mick has the right bits.
Exactly, if I recall, the weight is added to the flywheel to reduce the size of the counterweights on the crankshaft. There might be more to it than that, but essentially, I believe that was the reason.


Mike Pass

Hi Geoff,
Sorry to hear about your continuing problems. Unfortunately you have now lost the correct balance on your flywheel for your engine and no easy way to restore it. I cannot understand why this clutch guy has altered the balance on your flywheel as all he needed to do was ensure that the new clutch cover was neutral balanced. I think the GTD flywheels were Ford Essex engine flywheels which were redrilled to fit the sbf crank. You do not say what clutch you are now going to use so it's hard to say what your exact best option is. The Essex flywheels are a bit old now and will need machining and may be a bit heavy. I would think that a new steel flywheel from Mick Sollis is good point to begin. However check with him about the clutch you plan to use as the correct bolt holes and locating dowel holes will need to be machined into the flywheel. Mick usually uses the AP setup. You will need to get the flywheel and clutch assembly balanced whilst it is mounted on your crank. You could try a flywheel which is balanced to the normal sbf "out of balance" but really the only way is to do the job properly and get the whole bottom end balanced up correctly as a complete assembly of pistons, rods, crank, flywheel and damper. A pain I know but the engine will be much smoother and long lasting with a good balancing job.
Hi all,

On my recently acquired GTD, I have some engine vibrations above 3500 rpm.:furious:
I wonder about the flywheel balancing...

Few years ago, the engine blew off, and the owner put in it a new crate engine SBF 347ci from Ford Racing (D347SR).
The mechanic bolted on the crank a Ford V6 flywheel from a Capri. He said me that it was not balanced...and does not need it.:stunned:

If I read the technical documentation, which comes with the crate engine, I can read "Balance Offset : neutral balance".
Does it mean that this particular engine is like internally balanced (and not to 28 or 50oz off), and that the flywheel then only needs to be balance at 0 (i.e. neutral balance ?):huh:

You can download the pdf here :

Thanks for your help !:thumbsup:


Mike Pass

Hi Pierre-Louis,
On the pdf it says that your engine is neutral balance. This means that both your flywheel and crank damper must be neutral balance also. You can remove both these components and have them checked for balance by your local engine builder. You will need a puller to remove and replace the damper from the front of the crankshaft. Crank dampers are usually bought with whatever balance you need. If your damper is not neutral balance it might be a good opportunity to get a better quality item fitted.
Ideally both these components should be balanced with the crank. However if you check the state of balance of these two components and get them individually balanced with a neutral balance you should be a lot nearer the correct state for your engine. Do not run the engine if you have vibration issues as you may damage bearings etc.
Hi Mike,

Merci beaucoup for these infos... :thumbsup:

I think the damper came with the crate engine, Ford documentation says it's part # M-6316-C351 on D347SR engines.
:idea: Mais bon sang ! On Ford racing website, it is said that "Damper has removable weight that allows use as a neutral balance unit for internally balanced crankshafts" !!

Could one of these weight been "forgot" on the damper ?

I will first check if these removable weight are bolt on my crank or not, fortunately I've found the detailed Installations Instructions : (thanks to the Blue Oval guys !)
Hope it could be removed without removing the damper itself.

Regarding the vibrations issue, I'm not sure of what happened really. Under 3500 rpm, everything is smooth as silk, and just at 3500 I can feel/hear some unusual noise growing up (not really shaking the whole car however), and at 4000 the shifting rod linkage begins to shake like hell !

After checking the damper, if no removable weight issue, think I'm gonna neutral balance the flywheel, just to be sure, and fix that @#$% rod shift linkage which is not correctly built.



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The D347SR crate motor is internally balanced, it does not need external balance weights.
The V6 Capri flywheel DOES have an external balance weight, you need to sort this before it all ends in tears.


For what its worth, I think I had a balance problem on my last engine in my Dax. I have a v6 flywheel on my engine. The engine was originally a 302 cu in ford. I bolted it all together and off I went. It seemed fine until I used it in anger. I seemed to have quite a bit of vibration, but was never too sure what it was. Various bolts came undone.e.g. Starter motor bolts; drive shaft bolts, and the one that did the engine - the bolt / thread that screws into the top of the holley carb. It dropped through the inlet manifold and into the cylinder. Shattered a piston, bent 2 rods,and put a hole in the block. (There's a picture on here somewhere of the damage).

I now have a 347 stroker, which a friend who is much more knoweldgeable that me, sourced all the parts and built for me. He made a point of getting the right harmonic balancer, and that, with the new crank, flywheel and clutch assembly was then sent for balancing. Once the new engine was in the car, a total transformation. No vibration !!

Funny that. Well not really, as it cost me a new engine to find that out !!

Ouch !

Stephen, it seems I have the same issue :cry: about undone bolts.

I live near Paris (south) and purchased the car in the south of France. Paid it, jump in it, and off I went on the higway for 500 miles to Paris...

Somewhere, between Avignon and Lyon, heard a metallic grinding noise coming from rear right and every electric devices became suddenly mad.
It stopped completely after less than 10 sec. I was in a too dangerous area to stop on the emergency lane (RHD car, with these special doors...). As everything works normally, I went on few miles to the next gas station.
Stopped the car, opened the rear clip and ... surprise ! No more starter motor. It just fell off !:furious:

I m' not gonna touch this car before checking the flywheel and damper balance !


Hi Pierre Louis

You have a PM.

Hope we don't appear to have hijacked this thread, but I think its all relevent to the original question.



Mike Pass

As far as I am aware the V6 Essex engine is not internally balanced. Therefore the flywheel if fitted to your engine without neutral balancing will cause very severe engine damaging vibration.