Ideas for vibration problem in 59A

[A bones]

Hey hi Henry, I just want you to know of your status in my book. As someone who has spent his life educating you are a great success. I thank you for sharing your problems. We can all benefit. I wish I had something technical to share, as I have yet to go through my first V8 tear down. My motor reportedly had only one season in a boat. I have a long way to go before I hit the street. You have always felt it important to share ALL of your experience. I can't thank you enough for this. Here's to a smooth trip next time! Tom

[Old Henry]

Thanks Tom. It's always nice to get a little "pick me up" after taking a few blows that beat me down.

[bobH]

I'll be interested in comments from the engine 'guru's' on this one. Reason being, I also have a 47, with a 59 engine. I believe it is a 'replacement' (Ford parts counter) engine, because of some of its features. In any event, it has never been bored - still standard, and it has ALUMINUM pistons, which I have to assume it came with. Your comment regarding 'cast iron pistons' surprises me. Did your engine originally have iron pistons?

Originally Posted by Old Henry

Here's a question that has been raised by the mechanic. Does any change need to be made to the crank when replacing the original cast iron pistons with newer aluminum ones? The original crank that has just gone back into the engine only ever had the original cast iron pistons used with it. When it was replaced with the other crank, the pistons were also replace with newer aluminum ones. Does that require any change to the crank?

[Old Henry]

Well, I still have my original pistons. So, I took my trusty little magnet to check them and, sure enough, they are not cast iron as the mechanic had supposed. Guess that puts that question to rest. (Actually, it makes it moot, as we say in the law.)

Here's a picture comparing the newer three ring piston that was put in 50,000 miles ago to my original 4 ring. The newer three ring is 17.1 oz. compared to my original that's 17.8 oz.



And here's the newest SealedPower 4 ring that was put in 20,000 miles ago compared to my original so you can compare the newer three ring to the new four ring. The new 4 ring weighs 19.3 oz, 2.2 oz. or 10% heavier than the originals.



Would that slight difference in weight between the original pistons and these new ones require any changes to the crank? It didn't seem to when they were put in 20,000 miles ago.

[Mike B]

Originally Posted by Old Henry

In a way it's kinda good to see that I'm not the only one that has some difficulty finding an ideal mechanic locally. But, alas, we don't live in an ideal world. Everyone has their strengths and weaknesses. We find the best we can then try to supplement their weaknesses with our strengths and hopefully it will all work out for the best.

`

This is such a true statement...not everyone has a pile of dollar bills to send the engine across country for a guarantee,,,and even after that,,,what happens if there is a problem.

I think many offering advice, have been there and done that...so we who have an idea of what we want from a machine shop, sorta lay it out ahead of time to them..but, if you don't have the hands on and the experience of goofing something up, you really don't know what to ask for..you put your trust in the shop to get it done right.

Don't let the "you should have sent it to me"..type of response, or "what a bad machinist" you had discourage you.

The shop you took it to has owned up to it,,might be a learning experience for them...yes, will cost you time, but they;ll most likely get it right.

I often wonder about some on here at the Barn, "sounds like a bad carb rebuild"...etc...are they trying to help, or are they trying to drum up more business?

Anyway...they owned up to fix the issue, have them do i.

[Mike B]

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Originally Posted by Old Henry

Would that slight difference in weight between the original pistons and these new ones require any changes to the crank? It didn't seem to when they were put in 20,000 miles ago.

No..a shop would not change the crank to accommodate a piston, they would either adjust the piston (if possible) or advise you all need to be matched

[Kube]

quote:
Would that slight difference in weight between the original pistons and these new ones require any changes to the crank? It didn't seem to when they were put in 20,000 miles ago.[/QUOTE]

The crank does not care if the pistons are (ex.) 17 grams or 20 grams. What the crank does care about is that the rods with pistons attached are all of matching weight to one another.

[Ronnie]

Henry just using your numbers the reciprocating weight has increased by 124.8gr and you haven't included the new rings with the weight (Or the small end of the rod)so the figures are still short to get actual recip weight.Recip weight and rotating weight needs to be calculated to conclude the bob weight for 1 cylinder which in turn must be doubled for the bob weight for 1 crank throw. These are only rough numbers as the scale should be in grams to get more accuracy. The balance guru's will be able to with their vast knowledge give you a more definite answer as to the effects of having the recip weight increase that amount.
Here is some grass roots info on bob weights and balance programs to read.This in its self is another world.This is only a very small amount of info on engine balancing.I hope the inquisitive minds enjoy this tutorial on engine balance.

http://www.circletrack.com/enginetec...h_terminology/

R

[Walt Dupont--Me.]

Well, I've never got into this long thread but I'm going to a little story about balance an engine. A friend had 39 Merc. he asked me about building the engine, I said yes but I don't pull engines. He brought the car to another shop that pulls engines and rebuild them, I know the shop, nice guys but not really a flathead place. After they put the engine back into the car they called me to see if I would come up and listen to the engine, I went up, they started the engine , it idled good and sounded good, rev it up a little and a vribrate, I said I'd pull the engine and have the flywheel and pressure plate balanced. They did that and wheel and pressure was all right so they disassemable the engine. To get this story a little shorted. The problem was the original pistons 3 ring cast iron but very light, the replaced piston were 4 ring aluminum pistons and a lot heaver that the original, The balancer had to due a lot to the crank to get everything balanced. THATS WHY I HAVE ALL MY ENGINES BALANCED. Of course they have to be arsemabled right. Walt Don't worry about the spelling.

[Ronnie]

^^^^ More words of wisdom!!!!
Verify the clutch assy before any work continues it's a no brainer.

R

[Ol' Ron]

Just think, nobody balanced engines back in the DAY. Most major rebuilders don't balance their engines. And yet they keep running on and on. However I do think that Ol'Henry has a balance problem, not sure what is is. In all the years of racing, I never knew anyone that had their engines balanced. Because nobody did it. Bell In patterson Ny did it but you'd have to wait 6 months for it.

[GOSFAST]

Heads-up guy's, let me add some about balancing, the formula for getting the Flathead (and most others) bobweight balance numbers is as follows:

You take the weight of 2 large ends on the conn rods, 2 rod brgs (4 inserts) for the conventional single brg setup. (It would be 1 rod brg/both halves for a single early "dual" rod brg).

This gives you the rotating weight!

You then take the weight of 1 piston, 1 wrist pin, 1 ring set (single piston), 2 pin-locks, and 1 rod pin-end. These become the reciprocating numbers.

Some builders add a small number (3 or 4 grams) for oil, we've never done it. It is our belief the oil actually acts as a "dampener" when running. In reality the oil weight is a non-issue!

I'll place an example here using all factory numbers for an 8BA. The formula goes like this:

Rotating weight:
Total rod=528 grms. (Big end=402 / pin-end=126)
Large end on rods: 2 x 402=804
Rod brgs=52 grms: 2 x 52=104

Rotating weight =908 grms (This is considered 100% rotating)

Reciprocating weight:
Piston (OEM)=380 grms.
Pin (OEM)=120 grms.
Rings (4-ring piston)=64 grms.
Pin-locks (OEM)=2 grms. (In reality this is also an unneccesary number, but thats what they weigh)
Rod pin-end=126

Reciprocating weight=692 grms. (This is considered a 50% reciprocating balance job)

So, it would look like this:
(Rotating) 402 + 402 + 104 = 908
(Reciprocating) 380 + 120 + 64 + 2 + 126 = 692

Total (single) bobweight: 980 + 692 = 1600 grms. There will be a total of 4 bobweights, one for each journal, weighing 1600 grms each. When "building" the bobweights, their total number (1600) gets divided by 2 and would be 800 grms for each half of each bobweight!

The entire procedure and numbers above are for a 50% balance job. This is pretty much the "standard" for most V-8's, it is typical of the Flatheads.

You can change that 50% number to 48% or 52% (or more or less) and this would be considered an "under-balance" or "over-balance" formula. We use it occasionally for race-only builds where the RPM is consistently higher most times.

(Add) I have a balance card here from November 1988, a '53 Ford 239" Flattie, the bobweight on the stock rebuild was 1622 grams. Just for a comparison I have another from a 2009 build for a '53 Merc 255" using a 1637 bobweight! Things (weights) haven't really changed at all over the years!

(Add) These numbers sort of confirm what Ron is saying above here.

Thanks, Gary in N.Y.

P.S. I would add here from what we've learned through the years with the Flatheads (the same goes for many other mfr's as well) if you were to "mix & match" any OEM factory components there would be NO vibration issues whatsoever! Clutches and flywheels are mostly another issue.

[Kerk]

I would look for a problem with the clutch & or pressure plate and replace the piolt bearing while it is apart. Jmho kx

[Ol' Ron]

Where do you find a 380 g piston?? And would 20 or 30 grams make a difference when you drilled your balance holes??

[GOSFAST]

Originally Posted by Ol' Ron

Where do you find a 380 g piston?? And would 20 or 30 grams make a difference when you drilled your balance holes??

Hi Ron, let me answer the second part of your question first. There really is no way to tell??

Depending on the tolerances the shaft was balanced to from "day-one" by adding a 20 or 30 gram piston it could be worse or it may actually be better. This is something we don't know until the weights are made and you get an initial reading on the crank!

Having said that I can say with all honesty you will not "feel" any vibration from the piston differences you show above. But they would have to be consistent with all 8 pistons. If you wanted to verify this info a simple call to Federal-Mogul would give you an answer. It's always been their contention that if all 8 pistons were changed there'd be no issue! I tend to agree, to a point.

I just want to stipulate here I am NOT recommending not balancing ANY rebuilt engine's, doing this for a living we could NEVER run the risk of possibly having a vibration issue! We actually run 2 balancers here, sometimes together. We have a Stewart-Warner (hard-bearing deal) and a newer style CWT. ALL strokers regardless of mfr get done on the CWT (there are no hard brgs, shaft runs on Teflon) it makes the job much easier and it is much faster than the Warner! Both are very accurate however.

Now for the first part of your question, I have here with me now a piston that is in the photo below. It is a factory std bore Flathead, this particular one weighs 370 grams, the pin weighs 130, and it is part#EAC-6110-A, it is a FOMOCO piece! I have some "Nylen" stock replacements here, .030"/.060" over, that weigh 395 grams.

Thanks, Gary in N.Y.

P.S. One other item I missed about balancing, the shaft actually gets balanced on each end (obviously), this explains the holes in the front and rear c'weights. but it is also done on another "plane" (sort of like a long straight perfectly round 6.000" shaft), normally speaking and under ideal conditions if you remove X amount of weight from the front c'weight you would remove the identical amount 180* from the rear. You will find this consistent on almost all factory crankshafts, the problem gets way out in left field when you order these new stroker shafts. One reason we like the Eagle FH cranks, they balance up much better and much easier! (Here's the piston photo)

[Ol' Ron]

Don't know what I was thinking of. I some how thought the Ross pistons were heaver than that. About the balancing. Just for giggles, suppose you balznced an engine and then ghanged the pistons to some that were 20 or 30 g rams heaver or lighter. Would you rebalance the assembly??? By the way, have had the 294 over 5k, very smpth. Thanks.

[Bored&Stroked]

Originally Posted by Ronnie

What do you do if a clutch change is required when all is done on flywheel as a complete assy???

Most are balanced by themselves to "zero"
so a change won't the balance.

R

I agree that 'zero' is the best, but I've seen many performance machine shops still mark the flywheel and clutch - so I install them exactly that way. In the most recent engine builds that I do, I specify that I want a zero-balance on everything - as it makes it easy to change a clutch later on. BUT - I typically pull the flywheel and have them check the balance of both together . . . just to make sure. To me, the check is worth it -- as it is a whole lot easier than pulling the whole dang thing out later on . . . because the two components were not checked as one.

B&S

[Bored&Stroked]

Originally Posted by Ol' Ron

Don't know what I was thinking of. I some how thought the Ross pistons were heaver than that. About the balancing. Just for giggles, suppose you balznced an engine and then ghanged the pistons to some that were 20 or 30 g rams heaver or lighter. Would you rebalance the assembly??? By the way, have had the 294 over 5k, very smpth. Thanks.

I would - but I'm a bit anal when it comes to balancing as I've spun a lot of flatheads to 6K or more and they sure seem to hold together better when I know the balance is spot on.

[Ol' Ron]

Sometimes we confuse our 4k engines for the 8K engines. It's 250 bucks to balance areound here and the wait is forever.

[Ol' Ron]

Well I've asked that question of several NASCAR engine builders and they said it wouldn't make a measurable difference