FROM BELTS TO CHAIN CONVERSION?

Hi guys,

Just wanted to find out if there is such a thing or if its possible. I tried searching for it but got tired after going thru all the threads and posts that was presented to me by the search button. Thanks!

Ken B.

 

I saw somewhere a while back were a German company was doing it for the 328 and was working on the 308. If I find it again, I'll post it.

mwr4440

 

Thanks!

 

Are not the 430's chain drive now? Or was it the 599? Seems possible with the proper components? Probably something similar to a doublerow timing chain? You'd have to be spot on with the pitch though or otherwise there would have to be a tensioner involved, that said there is the possibility of brg failure as is with the belts. So really no gain there?

 

Yes the 430's are chain, I don't know about the 599

 

It most likely can be done but I believe the cost would kill the idea. All you need to do is build a sealed case around the cam drive system and route a way to get some oil into the case. Next would be a tensioner assembly which you could get from any chain drive system now in use. So the cost of development will need to be spread over the cost of the conversion. I would not be surprised if you are talking about maybe $8-$10K modification. My 2 cents

 

+1

It would be a ton of work. I'm trying to make a belt drive heads fit on a chain drive block and that is a ton of work, but less than 1/2 the job you're talking about.


look around posts 448-500
http://www.ferrarichat.com/forum/showthread.php?t=170171

 

Why?

 

The slickest method, was one that I saw used on a Chevy 350, it was a Gear Drive, No chains, No belts, No noise, probably last the life of the car, that would be the ideal solution. (as long as we're dreaming)
But I'd settle for a 100k mile chain drive anyday.

 

Reliability and/or maybe some assurance that one may just drive his/her F-Car without the belts issues looming in the back of their heads.

 

Now that would be expensive!

 

The classic American V8 has one cam that is 5" away from the crank instead of 15" like an OHC enigne and makes that a lot more practical. Also having just one cam instead of four helps. A single gear as big as the starter ring might not be big enough to reach the top of the head. A cascade of gears up each head would be feasible, but at that point it wouldn't be simpler any more.

I say do it with bevel gears and a shaft to each head the way Ducati and Norton (and others) did it!

 

Chains break, too.

 

Seems to me it makes more sense to do the later style belt conversion that was buzzing around the site a few years ago. Current belt engineering would suit me fine.
Tom B.

 

There is no "...belts issues...". Ferraris with cam belts are and have been the most reliable Ferrari ever made and as long as the car is driven and the belts are replaced every 7 to 10 years or so, the risk of belt failure is very slim ... you are much more likely to have something else go wrong than cam belt failure. I would predict that a lot more Ferraris are wrecked, burned and/or stolen each year than have cam belt failure. Try to keep your non-tax exempt contributions to the 'Ferrari Mechanic Retirement Plan' to a minimum by not succumbing to the cam belt scare scam...

 

Tensioner bearings are the items that require close scrutiny.

The new owner of my 308 had the belts done last fall, they were 6 years old, mostly okay except for the hole in one belt from a small pebble, the size of a pencil eraser.

What was of even more concern was the condition of the idlers and bearings. I figured those were due, and they were.

More importantly, something of which I was unaware, was the poor condition of the cam drive sprocket bearings down by the crankshaft, BAD NEWS! The engine had to come out to change the inner set of bearings in addition to the outers. They were shot! A failure there would have trashed the engine block.


In the case of chains, guides and tensioners are a concern as well.

Compared to belts, the odds of a good chain breaking are a million to one. In 40 years I have NEVER seen a broken timing chain or heard of one breaking in a performance car. (except during catastrophic engine failure).

 

I almost had a failure in my 90 Q45 I was this ..... close. Chain guides failed. So it can happen.

BTW , Ghibli on Ebay is close to me so let me know if you're still looking. Bob S. Can travel for small dollars.

 

In a few of my Corvette's I would loose the timing chain at around 100k miles. Funny though the chain was OK but the OEM cam sprocket had nylon coated teeth to cut down on the noise. Well the teeth would break up and the chain would skip a few teeth and then the motor would go out of time and stop. On one of my cars I put the gear set in instead of the chains and it worked out great.

 

Hi Bob,
I saw that one. Interesting color combo. I wish they would show more pictures of the interior and engine, both good indicators on how the car was kept..
I'm pretty sure I won't be willing to pay the inflated reserve on that car so I'll have to be content to watch the auction. The market is too hot on those right now.
Thanks for the offer though,
DJ

 

I have had variable timing on numerous small blocks due to stretched chains. The timing would change depending on the direction of load. Worn teeth just added to the problem. Been there.

We would go to metal gears after that.

 

OK, I had one in my 1965 Mercedes 220SEb coupe let go. The car was totally not documented and who knows how many miles it had on it? 200k I'd say is the minimum, probably more. But it does happen. Anything can fail. Chains DO hold up better and last longer than rubber belts. If this engine was a rubber belt it would have done a lot less damage because it is a non-interference engine and the broken chain piled up against the crank sproket and made a mess of a few teeth.
Oh, and I've owned a lot of timing belt cars, driven them many hundreds of thousands of miles and never had one break.

 

So if a Ferrari cam belt broke in 200k miles, think how much less expensive it would be to then rebuild the engine than to pay for the 100+ cam belt replacement services at ~2k miles a year at $5k to $8k a piece...you would still come out ahead even if you just threw the car away at that point...

 

Ant luck with the search man? Do you remember what that german company was called?

 

Not very often. The usual failure is either the tensioner or the chain guide. In either case, it has about the same effect as snapping a belt, though they are usually good for around 100K miles and no time limit, which is a far sight better than what we get on the belts.

 

Agreed,
when chains do break they make a mess of what ever gear they bunch against. Most of the time all you have to do is slide the gear off and throw a new one on.

Either way, on an interference engine it's a bad deal. On a NON-interference engine it's a moot point.