Broke timing belt on hwy!!

[Jtroiano]

So belt shredded teeth last night at about 70MPH. So I'm sure some valves got bent.

So I'm going to take the engine out and rebuild. (mechanic and own own shop)

It is a 99 quattro with some GIAC tuning and a KO4 turbo. (bought it that way)

It ran great before.

My question is? If I want more power and rev higher what are the weak parts??

I read Rods? Valves? Springs??

Also can I get rid of the hydrolic lifters? Cant stand the clacking when starting!!!

I'd normally do a lot of searches but am in a bit of a rush now that its messed up.

Thanks.

Jon

[Seerlah]

You need the lifters. If they were clanking on start up, that was an issue all by itself you seemed to have not known was. It is actually a common issue, and people have found that using Lucas heavy duty oil stabilizer band aided it. And I say that because you really should have replaced them.

Anyways, here are the jiffs:

Stock rods are good till roughly 350tq at the crank, but can be pushed further depending on tune and how good your setup is put together (ie no timing pull). But that is the general agreed upon breaking point. And that point has been learned by numerous people breaking a rod and placing a nice hole in their engine block. Real world testing. The rest of the "short" block is stout to around the 550-600hp mark. Not sure who ever tried to push it further than that with just upgraded rods and stock displacement without upgrading other parts. Then there is the normal aspects of boring, forged pistons, stroker crank, etc. But just forged rods will make the bottom end rather stout.

As for the cylinder head, it depends on what your goals are. But upgrading the exhaust valves is a def when pushing a lot of air. Stock ones are sodium filled, and will sort of fall apart on you with enough heat. Upgraded springs are for if you want to rev to roughly 8.5k rpm. Unless using a turbo efficient in those rpms, it is rather pointless. Same thing goes for the cams. Don't do upgraded cams without upgraded springs. Waste of money.

[Jtroiano]

You need the lifters. If they were clanking on start up, that was an issue all by itself you seemed to have not known was. It is actually a common issue, and people have found that using Lucas heavy duty oil stabilizer band aided it. And I say that because you really should have replaced them.

Anyways, here are the jiffs:

Stock rods are good till roughly 350tq at the crank, but can be pushed further depending on tune and how good your setup is put together (ie no timing pull). But that is the general agreed upon breaking point. And that point has been learned by numerous people breaking a rod and placing a nice hole in their engine block. Real world testing. The rest of the "short" block is stout to around the 550-600hp mark. Not sure who ever tried to push it further than that with just upgraded rods and stock displacement without upgrading other parts. Then there is the normal aspects of boring, forged pistons, stroker crank, etc. But just forged rods will make the bottom end rather stout.

As for the cylinder head, it depends on what your goals are. But upgrading the exhaust valves is a def when pushing a lot of air. Stock ones are sodium filled, and will sort of fall apart on you with enough heat. Upgraded springs are for if you want to rev to roughly 8.5k rpm. Unless using a turbo efficient in those rpms, it is rather pointless. Same thing goes for the cams. Don't do upgraded cams without upgraded springs. Waste of money.

Thanks for the info. It all makes sense. I was planning on a belt just didnt get it done.

What brand rods and piston are the hot ticket?
What is the breaking point of the stock 5 speed? With no clutch dumps at 7k.

[Seerlah]

With these cars, don't go by what the manufacturer says when it comes to the TB. Change it every 60-75k or 5 years. Whichever comes first.

As for brands, it once again depends upon your goals. For example, why spend $800 for a set of rods when a set of $400 rods can do the same thing. Rods have their breaking point, and some are just lighter and more strong that others. Then there are things like rifle drilled, force pinned oiling rods, etc.

I am actually about to build my "short" block once my parts arrive. I suspect my piston rings are the culprit, so taking this opportunity to upgrade. I am on a budget, so I am using 144x20 Brute rods with AEB pistons (I have the AWM). Picked up both for $500 shipped. Decent deal, but it can always be done for cheaper. You basically need to decide what want currently and what your ultimate goal with the vehicle is, then go from there. For example, I want 400whp on pump gas a decent boost (ie 25psi). So, simple forged rods, cylinder head work, and bigger turbo can do that for me. Currently running a T3 GT2871R .63 A/R on a completely stock block at 17psi.

As for the tranny, it will take a crap on you if you beat on it. That should go without saying. But you can pick up used trannies anywhere from $150-400, so it's not really that big of a deal. And nobody is going to dump the clutch at 7k rpm. Not sure what the sweet spot was for drag racing. Need to search that info, but it was around the 5k rpm mark. But for just enjoying your vehicle, the tranny can last a while as long as you don't constantly beat on it. That would include constant 3rd gear pulls. There is a shaft that flexes and damages your tranny. But there is also a product out designed to alleviate the clutch engagement to help the shaft last longer.

http://www.ringer-racing.com/product.sc?productId=130&categoryId=2