I don't know what's my max HP goal is, but I would like to see what people think about the L19 or the 1/2"? I'm already way over my budget for this built motor. Do you guys think the L19 is ok or the 1/2" is a must? I know the 1/2" is stronger, but i ran out of mula This is what my built long block consist of:

Arias Extreme Duty pistons .20 overbore
Pauter rods
Darton MID sleeve
ARP main bolts
ARP L19 head studs
Rear cylinder coolant bypass mod
OZ1's head strengthening mod
Ported and polished heads
5 angle valve job
Tomei 268 cams
HKS Metal Head Gaskets
JWT HD Valve Springs

 

I would have opted for the 1/2" head studs over the Head strenthening mod, which IMHO is a joke...
L19's are good, but for major boost, like 18psi and up the 1/2" are cheap insurance...Problem is, the block and heads have to be drilled out.

 

^that's where it gets hairy

 

Having the block and heads drillied are not hairy. I have the 1/2 studs, and hks gaskets. It cost more but I did not want to ever have to open my engine again. I also plan on running at least 20psi in the future on race gas. With no sleeves .

 

Sounds like a badass engine, but IMHO waaaay overkill for a TN kit.

 

I'm waiting for the Stage 2. Also looking at the Greddy TT setup and sell the TN kit. The engine is paid for and is at GT-Motorsport to be build. I'm considering the 1/2" then sell the L19.

 

What kinda power would you want with the twins? If you want to save some money you could change a few things.

 

Hey Z PHAT

Im planning an APS TT with a built motor and trying to figure out my budget. Can you please tell me how much you have into that motor? PM me if you like.

Thanks and nice work so far!

 

+1

I dont like the idea of drilling and tapping an Al block. The standard ARP studs in place of the stockers is plenty strong. Ppl that try and get that last 5 rwhp by running aggressive timming are the ones that pop their heads. No head stud is going to guard us from high peak cylinder pressures on an open deck.

 

+1

 

+1

 

Thats where the misconception is.The standard L17's are basically an OEM replacement HEAD STUD as apposed to a BOLT, slightly stronger than stock. Peak Cylinder pressures do have alot to do with it, but is not 100% the reason.

 

So, the stock head bolts would be just as good as the standard L17s? I heard that the stock bolts are pretty damn strong, but figured the stud would be better then a bolt.

 

High rpms are worse than pressure on an open deck block. Todd from built Z motors has equitment made to drill and tap the block. Its a plate that was made by Sandia Labs equitment, or something to that effect (It is also highly accurate and basically impossible to put a stud in crooked). Accoring to you guys that are scared of drilling and tapping it, than boring the block should scare you just as bad.

 

The cylinder is iron.

Have you ever tapped anything before, let alone aluminum? Its not easy and takes alot of experience.

 

I have 1/2" Studs. I also have a timesert in one of my heads in a sparkplug hole. When the piston came off of the rod it pushed the sparkplug out of the head and destroyed the threads. I have 10k miles on my engine so far, it has no problems. If it was going to come apart, I am sure it already would have.

Here is some information on timeserts
http://www.timesert.com/html/faq.html

I have them in the block for the studs and one in the head for a sparkplug.

I have retapped threads before, i have also pulled a broken sparkplug out of the head of my porsche 928, with no ill effects. Aluminum is not something to be scared of when there are some highly reputable machine shops that can perform this with relative ease.

 

No, not exactly...An L17 is an oem "upgrade" replacement.A stud is always stronger thana bolt.I dont know the physics behind it, but its just that way..An L19 is a different material, that allows you to put higher Tq without the risk of breaking the stud.
We opt for 12mm on most builds and 1/2" studs on the race car, just as a precaution...
The people pushing L19's obviously have a vested interest.Not to say it does not work "BETTER" than a stock, but just to say there are other options available that will almost guarante you wont lift the heads from weak head bolts.

 

If that is what you think, your not 100% on point..Have we seen to date one failure related to the cylinders and the open deck design directly??
Granted, Open decks are more fragile when it comes to detonation, but usually a properly tuned motor wont detonate. A good alternative are steel darton sleeves leaving the open deck design, which will sustain lots of HP believe it or not..

 

No doubt about it. There are plenty of good machine shops that can drill and tap the block for larger studs. Then again, there are prob just as many that are willing to accept the job whom are ill qualified or equiped.

I would guess 90% of the ppl building their blocks are setting goals for sub 600 rwhp on stock sleeves. At those power levels, why complicate the build with another variable?

I just hate to see ppl mislead to the idea that simply putting the best and newest of anything will insure a problem free project.

 

I may not be 100% on point about the open deck considering rpms. I have read this information on porsche forums with the 928/944 engines wich are both open deck blocks. The belief and the research people have done came out to that high rpms cause the tops of the cylinders to wobble and distort. None of those cars have seen a failure of the the open deck under boost. The reason i did not sleeve my block, is that in all the research i did before building my engine, there were no records of failing sleeves.