Porsche-O-Phile

Title says it. Which is better and why?

Also what are the advantages of rifle drilling? Just better oiling? Will this weaken the rod? Anyone done it?

ehall

Here's a thread from Clarks garage that I found interesting. The jist is that they aren't exactly the same size, but you'll see in the thread. E http://clarks-garage.com/phpBB2/viewtopic.php?t=1814

FAST44

The rods are stronger than stock rods. They also weigh about 110g/each less than the stock 951 rods. The more you up the HP the more stress on the rods. The rods are so strong that the drilling would not make much difference.

Ski

If you put a 3.0L crank in a 2.5 block, these rods will also prevent you from having to machine the girdle and block, as you would have to do if you used stock rods with the crank. ex: 2.8 stroker motor

ehall

Yep, that's pretty much what that thread was about. They are obviously both good products. It would appear that it's more of a question of application. E

Porsche-O-Phile

That's why I'm asking - I'm planning on adding a 3.0L crank to my engine project and will go with either one or the other for new rods. Carrillo makes titanium rods (!) but (1) they're over $3,000 and (2) I think they're probably overkill. The engine will run 8.0:1 compression and approximately 18-24 psi of boost.

ehall

It might be worth going over to Clarks-Garage, and getting some first hand info from him. He runs a 2.8 with a 3.0 crank. He does almost all of his own stuff, as you probably already know, and is fantastic about replying. You might post this on his performance board. There are some good threads there on the subject.

Ski

I'll stay on Jim(jwl) to keep pics of his 2.8 build. He has 3.0L crank, Carrillo rods, new pistons with the wrist pin higher, .076 MLS gasket to get compression to 8.3:1, his head from Leo Goff at Memphis Motorwerks only has 5k on it, and I think his new Vitesse Stage IV is ready next month. He sold the Vitesse Stage II to the guy who he is rebuilding his complete engine - blew a head gasket at TWS, 90k car, stock, and scored #1 cylinder.

Weston Dillard

I've been running Pauters in my 3.0 for about 3 years now. After 2 years of hard track use and 100% reliability, I pulled the pan to replace the bearings and found that the rod ends were blued. It looked like they didn't have enough side clearence. They measured out to be right at the minimum allowable, but that was after 2 years of wear. I pulled the motor apart and sent them back to Pauter. They re-bushed the small ends, re-sized the big ends and reduced the side clearence. They only charged me $160 including shipping and when I got them back you cold not have known they weren't new. I'm a Pauter fan.

West

Danno

I wouldn't use the Pauter rods past 7000-7500rpm. Carrillo's the choice for 7500-8500rpm redlines. There's a difference in optimizations between I-beam vs. H-beam designs.

m42racer

Carrillo. No contest

They are not really an "A" beam in the true sense of an "A" beam rod. Something quite unique to Rod design. Known to be one of the weakest and more flexible designs out there. One of the cheapest if not the cheapest you can buy. You get what you pay for.

Russ Murphy

What the h#@@ are you saying?

special tool

Yes m42 - I didn't get that, either...

RogueM3

He is saying, though stronger than stock, A-Beam rods are nowhere near the same level as H-beam rods.

This is no secret though...just look at the pricing difference, as well as what supras/high boost cars in general are running in their built motors.

In regards to "not really and A beam in an A beam sense" I dont understand that part.

APKhaos

Both target rev ranges are OK for a prepared 911 engine, but way out of the question for the 951 engine, right? My stock class race head running stock boost had seven [count 'em....SEVEN] broken valve springs. Not sure even after-market springs will make this valve train safe much north of 7000. No power there with stock setup, but sometimes the temptation to stretch a gear can make a pass possible.