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4cefedomni
06-12-2006, 02:57 PM
i'm doing a hybrid 2.5 and i'm getting ready to order my parts one thing i'm unclear of is what is the best choice of connecting rod i know most of you are going with stock t2 rods but i plan on pushing over 500hp with this motor i see on Cindy's site they sell shot peened t2 rods and aluminum race rods does anyone know anything about the aluminum ones? what the maximun hp they are good for and any real world experience with these. i'm a little hesitant on using aluminum as i have heard they can stretch under high loads.

mock_glh
06-12-2006, 05:46 PM
The highest HP engines use aluminum rods. The "stretch" is normal with these and it is standard procedure to build in about .060" head to piston clearance. You could also go with billet steel rods.

4cefedomni
06-12-2006, 06:07 PM
thanks for the info do you know if that clearance is built into the rods Cindy sells?

mock_glh
06-12-2006, 06:59 PM
You might call her and ask. I would guess that they do.

GLHS0658
06-13-2006, 12:59 AM
GRP Aluminum rods are rated @ 800 HP

John B
06-13-2006, 01:03 PM
Do you have to notch a 2.5 CB to use them?

GLHS0658
06-13-2006, 01:07 PM
I'll let you know...as soon as I get to it ;)

mock_glh
06-13-2006, 03:00 PM
Do you have to notch a 2.5 CB to use them?

Yes. They are pretty big on the large end. So big, in fact, that unless you narrow them down you have to bore the cylinders .040 over to get them in.:nod:

cams1021
06-13-2006, 05:29 PM
Aluminum rods are strong and light but won't last in a street engine - they stretch.

I went with eagle H-beams for a SRT-4 in my hybrid as they were the best bang:buck. Every dimension is the same as a stock T2 rod except the wrist pin. It uses a bushed floating .866" wrist pin instead of a stock .826" wrist pin in a T2 rod. I just ordered my pistons with .866" wrist pins, .020" over, with the extra valve reliefs and it works fine.

grinch-boy
08-29-2006, 11:15 PM
ok but is the weight the same as t2 rods

and what brand of pistonsdid you use

turbovanmanČ
08-29-2006, 11:41 PM
Yeah, they say aluminium rods in a street engine is a big no no.

GLHS0658
08-30-2006, 01:13 AM
Yeah, they say aluminium rods in a street engine is a big no no.

OLD School Aluminum rods but not the rods of today. Now they are made with a better alloy and hold up very well in street cars. Ken Crocie of H-O Racing uses them in his daily driven turbo-charged Pontiac 400 V8. In the mid 90's he had over 50,000 miles on those rods without fail. I don't know how many miles he has now. But he drove his 79 (Macho) T/A to work every day. Mecham racing produced this car back then like SLP did recently with F-bodies.

OLD school rods were made .010 short to allow for stretch at operating RPM's.
A six inch Chevy rod was 5.990

I will be happy to use an Aluminum rod. They are rated at twice the horsepower most of us will ever see. GRP and BME rods (smaller rods) are rated to 800 HP
How many of us are pushing the limits of a T2 rod with 400 HP?

Mike

turbovanmanČ
08-30-2006, 01:39 AM
OLD School Aluminum rods but not the rods of today. Now they are made with a better alloy and hold up very well in street cars. Ken Crocie of H-O Racing uses them in his daily driven turbo-charged Pontiac 400 V8. In the mid 90's he had over 50,000 miles on those rods without fail. I don't know how many miles he has now. But he drove his 79 (Macho) T/A to work every day. Mecham racing produced this car back then like SLP did recently with F-bodies.

OLD school rods were made .010 short to allow for stretch at operating RPM's.
A six inch Chevy rod was 5.990

I will be happy to use an Aluminum rod. They are rated at twice the horsepower most of us will ever see. GRP and BME rods (smaller rods) are rated to 800 HP
How many of us are pushing the limits of a T2 rod with 400 HP?

Mike

Very interesting, :nod:

Frank
08-30-2006, 09:22 AM
Or you can just go with SRT-4 Eagle H beam rods with SRT4 crank bearings! It is something like $220 for the set?! I have them in my Daytona. My pistons have the .901 pin, so i had to line bore the whole and put a new bushing in. If you have the .8xx pin, then you can just hone the bushing to accept the pin.


Frank

grinch-boy
08-30-2006, 11:35 PM
were did you buy them for 220.?

Ground Rat
08-31-2006, 08:12 PM
OK, so I'm using shot-peened TII rods. How much power can these rods handle? (at less then 6k rpm)

GLHSKEN
08-31-2006, 08:23 PM
I know a car with over 500 ft lbs using Bone stock TII rods.. I wou,ld say... more than enough

8valves
08-31-2006, 08:52 PM
I know a car with over 500 ft lbs using Bone stock TII rods.. I wou,ld say... more than enough

Just so long as you don't cross the 7K rpm threshold too often, that's a very important part of the equation.

AM

MiniMopar
08-31-2006, 10:25 PM
Yeah, it's also about the rev limit than just HP.

John H
09-02-2006, 08:59 AM
I run a set of cunningham rods. Maybe overkill....I don't know. Look beautiful, works of art.
http://www.cunninghamrods.com/products.html

John H

GLHS #935

2.216VTurbo
09-03-2006, 12:25 AM
I run a set of cunningham rods. Maybe overkill....I don't know. Look beautiful, works of art.
http://www.cunninghamrods.com/products.html

John H

GLHS #935


I like the looks of Pauter and some local guys use them in there big $$$ motors $800./set though:(

Does Cunningham have an 'off the shelf' rod for us or is it custom every time? Aout how much is a set?

TurboJerry
09-03-2006, 02:33 AM
The rods in a turbo engine have an easy life, they are being "pushed together" when in boost, where as in a N/A application, they are stretched everytime during the overlap period. I guess this is why good rod bolts are important. But 7000 is the rpm limit for T-2 rods from what I can tell..... You can go higher in short spurts, but I woulden't run 100 miles that high on rpm..... Oilver rods are good too.

Ground Rat
09-03-2006, 05:59 AM
The rods in a turbo engine have an easy life, they are being "pushed together" when in boost, where as in a N/A application, they are stretched everytime during the overlap period.
I don't get it. :confused:

John H
09-03-2006, 07:20 AM
I like the looks of Pauter and some local guys use them in there big $$$ motors $800./set though:(

Does Cunningham have an 'off the shelf' rod for us or is it custom every time? Aout how much is a set?


They were custom when I bought them a few years ago. The set was around $700...maybe more now with the cost of steel. I can't really say they're any better than the other choices and my car doesn't make alot of HP, but so far, so good. The Pauter's do look nice.

John H
GLHS #935

Directconnection
09-03-2006, 11:23 AM
Oliver is a very qaulity conciensus company. They seem to really take extra care with their products. They send you their special lube and a plastic laminated protective installation sheet along with a color pamplet on the do's and don'ts of their installation. They do have weird torquing requirements, etc..

My favorite is Crower. Crower supposedly offers the best steel rod out there. Called Maxi-lite or something to that extent. Almost as light as an aluminum rod, yet very very strong (and expensive at $2,000 a set for SBC)

The rod bolts in these are $35 each and you cannot touch the threads as the oil from your fingers will corrode over time.


But, bang for the buck, Eagle rods. They are junk as far as performance is concerned. Make sure they are resized as their in house machining leaves something to be desired. Meaning, when you torque them up to the recomendation, they will not come out round and to size.

cordes
09-03-2006, 12:54 PM
Yeah, it's also about the rev limit than just HP.

+1 the stress on them increases exponentially with RPM.

John H
09-03-2006, 09:15 PM
But, bang for the buck, Eagle rods. They are junk as far as performance is concerned. Make sure they are resized as their in house machining leaves something to be desired. Meaning, when you torque them up to the recomendation, they will not come out round and to size.


Amen to that on the Eagles. The set I bought for my Neon were completely out-of-round and had to be re-sized. I should have just ponied up for something of quality. Would have cost the same in the end.

The Cunninghams I bought for the GLHS measured spot-on by the same machinist and were perfectly balanced. They don't even have a balancing pad on the big end.

John H
GLHS #935

TurboJerry
09-04-2006, 02:58 AM
During the overlap period, there's pressure holding the piston down somewhat, where as a NA engine there's only the Atmosphere, so the rods go through more stress......

Ground Rat
09-04-2006, 06:13 AM
Interesting.