[JZ9C1LT1]

I'm building a 355 short block with all the machine work and balancing already done. Its a 97 LT1 +.030 over 4-bolt main block, Mahle coated forged floating pistons, Eagle I-beam forged rods, stock crank.

I've been hearing conflicting stories about the Eagle I-beam rods. Are these rods strong enough to make say 400-500 hp? I plan on using 150 shot of nitrous on this engine. I know tuning will be critical for this much power and will put an emphasis on this before running nitrous.

Can these rods hold that much power or should I change to there H-beam rods?

 

[alwyswntd1]

h-beams,i also heard that the i beams will not hold on the giggle juice

 

[GuillaumeC]

They are rated to 500hp and 6000 rpm... looks to me like it wouldn't be a big improvement over stock rods.

FWIW, I ran stock rods for a couple of years in my car. Ran mid 11's on nitrous @ 116-117 mph and 120+ mph with the turbos.

When I took it appart after breaking a piston the rods still looked fine... no weird wear on the rod bearings.

My opinion is that if you're going to upgrade then UPGRADE. If you dont plan on making alot of power I'd stick with the high quality OEM rods vs the "budget" imported rods.

 

[Ram Air 383]

Not all I-beam rods are the same. However, those are not any better than stock and possibly weaker.

 

[Blue Wail]

Those rods should be fine.
I have them in April's ImalaMASTER engine
which used to be in the Black Bat where
I would spray the heck out of it.
It still runs great.
Detonation is what will kill a rod.
Keep the timing at 28 degr or less when spraying.
31 degr max when on motor.

-Nab

 

[alwyswntd1]

Those rods should be fine.
I have them in April's ImalaMASTER engine
which used to be in the Black Bat where
I would spray the heck out of it.
It still runs great.
Detonation is what will kill a rod.
Keep the timing at 28 degr or less when spraying.
31 degr max when on motor.

-Nab

yes,well said i was reading on a few i rods myself last night after i posted and you are correct.i was going by one of my buddies experience not my own.

 

[Karl Ellwein]

I'm also thinking that even though those eagle I beams are light weight and possibly not the most sturdy of all rods, that since you have a lighter piston with the Mahle, that the rod should be perfect for your combo. I would not use that rod combined with a sturdy/bulky/heavy blower piston, (although it may still work...who really knows and who has conducted testing with this?).

I think we have the same combo Keith in our 355 engines. I have a stock crank, cheap Scat I-beams, and Mahle flat tops. I would not hesitate to run 175hp nitrous on my combo but like Nabil said it is important to have a good tuneup.

 

[55belairgasser]

Karl, I have a set of Ross Racing pistons, and a set of Speed Pro plasma moly rings that I won at this past years Daytona GOFASST show(thank you again for donating them!). I will be building up a 355 this coming year for the Impala. Should I spend the money on a set of H rods or stick with the stock ones? I will not be hitting it with a super charger of a set of turbos, just a natural aspired street engine. What about the crank, dragon slayer or stock good enough to hold up to 450 HP? I appreciate your opinion. Wish I still lived in PA., I would have you put it together.

 

[JZ9C1LT1]

Guys,

Thanks for the info! I already have the parts and everything is balanced so now just assembling the engine is all that is left. Can't wait to run this 355 next year. Now only to decide on a top end setup! (I have a good idea, just need to pony up the dough)

 

[Karl Ellwein]

Karl, I have a set of Ross Racing pistons, and a set of Speed Pro plasma moly rings that I won at this past years Daytona GOFASST show(thank you again for donating them!). I will be building up a 355 this coming year for the Impala. Should I spend the money on a set of H rods or stick with the stock ones? I will not be hitting it with a super charger of a set of turbos, just a natural aspired street engine. What about the crank, dragon slayer or stock good enough to hold up to 450 HP? I appreciate your opinion. Wish I still lived in PA., I would have you put it together.

Hi Lance,
If I remember correctly those Ross pistons are for a "383" (3.75" crank with 6" rod) so you won't be able to do a 355 with a 3.48" stock size crank and those pistons. What does the compression height on the pistons say? (1.131"?)
So to answer your question, you'll need a stroker 3.75" crank of any brand. And I think that since those are the nitrous pistons that you would be best off getting H-beam rods (Scat or Compstar). Or Scat I-beams with the 7/16" rod bolt, or Lunati I-beams, or, or, or.
Karl

 

[Karl Ellwein]

Also remember those Ross pistons from the GoFasst raffle are flat tops so you want big combustion chambers on your heads.

 

[Dan Fahey]

I'm building a 355 short block with all the machine work and balancing already done. Its a 97 LT1 +.030 over 4-bolt main block, Mahle coated forged floating pistons, Eagle I-beam forged rods, stock crank.

I've been hearing conflicting stories about the Eagle I-beam rods. Are these rods strong enough to make say 400-500 hp? I plan on using 150 shot of nitrous on this engine. I know tuning will be critical for this much power and will put an emphasis on this before running nitrous.

Can these rods hold that much power or should I change to there H-beam rods?

My experience from Stock Eliminator Master Engine builders.
The Stock Rods are not so much Power limited as they are RPM limited even with ARP fasteners.

Under 6500rpm they are ok.
Above 6500rpm have them Cryoed and Polished and use a lighter Piston.

But for better investment get a set of good aftermarket Rods and Pistons

Dan

 

[Big Kahuna]

Now only to decide on a top end setup! (I have a good idea, just need to pony up the dough)

Did you clear your heads/cam choice with Dwayne, sir?

 

[KW Baraka]

Did you clear your heads/cam choice with Dwayne, sir?

cwm2 LOL....LOL cwm2

 

[55belairgasser]

Karl, The Ross pistons are:
Part # 90765
Bore 4.030 Net Dia 4.026
C.H. 1.133
Ring Grove 1/16 1/16 1/8
Ring Land .160 .157 .078
Pin .927 2.500 DBL
Net Dome CC 0
Dome Height 0
Dish Depth 0
Int V.P. Dia 2.20 Depth .250
Exh V.P. Dia 1.80 Depth .220
Thanks for any and all help. I guess I will be doing a 383 then!

 

[Karl Ellwein]

Hi Lance,
383 it will be. Those are 383 piston for 6" rod...
the standard 383 piston for 6" rod is 1.125" compression height but Ross always adds .008" to their piston so that makes it a 1.133"
It's a good piston for natural and especially for nitrous. It's not a good blower piston because it's a flat top. Also you have to be careful that you don't use small combustion chamber heads because your compression ratio will be high. You'll want 58cc minimum and 62cc best.
Karl

Karl, The Ross pistons are:
Part # 90765
Bore 4.030 Net Dia 4.026
C.H. 1.133
Ring Grove 1/16 1/16 1/8
Ring Land .160 .157 .078
Pin .927 2.500 DBL
Net Dome CC 0
Dome Height 0
Dish Depth 0
Int V.P. Dia 2.20 Depth .250
Exh V.P. Dia 1.80 Depth .220
Thanks for any and all help. I guess I will be doing a 383 then!

 

[55belairgasser]

Karl, thanks for taking your time out to answer my questions. - Lance