I'm going to do an le2 package from lloyd with stock valves to help out my fuel mileage. I got the block bored .30 over and have a set of mahle -5cc forged pistons. As far as the rods and crank, i'm thinking of going with eagle SIR I beam rods and reusing the crank. Will this combo work good revving the motor to 6500 rpms and having around 400 rwhp. My machine shop guy doesn't trust the rods or crank but from what i've read they should handle that combo fine. Any input would help.

 

That sounds like a sound buildup to me... those parts will work fine if all the clearances are checked (pin bore, rod clearance). As for the crank, have the journals polished and then balance the puppy (easiest with the stock flywheel/flexplate, but a internal balance stresses the crank less)

The stock valves aren't going to help fuel milage, don't know where you got that part from. A 355 with what you are looking at for a top end can do 410-420rwhp with bolt ons and some good tuning.

Bret

 

i'm using the stock valve size i should say instead of the 200/156 valve sizes. That way i don't need real big injectors and tb to compensate for the increase fuel flow thus better gas mileage. But that confirms what i thought about the setup. Thanks.

 

Considering the power level you are shooting for I find myself wondering; is there some reason you're not re-using the stock rods?

Because they're a lot stronger than they get credit for. Stronger than the old "Pink" rods.

 

I don't know who's been feeding you packs of lies, but you won't make anywhere near 400 rwhp with stock injectors.

If you're concerned about gas milage driving an f-body, you're in the wrong hobby. Because mine gets about 12 mpg.

 

Had I stayed with a 355, I would have used those same parts for my shortblock.
You've made good choices in parts, but you may wanna look for a different
shop/person to put it together.

 

the motor had almost 130k on it so the rods might be a little worn out and if its revving that high i'd like to have a lighter rod anyway. As far as injectors i never said "stock injectors" i said "real big injectors", i've got 32# injectors and a 53mm tb so you know.

 

Yeah i hear ya he's just a better safe then sorry guy and he likes to build things only with h-beam rods and forged crank even if you don't need it, which is overkill but just the way he is but he does awesome work. And i'm not looking for great gas mileage but i got 24 highway before and i'm figuring i'll get 15-18 now.

 

I'd rather have a set of stock rods than the Eagle "SIR" rods. Just IMHO.

Rich

 

I retract my earlier statement. You might want to consider at least 36#'ers. I've got 30#, and I'm moving up to 42#'ers, LE3 heads and LE3 cam, and a 58mm TB.

Edit: I'd recommend good rods. I'm going to build a 355 shortly as well with stock crank, and that's something I wouldn't skimp on.

 

I'm running a stock crank eagle H beams and have been to 7400. You should be fine with what your looking at. In fact..the factory rods are just fine with what you want to do. As far as injectors..I'm running delphi 37s @ 50 PSI and with 476 rwhp and spinning to 7400ish Im only running 80-85%. My stock crank also has taken some nitrous hits on my old head setup(lt1) and made 505 rwhp and 565 rwtq. Just build it right and you will be great for a looong time even if you reused the stock crank AND rods.

 

Well not having the injectors and the TB are going to hurt power and not really help fuel milage.... as the boys said wrong hobby if you care about fuel milage.

Care to elaborate.... i'd rather have a 4340 forging, with bushed pin bores and ARP bolts, rather than fix a stock rod to do the same thing.

I know how you like that forgien stuff ;-)

Bret

 

lets drop the fuel mileage thing, i got a 9 sec mustang at home that gets about 2 miles to the gallon on c12 so i'm just looking for a quick streetable car not a 11 sec camaro getting honda gas mileage. Thats not important i just want to make sure my shorty combo will handle what i want to do.

 

save your money and use the stock rods. 95+ powdered metal rods are probably the best thing chevy came up with for the LT1.

 

True they are good rods.... but to get them up to the level of the aftermarket rods is going to cost you the same money and you are left with a weaker rod.

Bret