Rotating assembly

[68camaroguy]

im building a 355 sbc. i gotta good block. i need a good rotating assembly. i wanna go all forged. whats better H-Beam rods or I-Beam rods??????? i have no clue motors gunna make about 450hp 490lbs ft. when complete

[unstable bob gable]

For a long time the "H" configuration was considered to be the choice for max effort engines, but by the nature of their design they can be heavier than an "I" beam rod. For the power level that you are looking to achieve either style rod would be fine. There are many choices available for a recip. assy. It really comes down to how much money you want to spend. A lot of the cheaper parts are made and machined over seas. Or made overseas and machined here. If you want quality 4340 steel American made parts it is going to cost you more than the over seas/off brand stuff. So, I'd check the budget, and see what you are willing to spend.

[1984camaroz28]

i use eagle alot in the lower budget builds good parts never had any brake yet

[68camaroguy]

thanx guys i have about $1300 to spend on a on the rotating assembly and i wanna go all forged so i can later supercharge. any ideas or suggestions??

[Pampered-Z]

More info on the engine type and SC please. What type of blower and how much power?

The thing to keep in mind that with a SC you are placing stress on the crank snout, if you're talking about a small centrifical blower or small roots blower for a few pounds of boost a midrange crank would be fine, if your talking about a roots style 6-71 type blower and hanging a 3" belt pulley off the end of the crank then I would go with a even higher quality unit.

Also keep in mind that for a blower with over 6-7 PSI you may want to look at dished pistons to drop compression and as such piston and ring selection could change.

For 500 HP you could use a stock steel crank or the eagle products are fine for ( my unprofessional view ) 600-700HP, if you plan to go higher boost or more HP, then I would look more at the Lunati or Callie, but you may quickly go over your budget. I use the Callie's light weight stealth crank (stroker not stock throw) and it cost almost you budget alone.

Tell us more so we can spend your money!

[68camaroguy]

ok so ive been chattin with the guy whos helpin me with the build and we decided to go N/A.. im gunna build a 377 with 450-500 hp. the block is a 1-pc RMS 4 bolt roller block. i know im gunna be needing a stroker set up i just dont know which yet. im gunna use a hi-lift hydraulic roller cam with around a 240-248 duration and 1.65 roller rockers. ported and polished heads about 70cc chambers(i think) roller lifters. edelbrock performer rpm airgap, holley 650 dbl pumper. no choke. full msd ignition hooker 1 3/4 headers turbo 350 with shift kit and converter and 3.73:1 posi rear. should make decent power right??? anyway the rotating assembly is all in question??? what NEEDS to be forged, what doesnt?? lookin for some advice. hope thats enough info

[Tru2Chevy]

Never seen a stroker kit for a 350 block that will give you 377". That's normally a 400 block, .030 over, with a 350 crank in it.

- Justin

[68camaroguy]

i dunno thats what my engine guy said. and im pretty sure that south state speed shop builds fresh 377 outta 350s. i could be mistaken though

[WildBillyT]

Originally Posted by Tru2Chevy

Never seen a stroker kit for a 350 block that will give you 377". That's normally a 400 block, .030 over, with a 350 crank in it.

- Justin

Yeah, I have seen the same. It's a 350 stroke with a 400 bore to get 377.

[bubba428]

377 can also be a 350 block with the stock 4.000in bore and a 3.75in stroke

[WildBillyT]

Originally Posted by bubba428

377 can also be a 350 block with the stock 4.000in bore and a 3.75in stroke

It is rare to see this though. Only when you can keep a 350 block standard bore. Most of the time you at least go .030 over.

[68camaroguy]

well i have a standard bore 350, would it HAVE to be bored over, or could it just be cleaned up and used to go 377

[WildBillyT]

Originally Posted by 68camaroguy

well i have a standard bore 350, would it HAVE to be bored over, or could it just be cleaned up and used to go 377

Might just be able to be honed. It really depends on what the machine shop says.

[johnjzjz]

you cant make a 350 block a 377 you are mistaken in the buy off the shelf world -- any thing can be done with money is no object --

350 block parts availability 362 350 crank off set ground .100 to make 3 - 9/16 stroke we did that 35 years ago and parts are still out their -- second a 400 crank in a 350 block is the 383 stroker probly what they were talking about not a 377 yet the 377 motor is way more powerful and long lasting but as was said the 377 has a 400 block bore and a 350 crank the opposite of what you have -- go with a 383 cheap re sizing for the money and free power you cant get from a 350 -- jz

[Featherburner]

Originally Posted by johnjzjz

you cant make a 350 block a 377 you are mistaken in the buy off the shelf world -- any thing can be done with money is no object --

jz

How many cubic inches is a 4" bore and a 3.75" stroke?

[johnjzjz]

the slide ruel sayes around 377 correct - i stand corrected - i have never taken a block from a customer and not pareled decked the top and squaired the bore to the crank, too correct all of what is not right with a production core -- not making excuses its just not done buy me in my shop - 4.030 bore and the 400 stroke crank makes a 383 -- i guess the glass of italian ink was better than usual -- i was not thinking back yard building again i stand corrected -- jz

[WildBillyT]

John,

Correct me if I'm wrong, but if somebody were to build a 377 with a 350 block and 400 crank they would have to use different pistons than they did with the 350, and these pistons would have to be "custom" since they have to work with a 4" bore and 3.75" stroke. Most off the shelf parts are made to build 383s using a 4.030 bore, which keeps the price down.

Right?

[johnjzjz]

bill you are right on the target - the off the shelf supply is the place the deals are because of the supply that is available is on hand -- its also in my opinion a bad combo i never liked it -- and the reason is< first and YES again the compression height < location of rist pin from top of piston is much closer to the top on a 383 motor with 5.7 rod < stock length < and thats what i dont like about the combo it loads the cylinder wall if you use a 6 inch rod or even better a 6.125 rod its better but piston size is an issue for street use to me maybe not others -- the angle of the rod as it turns in the block with the 4 inch bore has a different load effect than a 4,125 bore of a 406 motor its a math thing called ( rod stroke ratio ) some see it this way and some dont i could fill a 40 yard dumpster with the motors that came from other places that dident work it taught us what not to do if you know what i mean -- i am not sure why he dont just build a 9.1/2 maybe a bit more to one 383 steel crank i beam bushed rods KB pistons are light not the best but LW tool steel LW pins a set of alloy heads 195 CC ports 525 lift HYD cam make it bumpy a 650 DP with a msd 6 al w/ the rpm chip and blaster coil / wires high pressure oil pump not high volume/pressure, coated cam bearings and spec out the rods and mains to .002 and .003 on the crank small front LW balancer maybe alloy type, 3 speed trans or 700 type 355 diff it will be in the high 11s and he wont need a bar and can use OEM belts -- just my opinion -- jz

[68camaroguy]

ok so maybe ill just go with the 355