Hey guys,

first off, i've been reading on this forum for quite a while and now finally signed up, so let me say hello and thanks for all the info i've found here in the past years

right now i'm looking for a new powerplant to build up for my 89 formula which currently has a somewhat modded 305 in it. it's my summerday weekend baby, i sometimes drive it to work as well.

anyways, i would love to have something different from a 350 and the 383 is too torquey at all for me, so i'd like to have something along the lines of a high-revving 302, 327 or if need be a stout built 350 that will also take some rev's here and there. the 305 is probably not an option for me due to the restricted bore.. i'm looking for at least 400-500fwhp btw, but i'd be content with 400whp depending on rpm and torque.

so i was looking at the 302 build people are doing utilizing the 3" stroke crank from the GenII baby-LT1 'L99'. staying 1pc rear main seal would save me a coupe hundreds of bucks because i have a T56 that will be going in that car (2pc rms fw and clutch setup are big $$), plus i also think the 1pc rms is more leak-resistant.

so here goes my question, don't beat on me if this is the total bullsh*t, but i thought it'd be worth a shot to go and ask

is there any way to build a 1pc rms 327?

imho there would be two options:
1) have a custom 3.25" stroke 1pc rms crank built (prolly major $$)
2) take a L99 3" stroke crank (any forged cranks available?) and stick it into a 350 block. okay now we would have a 302 with a 1pc rms. now add a set of random 6.125" rods ... and some 350 pistons that were made for 6.0" rods. with a compression height of 1.260" that would mean the stroke is now adjusted to 3.25" that's with a 0.015" piston-to-deck clearance.

what do you guys think?

thanks for your time,
greetz

You are making a lot of work for yourself to destroke an engine. Don't be so concerned on making a shorter stroke engine. Invest your money into a good set of heads. Heads is were the power is.

At least build a 350. A 350 with good rod bolts, a big cam, and good heads will rev up to 7000+ very quickly. And make more hp and torque over the smaller 302 or 327.

I have a 362 cid (slightly bored and stroked 350) and it revs to 7200 very fast. Valve float is what limits the rpm. 11:1 cr with 200cc dart heads and a compcam 292H.

And there is no reason a 383 will not rev to 7000+ rpm.

If you want power, then build a big engine.

a 406 would be even better! Add big heads and big cam and rev it up.

Uh, sorry but you can't "adjust" the stroke by changing rods. You still would have a 3" stroke regardless of rod length.

have you thought about an all roller motor. a 350 bored .30 over to 355 with an all roller valve train would be high reving, fast reving motor. If you took the cr up to like 10:1 or 11:1 like 454C10 said, that would be a motor along the lines of what your looking for.

Okay, i know you guys are right and that the stroke doesn't matter all that much in order to make high-rev power.. with a 3.48" i could still rev 7k and barely surpass a mean piston speed of 4k fpm. anyways, in whatever engine i plan on running ~10-11 CR on this build due to long rods and relatively big cam on a hydraulic (?) roller valvetrain. depending on dynamic compression, maybe more? just for the info, i'm going to run at least 91 octane, flattops and i'm at about 700 ft altitude. i'm also aware that money on heads and valvetrain is prolly the best spent in an engine of this type.

still i was wondering if there was some way to.. well, i'll say 'adjust' again due to the absence of a better word for it.. adjust the stroke. i know it sounds stupid, but after all, the effective stroke is piston travel from BDC to TDC, right? which, based on my calculating would be 3.25" because of the long rods and the longer compression height pistons? plus there could be rod/block clearance or piston skirt issues that i'm not aware of, so i thought i'll just throw it out there

thanks for your input so far!
greetz janus

nobody on my stroke calculations? come on, help a newbie prove himself wrong lol.

the stroke of the crank is the stroke of the engine. no rod changes can effective the stroke. however, using less stroke and a longer rod is possible. Then adjust the piston pin height to get the correct deck height. I think this is what you are say? custom cranks and custom pistons to destroke and long rod is money not well spent for a street engine with no engine size limit (this isn't nascar).

Plus, making a smaller engine is going backwards in hp. long rods sound cool but not worth the gains (if any). longer stroke and good heads give much better returns.

do a web search on long rod engines, and most professional race engine builders will say adding long rods doesn't do much (especially on a street/strip engine).

i understand that the crank stroke is not effected. what i'm trying to say is that in the combination i stated, the piston would travel the same distance as in a 3.25" stroke 327 engine with stock rods and pistons. although dead center piston dwell would probably be longer than with stock rods. dunno if that makes it easier to understand what i've been thinking of.. it would make the effective stroke, as in distance of piston travel from BDC to TDC, the same as in a 327 - NOT crank stroke.

btw, custom pistons or rods would not be needed for this. 3" crank from the destroked LT1, 6.125 rods and 350 pistons with 1.260" compression height. i wouldn't exactly call those parts 'custom'.

i think i've understood it's not practical to build such an engine. i would still like to keep up the discussion for theoretical purposes though. thanks again

The piston travel would NOT be the same as a 327, the crank throw is the only thing that affects the stroke, what rod you put in there does not affect that. It does however affect piston acceleration and velocity. The dwell time would be much greater with a 3" stroke and a 6.125" rod as opposed to a 3.25" stroke and a 5.7" rod, the real question is, "do you want more or less dwell time?"

The enign eyou outlined is very practical to build, the real question is what application would it be best suited to?

a piston could travel 3.25 inches with a 3 inch stoke crank but could do that only once.

I just thought about this thing some more and spent some time with calculating and thinking again. Daaaaaamn came across that you're right! that was easy. of course piston travel is ONLY affected by stroke - because between TDC and BDC, the only difference is the stroke that is added or subtracted in the equation of piston position in the bore. now that i recognize that, i realize how easy and clear it is. i must have been having some kind of blocking that out in my previous thinking.

finally proved wrong. thanks

edit: 454C10, lol that's funny

I just had a 327 built recently. It dyno'd out at 408.5 HP@5200 RPM and peak torque was 423.9@4800 RPM. The bore is 4.03, 9.5/1 compression, -8 Brodix heads with 2.02 valves, 210 runners, Comp cam .477/.480 lift, 224/231 duration@.050, ProComp single plane intake and it runs on pump gas. I put it in my 1978 Corvette. Power and gas mileage is a lot better than my stock 350 CID motor.

Sounds like a nice setup. That setup will do well with a 2600-2800 stall and 3.55 to 3.73 gears (hope you changed the stock stall and gears).

I would expect the power to be much better than a stock 78 350 with that build. However, if you would had build a 350 the same way you would had made more about 7% more power. (437hp and 454 ftlbs). And a 400 cid would had made close to 500hp.

wow that's really good torque out of a hyd cam'd 327, nice

I realize the same build would have been better with a 350 or 400 setup. Except I didn't have the block for a 400, which are not easy to come by with out shelling out extra cash, nor the bottom end to make it a 350. I came by the parts for the 327 when I got a 68 corvette with an extra engine block and low end. So instead of getting new low end parts I decided to use what I already had which was the 327 low end and have less parts laying around. And I like the nostalgia of the 327, with the technology blend of today.

As far as stall and gears, my car has the stock 3:55 rear end and I put in a 2300-2700 stall torque converter. A March serpentine kit also mounts the front of the engine which is powdered coated in Chevy orange. After this has been done all I now like is a paint job to complete my 78 Vette project.