What is the highest max RPM on your 2 bolt smallblock? We were running 7,250 with 305 and 6,750 with 350. Both had cast cranks, stock rods (ARP bolts) and cast pistons. When they were torn down for inspection, everything was fine.

 

Unless you have a lot of boost from a power adder, 2 bolt blocks are fine. If in doubt, install some ARP studs.

It's always good practice to get proper parts and machine work. If the block has been line honed and the rotating assembly is balanced, it will have no problems.

I'd upgrade from the cast pistons though. They're heavy and weak.

 

Inspect the pin area of those pistons after every season.

 

I am also interested in this question. What needs to be done to keep a stock 305 together over 6000 rpm in a road racing situation? Will an aftermarket balancer be enough? Will the rotating assembly need to be balanced? What valve springs should be used?

 

In the process of upgrading 350 engine right now. Boosted compression w/hypereutectic pistons, solid cam, good rods and sfi damper and flexplate. Had in excess of 300 passes and bearings and cylinder walls look great.

Also adding single plane manifold and matching ports to pro heads.

When complete, will have 12.7 - 1 CR, .040" quench clearance. Should help drop 60' times from current 1.56.

Additional: When we ran the 305, Junior miscalculated with rev limiter and tried spinning motor to 7500 - 7750 range. No power made but it sounded nice. Espicially on the burnout in 2nd gear. When it was taken out in favor of 350, the engine looked fine. No sign of wear.

I think part of the equation is the high volume oil pump. We run a high volume pump with light synthetic oil.

 

what are/were your bearing clearances?...thats some crazy rpm

 

I've regularily run my Hill Climb\Autocross motor past 6,500 rpm with no problems with the two bolt block or with the stock cast crank.

When running Hill Climbs or track days ( Road Race ) I generally shift between 6,200 to 6,500. Rev limiter is set at 7,000 and I will occassionally have to run the engine up against the limiter to avoid a shift before a corner. This engine has been in car for 5 years with only one freshen ( bearings and rings needed ). Came out perfect. Note: I used to run engine higher ( 6,500 to 7,000 shift point ) but found I was beyond power range of combo. Dropped RPM shift point and picked up time

Cast crank is not a problem. Drag racing you could probably run 7,000 all year as long as you did not run Nitrous or forced induction. That require a forged crank. Good Rods, ARP rod bolts, ARP main studs, balancer ( Fluid Damper recommended ) are a must. Piston weight also critical. The lighter the better.

I have a two bolt main, Late style block with. Spent many hours detailing block, relieving stress areas with grinding ( particularily around webs ), relieving oil pump passage area. Many hours detailing wide body " X" rods....polished, radiused bolt flats, shot peened and ARP bolts of course. Keith Black Signature series pistons.

If I did it all again I would have no problems using a two bolt block. But I would use ARP main studs instead of ARP main bolts, Aftermarket rods ( They are getting so cheap now that it's not worth my time and effort to detail stock rods ) probably Scat H-Beam or Crower Rods and a set of Ross lightweight forged pistons. Ross pistons ar very high quality, reasonably priced and they are light.

Nice thing about a cast crank is that it is light. As long as you do not run extended high rpm's ( Road Racing ) or Nitrous\Blower a cast crank should be fine. Forged would be good...but some of the cheaper ones are heavy. Important to check the weight of forged crank.

 

A lightweight crank sounds nice but I'm not sure how heavy it will get after balancing. My current buildup is using JE race pistons (not the cheaper, heavier SRP ones) and some Howard aluminum rods. Because the pistons and rods are so light, mallory weight needs to be added to the crank to get everything balanced. The crank is a 4340 Eagle steel crank.

The engine I spun a main braring in had the same crank and pistons but had Scat I beam rods. Mallory weight still had to be added to the crank.

High rpm, 6500+, you should invest in lightweight internal parts and ARP everything. Although you can away without doing this, you increase the life expectance of the parts if you do. Don't expect the "cast" pistons to last very long at those high rpms. Those pistons are extremely heavy. I did 2 years with my old 383 stroker spinning it to 7000 rpm before a cast piston blew apart and totaled the engine. Either that or a rod bolt let go. From all the damage it was hard to tell what failed first.

At 7500+ rpm, start looking at titanium valve train parts if you want them to last.

 

Mine makes trips up to 6500+ rpm with no problems. Using an early 90's 2 bolt main block, GM steel crank with extra machine work done to it, ARP main studs, Eagle H-beam rods, Wiseco forged pistons and a fluid damper which has all been ballanced. It's been almost a year since getting it running and have had only the stock ignition go out on me as far as problems. Picked up a lot of top end switching to all MSD stuff.

 

Have engine together with new parts. Got rained out last Wed. night. Hurricane Frances eliminated this weekend. Will run next Friday night if Ivan stays out of way.

Son is bouncing off walls because we have not gotten a pass in yet. Car sounds strong, additional compression is very apparent.

Last setup was flattop pistons (4 VR) 230 dur./.465 lift hydraulic and 750 dp on dual plane. (180 PSI cranking Comp.)

New setup is .120" dome speed pro coated pistons, 248 I-251 E dur./.533 I-.542 E lift solid cam and 750 DP on victor type single plane. (210-215 PSI cranking Comp.)

 

My 383 stroker in the nova takes trips to 10k every race! all forged bottom its a 4340 Steal race kit... my tach is correct and the car pulls all the way to 10.5 in first second it goes to 10 and in 3rd it redlines at 9k this motor is outrageous! My 2 bolt in the monte carlo takes visits to 7k in first second and third

 

Have you got a video of the Nova? I wanna hear that thing turn 10,000 rpm

 

Me too. Even a 302 road race SBC only peaks out in the 8000 - 8200 range. About the only V8 you'd hear getting close to 10k would be a Comp Eliminator engine and that's because they use a lot of titanium parts to help keep them together.

I don't think your tach is very accurate.

 

10,000rpm 383? Lemme hear it!!! Always thought a SBC spinning to 7,000-7,500 was reving pretty damn high.

What did you build it with to withstand 10k?

 

I think it's time to put down the crack pipe.


BTW, how much intake dur. at .050 would it take to actually allow a motor to spin that high under it's own power?

 

That Might just be the case! its a AutoMeter Recall tach and i dont know how reliable they are so i cant tell ya! but it shure does sound like a 10krpm i raced a new cobra with the pullie chip tries fullexaust and a cold air intake and such and the car was so loud i couldnt even hear his car!

 

You guys don't drive these cars on the street, do you?

How many miles to you get before you rebuild?

Thanks,
Jason

 

i dive the monte carlo everyday and the nova when ever im not in the monte carlo

 

Consider that Nextel cup cars are pulling a maximum of 9,700 to 9,800 in Road Race trim....with 355CI and a Stroke of 3.10" or less then and super trick, hugely expensive valve trains. I highly, highly doubt that your street driven 383 with a 3.75" stroke is going to pull 10,000 RPM.

Either your tach is wrong or you're just spouting

 

Its not necessarily bull****, but probably is. Thegeneral had a 73 camaro that would spin 9k all day. granted it was as built as a 350 can get, but still retained stock stroke. To say that it cant spin that high is kinda in itself. To say it doesnt spin that high is probably true

 

Might want to check that little switch on the back of the tack to make sure it isn't in the "4cyl" or "6cyl" position...

 

Do you people call bs on everything? My pop had a 327 outa a 67 vette he built it up and it ran 10k all day long. i got my tach checked by my buddy ( a mechanic) said the tach was 1000 rpm off. so 9k thats not that far off man just like you said the genral did it so why is bs when i do it?

 

1000 RPMs off at what reading?

In my younger days, I had a "screaming" 302 SBC but no tach. I was sure it must be turning over 7000 RPMs at my by-ear shift points based on what I read in the magazines. When I did finally hook a tach up to it, I found out it was actually falling over on its face at 6000 RPMs (weak points ignition).

Keeping a 383 together that regularly sees 10000 RPM is probably a $30k or so investment. Not a whole lot less for a 327.

We don't "call bs on everything", just the more obvious.