8k rpm ...

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toolmanmike said:
There's a recipe in there but it's hard to sort out of the conversation.
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I would have had it done a piece at the time. It's complex and long but a little here and a little there will get it done. Maybe Karl will do it.
 
brian6pac said:
O.K. My 340 I built in 1977 and on a major budget just out of high school. I had been collecting 340 parts and had a lot of low mileage parts. I had a perfect std bore 69 block, a perfect crank, and with the help of a friend that was a engineer at Chrysler and a racer I put together a nice 340. It had full groove clevite micro babbit mains, micro babbit rod bearings, stock crank, my buddy did the rods opened up the big end so it would have .0035 clearance then cut .001 off the caps, we had .0025 top to bottom on the rod and .0035 on the sides. Now you can just buy bearings with more side clearance but not back then. 10.5 :1 pistons std bore, 400 grit finish, moly rings .040 + 5 file fit Chevy rings, 1/3 the price of mopar rings. X heads pocket ported with a full radius seats, my buddy made his own stones on a fixture he made at Chrysler. Stock 2.02 1.60 valves, dual valve springs, MP cam .572 .296 mechanical with crane ductile rockers, Hooker 1 7/8 super comp headers, MP mechanical 6 pack carbs. Ran 11.84 114.9 MPH in a 64 Barracuda shifting at 7600 RPM
727 Turbo Action VB, 4200 stall TA converter, 5:13 Dana 60 w/spool

View attachment 1715428025

View attachment 1715428026
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These pictures are from 1980 - 81 era
 
With the right intake parts you can get one to rpm to 8000 and it will sound amazing! right up until it goes BOOM! When things go bad at that rpm, you might be able to reuse the spark plug wires. Stock block equals Cap walk, bore wall instability. If you want RPM go R5/P7.
 
I want to make it clear I not trying to discourage the OP from doing what he wants.

I'm trying to open his eyes to what he is really wanting to do.

Again, it's not a small block Chevy. Not only is the oil timing off, the valve train geometry is junk, on both sides of the rocker arm.
And if he doesn't address those issues, he will burn through his money so fast he'll be bankrupt so fast he won't know how it happened. Unless he is incredibly wealthy, and even then it's still a HUGE expense and a vertical learning curve.

If he's will to spend the money on a Ritter block which has the oil timing corrected, and get the lifter bank angle down to 48 degrees, and use a head that has valve gear capable of that RPM (and it ain't using stands with saddles in them) then I say go for it.

If he's not willing to do that, then he needs to reconsider his options. Like build 400 inches and turn it 7000 and make sure he does it with 340 mains and go smoke some ricers and Chevy junk.
 
yellow rose said:
I want to make it clear I not trying to discourage the OP from doing what he wants.

I'm trying to open his eyes to what he is really wanting to do.

Again, it's not a small block Chevy. Not only is the oil timing off, the valve train geometry is junk, on both sides of the rocker arm.
And if he doesn't address those issues, he will burn through his money so fast he'll be bankrupt so fast he won't know how it happened. Unless he is incredibly wealthy, and even then it's still a HUGE expense and a vertical learning curve.

If he's will to spend the money on a Ritter block which has the oil timing corrected, and get the lifter bank angle down to 48 degrees, and use a head that has valve gear capable of that RPM (and it ain't using stands with saddles in them) then I say go for it.

If he's not willing to do that, then he needs to reconsider his options. Like build 400 inches and turn it 7000 and make sure he does it with 340 mains and go smoke some ricers and Chevy junk.
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No discouragement taken, that's why I posted this ! In my mind it sounds awesome, reality is another thing.
Maybe I'll just stroke the 71 340 block I have, put the eddy rpm heads that are currently on my #'s engine and see where that gets me .... I'm sure plenty to have fun ! Also keep it running on 93 octane
 
65-440 said:
No discouragement taken, that's why I posted this ! In my mind it sounds awesome, reality is another thing.
Maybe I'll just stroke the 71 340 block I have, put the eddy rpm heads that are currently on my #'s engine and see where that gets me .... I'm sure plenty to have fun ! Also keep it running on 93 octane
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And then go out an ROACH your buddy with his 327 and his junk Sun II tach that is wrong!!! That'll wad his panties.
 
Most true! ^^^^^^^

Stroke the 340 and make peak power a lot lower in the RPM range. This equals longevity as it is not taxing the engine through RPM’s out the WaZoo!

A powerful stroker needs good heads (carb & intake) to feed it. I’d rather make 550 hp at 6 or 6.5 than 8K RPM any day of the week.
 
I shifted my 422 at 7000 rpm and ran 9.42 in the 1/4 and 5.97-6.0’s in the 1/8 for 3 years. I pushed it another year so I lowered my rpm down to 6700 and ran 6.0’s. Hmmmmm
 
65-440 said:
Don't have a number in mind honestly, just want it to hold together !
This all stems from a guy near me with a 327/4spd 55 Chevy. He drives the **** out of his car, shifts at 8k everytime he drives it. Sounds amazing!
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Can you clear your inbox out, or call me?
 
65-440 said:
Ok, don't beat me up on this one. No I don't race, I know it's completely impractical .... thinking of rebuilding the engine in my 70 340 swinger in the near future. Will be putting the #'s matching engine in the corner of the garage, I have a complete stock bore 71 340 that I'd build. My problem, I want 8k rpm. Want to build a fun, high revving engine for around town pleasure. Not sure why 8k stands out to me but it just does . My question is, how attainable is this and how much work are we talking about so I don't worry about sending shrapnel outside the engine block everytime I get on it ?
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8k is a lofty goal. Be prepared to spend some $$ developing it. As in build it test it-only to find that combo A didn't work. Build combo B and test it only to find that didn't work either, onto Combo C etc....

Most posters here seem to think a 5500 rpm stroker is the hot ticket. My advice would be to seek out a different forum for this kind of advice--think ST here.

Valve train aside for a moment , take a look at the piston speed.

I've attached a file that shows it will take a 3.31 crank until 8500 rpm to match the piston speed of a 4" stroke @ 7000 rpm. I like to use Eagle Specialty's calculators, they are a lot of fun and easy. So to summarize a 340's piston will reach a piston speed of 122.8 FPS (feet/sec) @ 8500 rpm vs a 408's piston speed of 122.2 FPS @ 7000 rpm. Good luck, J.Rob
 
Moving the powerband up a few hundred from stock (idle-5000) can start to make your car less street able. That’s why the factory keep on building bigger displacements to reach power goals instead of spinning a smaller engine higher.

Every 500 rpm you move up from stock is huge power difference and cost to a build, for a pure street car you really don’t want to go above a peak power rpm of 5500.

5500 rpm is a lot of rpm for a street car and can make serious power especially 400 cid plus.

Plus to make power up around 8000 rpm your gonna need 350+ cfm heads.

If all you want is rpm maybe go with smaller displacement like a 273 needs a lot less head flow to reach high rpms, especially if you can find a 2.96 crank (248 cid) or a 170 /6 :)
 
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65-440 said:
Ok, don't beat me up on this one. No I don't race, I know it's completely impractical .... thinking of rebuilding the engine in my 70 340 swinger in the near future. Will be putting the #'s matching engine in the corner of the garage, I have a complete stock bore 71 340 that I'd build. My problem, I want 8k rpm. Want to build a fun, high revving engine for around town pleasure. Not sure why 8k stands out to me but it just does . My question is, how attainable is this and how much work are we talking about so I don't worry about sending shrapnel outside the engine block everytime I get on it ?
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No I don't race. you answered the question yourself. It is not practical to build an 8000 rpm 340 street motor.
The cylinder head and camshaft needed to make power at 8000rpm makes it a RACE motor.
Why build a sewing machine for the street. That's a Chevy small block thing.
6800 -7000rpm 340 will be more than enough for the street and monetarily and practical to build.
 
We just ran into the same question. The guy has the money and for some reason wants to turn 8K in a street car.

I asked him hiw often do you race?

Never, i just want a fast streer car that sounds like this.
Pulls up a you tube video of a race car doing burn outs at about 5K? On the street.

I ask, how often do you think you will be able to hit 8K on public roads?

Well when ever i want right?

Me.... uh no.... at 8K you will be breaking the law in first gear....

For some reason he is stuck on this magical 8k number so i sent him to talk to my engine builder (who is not cheep) and i haven't herd back yet....

:rofl:
 
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