My new 340 at the track

[Newbomb Turk]

I get it, but your car is 2700 pounds. That makes a huge difference.
Like I said, stick a stroker crank in it, would be way faster and run even less rpm. Your car runs great, but you can’t argue more inches won’t make it faster, that is all I am saying.

I argue this all the time. It’s just not even worth it any more.

Stoke doesn’t make power. Power IS rpm. Arguing that is foolish.

It’s now 2025 (because PBR is so excited to get to Christmas I’m going right through new years) and valve train is so much better than it ever was.

If he puts a striker crank in it all it will do is make more torque below peak and reduce rpm.

Seriously, on Chrysler oiling and a 59 degree LBA you can easily, easily turn 7500 and not hurt parts.

Given the same engine, one with let’s say a 3.79 stroke verses the much loved 4 inch stroke, even that little bit of extra stroke requires more cylinder head and induction to keep peak torque and power at the same rpm.

And I won’t even get into how the dyno can lie to you.

RPM is power. I can never see reducing rpm making sense. It just doesn’t.

It affects the chassis too.

 

[ValiantRacing]

I argue this all the time. It’s just not even worth it any more.

Stoke doesn’t make power. Power IS rpm. Arguing that is foolish.

It’s now 2025 (because PBR is so excited to get to Christmas I’m going right through new years) and valve train is so much better than it ever was.

If he puts a striker crank in it all it will do is make more torque below peak and reduce rpm.

Seriously, on Chrysler oiling and a 59 degree LBA you can easily, easily turn 7500 and not hurt parts.

Given the same engine, one with let’s say a 3.79 stroke verses the much loved 4 inch stroke, even that little bit of extra stroke requires more cylinder head and induction to keep peak torque and power at the same rpm.

And I won’t even get into how the dyno can lie to you.

RPM is power. I can never see reducing rpm making sense. It just doesn’t.

It affects the chassis too.

I prefer not to run a 4 inch crank in any engine i build, for me or my daughter, i do like RPMs, my engine does not sound like its working that hard at 7500 plus.

 

[pittsburghracer]

I have a very nice stock crank 360 shortblock I built a couple of years ago that I built for my son to get back out. I bought everything from a Moparts member. He joined here shortly after but I Dont know if he comes on here anymore. Originally I bought the Crower rods, stock 360 crank cut down to Chevy size, very nice oil pan he built, pistons, etc then he offered me the bushed block so
I made another road trip. It included a nice .660 lift roller cam and used Crower lifters. I’m sure it would be the 9’s somewhere with my Edelbrock heads but the crank being cut to Chevy size kinda scares me. Curiosity may force me to try it someday.

 

[Newbomb Turk]

I have a very nice stock crank 360 shortblock I built a couple of years ago that I built for my son to get back out. I bought everything from a Moparts member. He joined here shortly after but I Dont know if he comes on here anymore. Originally I bought the Crower rods, stock 360 crank cut down to Chevy size, very nice oil pan he built, pistons, etc then he offered me the bushed block so
I made another road trip. It included a nice .660 lift roller cam and used Crower lifters. I’m sure it would be the 9’s somewhere with my Edelbrock heads but the crank being cut to Chevy size kinda scares me. Curiosity may force me to try it someday.

I’ve cut many cranks down to SBC LJ crank size. I’ve had a few turned to SBC SJ size if it was an aluminum rod build.

I turned every BBM crank down to 2.200 (BBC) because unless it’s got a blower on it they are too big. And it needs to be over 4k hp because AFAIK no one uses anything other than 2.200 rod throws on anything.

If I didn’t already have rods I’d turn my crank to 2.100. I’ve run my personal stuff at .030 Chrysler size which is .005 under Chevy stuff and beat the crap out of them.

I’d run that crank so fast my shorts would have to catch up.

 

[pittsburghracer]

I’ve cut many cranks down to SBC LJ crank size. I’ve had a few turned to SBC SJ size if it was an aluminum rod build.

I turned every BBM crank down to 2.200 (BBC) because unless it’s got a blower on it they are too big. And it needs to be over 4k hp because AFAIK no one uses anything other than 2.200 rod throws on anything.

If I didn’t already have rods I’d turn my crank to 2.100. I’ve run my personal stuff at .030 Chrysler size which is .005 under Chevy stuff and beat the crap out of them.

I’d run that crank so fast my shorts would have to catch up.

A few pictures I found. He did a lot Of nice work on the oiling system.

 

[Newbomb Turk]

A few pictures I found. He did a lot Of nice work on the oiling system.

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Looking at the block picture can you tell me where he’s getting the oil to the rocker feed galleries? I can’t see where he picked it up and I’m assuming it’s not pushrod oiling.

Edit: I see what he’s doing and I think that’s a damn good way to do it.

I have started doing something similar to stop pulling oil off the feed to the mains to feed the heads.

 

[pittsburghracer]

Looking at the block picture can you tell me where he’s getting the oil to the rocket feed galleries? I can’t see where he picked it up and I’m assuming it’s not pushrod oiling.

Edit: I see what he’s doing and I think that’s a damn good way to do it.

I have started doing something similar to stop pulling oil off the feed to the mains to feed the heads.

Thanks for figuring it out because I’m pretty tight lipped on HIS mods. As they are his mods. He did a lot of different things from top to bottom. So the stock crank cut down to Chevy size wouldn’t bother you running in the 9’s. Remembering that I run all 1/8th mile except on a test n tune night if I want a 1/4 mile number.

 

[Newbomb Turk]

Thanks for figuring it out because I’m pretty tight lipped on HIS mods. As they are his mods. He did a lot of different things from top to bottom. So the stock crank cut down to Chevy size wouldn’t bother you running in the 9’s. Remembering that I run all 1/8th mile except on a test n tune night if I want a 1/4 mile number.

Wouldn’t bother me at all. The one thing that would concern me with a cast crank is if they turned the mains down to 340 size. That would get me a bit nervous.

Saying that, it’s internally balanced and to me that’s a big deal. Getting the balance forces off the ends of the crank makes them live longer.

Yup, I’d run that and not lose a wink of sleep.

Maybe tomorrow if I get out to the shop I’ll take some pictures of what I’m doing. It’s very close to what he did.

Or maybe a video. I hate typing.

 

[273]

Don't they usually add fillet radius when turning down to help with strength ?

 

[Newbomb Turk]

Don't they usually add fillet radius when turning down to help with strength ?

I can’t remember if going to 2.100 takes enough off to get rid of the rolled filets on those cranks. I’m pretty sure going to 2 inch throws does. Like 99.9% sure.

I will say I’ve never broken a Chrysler crank with a rolled filet. That’s actually a very good way to do it.

 

[dusterbing the peace]

The engine isn’t together yet, so I can’t speak from experience at this time, but I had mine turned down to 2.100 as well. Being a worry wort, I had it re-nitrited. My reasoning was to run the lighter weight Eagle (Chevy) rods, with the smaller diameter 927 wrist pins to reduce stresses due to weight on the reciprocating assembly. Topped it off with lightweight flat tops (435 grams) and 1/1/2mm ring pack. Again, all in the name of reducing the reciprocating weight to reduce stresses and deflection since I plan to turn up to around 8k. Bob weight came out to 1,580. All that being said, I fully support turning down to the Chevy rod journal, but am of course heavily biased in my opinion

Sorry to derail, the 340 in this thread is killer and I’m super jealous!!!

 

[cli55er]

My 408 stroker dynoed at 592hp and 577trq. 11:1 compression. Hydraulic roller, duration @ .050: 252/258 lift: .620"/.620" 110 LSA On 93 Pump gas. Idles at about 80kpa at 950rpm so I’m interested in the breather to collector connections like the OP has vs my catch can to the efi.

In a 70 Dart…..3000 stall… 3.73 rear gears… 727….cooper cobra radial street tires…. Open diff… (lame)

12.2@114… couldn’t get traction to save my life off the line. Easily a second wasted there. Efi tune wasn’t working to my advantage either.

slicks and a suregrip and a better efi tune…I’m sure I could get into the 10s, but I’m def jealous of the OP track time and cubes to power. That motor sounds nice! Mine is also done racing…. It was a one time deal and it’s a street car now.