Stroked vs Bored

[ruckdr]

Joe117,
Yes, these things are quit accurate (were), not sure what NHRA is using now, maybe the same thing. As I recall (30 years ago), we removed the rocker arms (both valves closed), and a one way valve in the tube, allowed the equalization of air to be "sucked" in as the piston goes down, and pushed out as the piston goes up. It was a hassel to do this, and we were only CCed when we set a national record (a few times through the 1970's), and sometimes when we won a major race.
Later,

 

[joe117]

Yes, removing the rockers and using a valve in the device would do it.

Even though a tool like that exists, I still think it a long shot that someone would go to the trouble of doing the displacement measurement on a car they were buying to prove it was a stock stroke.

I could see someone perhaps doing the measurement to ensure that a claimed stroker was actually that.

The guy had said he was worried about being able to return the engine to stock stroke.
I still think that this is not something he needs to be concerned about.

 

[GTS Bruce]

Anything is possible if you have enough money.Me?I'm a NA guy and will go with handlig up grades first,brakes second and motor last.I like to drive and am not a point a squirt guy. Bruce

 

[Big Medicine]

This 30 thousandths max bore spec, where does it come from? Manufacturer?

 

[Torquemonster]

This 30 thousandths max bore spec, where does it come from? Manufacturer?

Just look at a block.

You can bore it out 0.100" but you'll have smoke coming out your exhaust pipes in no time.

You need a certain amount of metal between bores to not only stop cracking, but also to keep the bores straight and round. If you go too thin you can't have straight/round bores - and that means loss of power at best, and eventually much worse.

 

[LTHL VPR]

Re-sleeving the engine will take care of overbore concerns. This is not that difficult to do and will make the engine last for many, many miles (with the right sleeves). We did this on my 750hp NA motor just as added precaution since Car and Driver test drives and customer demo rides are ******* the car....

 

[Torquemonster]

Lethal is 100% correct - the problem is that a lot of machine shops are just way out of their league on this stuff.... it is simple enough, but pick your machine shop VERY CAREFULLY...

I've been UNimpressed with a lot of machine work i have seen here... it seems like any job that is not routine, or that requires some trouble or great precison - it throws them...

no slur on the good ones - there are some exceptional people in the trade... but like rocking chair poop and chicken lips - they are rare

well maybe not as rare as chicken lips...

I'll say this for free - if you handed a blueprint spec for a shortblock and asked the machine shop to sign off on each clearance and tolerance - THEN had them double checked by someone independent - you'd quickly find the men from the cowboys.... and a sad procession of wanna be's you would find.

this free commentary was brought to you today by the John Kerry "buy American products no matter how bad they are" campaign...

and don't hit me - I'm just having fun some fo the best machining in the world is done here... just not down at Freds Grease Pit and Bore Bar

 

[Big Medicine]

This 30 thousandths max bore spec, where does it come from? Manufacturer?

Just look at a block.

You can bore it out 0.100" but you'll have smoke coming out your exhaust pipes in no time.

You need a certain amount of metal between bores to not only stop cracking, but also to keep the bores straight and round. If you go too thin you can't have straight/round bores - and that means loss of power at best, and eventually much worse.

Right, I understand, so....... where soes this spec come from?

 

[Big Medicine]

Lethal is 100% correct - the problem is that a lot of machine shops are just way out of their league on this stuff.... it is simple enough, but pick your machine shop VERY CAREFULLY...

I've been UNimpressed with a lot of machine work i have seen here... it seems like any job that is not routine, or that requires some trouble or great precison - it throws them...

no slur on the good ones - there are some exceptional people in the trade... but like rocking chair poop and chicken lips - they are rare

well maybe not as rare as chicken lips...

I'll say this for free - if you handed a blueprint spec for a shortblock and asked the machine shop to sign off on each clearance and tolerance - THEN had them double checked by someone independent - you'd quickly find the men from the cowboys.... and a sad procession of wanna be's you would find.

this free commentary was brought to you today by the John Kerry "buy American products no matter how bad they are" campaign...

and don't hit me - I'm just having fun some fo the best machining in the world is done here... just not down at Freds Grease Pit and Bore Bar

I agree wholeheartedly; do it for a living (separating fact from fiction) on old industrial engines & compressors, 500,000 hp fleet of reciprocating integral & centrifugal separables.

 

[joe117]

"reciprocating integral & centrifugal separables"

That sounds like a very cool thing.

What is it?

 

[CHAD]

Sounds like compressed air.

 

[Big Medicine]

Interstate natural gas transmission compression. Cooper Bessemers, Clark, & Ingersoll Rand turbocharged, 2 stroke & 4 stroke reciprocating engines with double acting compressors mounted to the side of the crankcase, connecting rods to the crank. Centrifugal compressors are General Electric & Solar turbines driving a separate compressor mechanism through a load coupling.

e.g. Cooper Bessemer Z-330 rated at 12,300 hp at 330 rpm, 20 articulated power piston rods, 20-inch bore, 20-inch stroke. Master rods on the compressors. Prefer constant torque, variable speed operations.

Old, neat stuff that no one makes parts for.

 

[Torquemonster]

wow - 20" x 20" bore and stroke - THAT is a real mountain motor

let's see...

12,300hp @ 330rpm is how much torque?

12300 x 5252 = 64599600 / 330 = 195,756 ft / lb of torque!!

 

[joe117]

And if you had one in your Viper you would be thinking of how best to mod it for REAL power.

 

[Torquemonster]

And if you had one in your Viper you would be thinking of how best to mod it for REAL power.

mmmm... let's see

if we prepared the 20" bores to straight and round within 0.0002" under operating stresses, lightened the reciprocating mass by 25% by using higher tech/strength forgings and precision balanced them within 0.5 gram of each other, obtained special rings that were prepared flat and perfectly round, then tightened the quench clearance to 0.010" - then port matched the beast, with a bit of port and bowl work, back-cutting the valves and giving it a 3 angle valve job, then add a little fuel by increasing the pressure and open up the air inlet - hey - we should be able to see 25,000hp at a still conservative 660rpm.... hey we'd even through in some ceramic coatings and teflon piston skirt coatings!

 

[GTS Bruce]

Not true.My brother in law at Ingersol Rand engineers them.Yep you can get parts bearings etc..You pay,they design,service,build,design.. Bruce

 

[DLTARNU]

Most of the 542s make anywhere between 550 and 650 rwhp depending on CR, head flow characteristics, cam, etc.

Heffner has a 510 Stroker package that puts out 700HP. Don't know if that is at the crank or the flywheel. Flying Dutchman had it done on his '99 GTS. Maybe he can chime in with the specs of the package?

 

[Big Medicine]

Not true.My brother in law at Ingersol Rand engineers them.Yep you can get parts bearings etc..You pay,they design,service,build,design.. Bruce

Good, ask him to e-mail me or the DRESSER-RAND Houston office because I need a about 10 heads for a KVS clean burn conversion. They can't seem to figure anything out down here. I'd also be interseted to know if he has any contacts for a spare Cooper Bessemer V250 crank.

 

[Anthony - 98 GTS]

Most of the 542s make anywhere between 550 and 650 rwhp depending on CR, head flow characteristics, cam, etc.

Heffner has a 510 Stroker package that puts out 700HP. Don't know if that is at the crank or the flywheel. Flying Dutchman had it done on his '99 GTS. Maybe he can chime in with the specs of the package?

I'm making almost 750 HP at the crank on my 510 stroker. Although mine is not exactly a "mild" tune.

 

[DLTARNU]

What all was done to your car to make 750HP?

 

[Big Medicine]

Bueller? Bueller? Bueller? Bueller? Bueller? Bueller? Bueller? Bueller? Bueller? Bueller? Bueller? Bueller? Bueller? Bueller? Bueller? Bueller?

 

[Anthony - 98 GTS]

What all was done to your car to make 750HP?

510 stroker, CNC heads, custom cam, solid roller, increased compression, 70mm throttle bodies, carbon fiber air intake, full exhaust, no cats. That's about it.