Hemis and NHRA

[426 Hemi]

I was wondering if a hemi pro stock motor can succesfully be boosted. i was advised by a well known shop that the hemi99 is not a good cantidate for blown applications due to parts breakage. What do you guys think?

[moeflo]

Originally Posted by 426 Hemi

I was wondering if a hemi pro stock motor can succesfully be boosted. i was advised by a well known shop that the hemi99 is not a good cantidate for blown applications due to parts breakage. What do you guys think?

I don't know. I haven't heard anything about them having any parts breakage problems. If it's something related to boost, well, I've never seen/heard of one boosted. Has it been done?

[426 Hemi]

Originally Posted by moeflo

I don't know. I haven't heard anything about them having any parts breakage problems. If it's something related to boost, well, I've never seen/heard of one boosted. Has it been done?

I've never seen it done, but I'm curious about the possibilties. Could you "detune" it with a smaller cam and lower CR and then boost it to get the HP back up to 1300 or maybe even close to 2000 HP?

[speedexx]

Originally Posted by 426 Hemi

Could you "detune" it with a smaller cam and lower CR and then boost it to get the HP back up to 1300 or maybe even close to 2000 HP?

Should work doing what you described above. Getting to 1300 or so should be pretty easy (depending on gas used). On alky, 2,000 ought to be possible. There's some blown chev wedge headed engines on alky out there making around 3,000 - so why not?

[426 Hemi]

Originally Posted by speedexx

Should work doing what you described above. Getting to 1300 or so should be pretty easy (depending on gas used). On alky, 2,000 ought to be possible. There's some blown chev wedge headed engines on alky out there making around 3,000 - so why not?

Maybe the guy thought I wanted to have it set on "kill", he said once I started to get around 2000 hp it would start "hurting itself". Actually, I was wondering more about detuning it, so I can get some use out of the motor. I know it would'nt like the low CR with the huge ports, so thought "why not boost it " either with turbo or centrifugal blower to make the motor "happy" again.

[moeflo]

It sounds like the guy you're talking with has some experience with '99's on boost. I'd like to hear him elaborate on what concerns him about that motor. It looks like a state of the art race motor from all angles to me. But, being a P/S piece, some stuff may be prepped wrong for big boost. Like rod journal diameters????Are yours 1.88" for instance? The "super-lightweight" pro stock details probably aren't the best way to build blower motor. You're looking at less RPM. So, boosting it back to 13-1400 HP will require you to make more power per per revolution than a pro stock motor at 10K. It's a different kind of stress. It's why I don't build motors.

[Maxwedge]

addendum
the new challenger doesnt have a IRS...its a solid axel. The New Camaro has an IRS tho

[426 Hemi]

Originally Posted by moeflo

It sounds like the guy you're talking with has some experience with '99's on boost. I'd like to hear him elaborate on what concerns him about that motor. It looks like a state of the art race motor from all angles to me. But, being a P/S piece, some stuff may be prepped wrong for big boost. Like rod journal diameters????Are yours 1.88" for instance? The "super-lightweight" pro stock details probably aren't the best way to build blower motor. You're looking at less RPM. So, boosting it back to 13-1400 HP will require you to make more power per per revolution than a pro stock motor at 10K. It's a different kind of stress. It's why I don't build motors.

he did'nt elaborate much, but yes I believe his premise was that the "light weight P/S parts" would not hold up under alot of boost. My rod journals are 2.000. The bottom end sure looks beefy enough, the block is the high nickel iron, wonder where the "weak link" could be? The crank is'nt that light either, imo. I was like you, figuring this is an ultra performance motor and should take some abuse..but..i dunno.

[426 Hemi]

Heres the whole email he sent me:

hello dave,
the Hemi 99 engines are built for one thing, nhra pro stock. they are strong, dont get me wrong but they are not designed to be put in a boosted application. depending on how light some of the parts are in it, i would guess at 1600 to 1800 hp the engine would start to hurt its self. if you are looking to make something like 2000hp to 3000hp + the BAE engine would be a ton more reliable and easier to get parts for.


Thank you for the opportunity to earn your business.

Kind Regards,


CJ Heskett

SMRE Performance
1590 Creston St.
Muskegon, MI 49442
Phone: 231-773-8150
Fax: 231-767-0483
Email: cj@smreperformance.com
Web: www.

[426 Hemi]

Thanks guys. As time goes on I will try to post what i end up doing.

addendum(thanks max)
Just got this reply today, after I explained my goals better to them...

david
yes, changing those things, ( cam, intake, compression) and adding turbos with low boost and make 1000 to 1400 hp will be easy. you could do it on pump gas or even e-85. the thing will drive fairly nice and look way cool in a street car. till you whacked the go peddle then hold on. and it would live a very long and happy life. going over 1800hp because of the LW components in the engine, will lower the reliability a ton. we would love to work with you on a project like this. please give me a call if we can help.


Thank you for the opportunity to earn your business.

Kind Regards,


CJ Heskett

SMRE Performance
1590 Creston St.
Muskegon, MI 49442
Phone: 231-773-8150
Fax: 231-767-0483
Email: cj@smreperformance.com
Web: www.smreperformance.com

[speedexx]

Moeflo, from what you've seen & read about the new pro stock "ford Hemi" what's the difference from it and the Mopar '99 Hemi? I don't know about the valve angles & clocking, but otherwise it looks like a dead ringer to me.
Do you see any real differences??

No small wonder Morgan immediately abandoned the Mopar ship to go to ford. I suspect he'll have it running & qualifying pretty quick, since he'll be working with basically the same casting it appears to me.

[23T-Wedge]

Originally Posted by 426 Hemi

he did'nt elaborate much, but yes I believe his premise was that the "light weight P/S parts" would not hold up under alot of boost. My rod journals are 2.000. The bottom end sure looks beefy enough, the block is the high nickel iron, wonder where the "weak link" could be? The crank is'nt that light either, imo. I was like you, figuring this is an ultra performance motor and should take some abuse..but..i dunno.

Think the biggest issue is whether the parts will hold up the first time you hit the detonation button (I know there is one there because someone always hits it...) having heavier components just gives you a built-in cushion, (just like the aluminum rod/shock absorber analogy). 2.00" journals might be fine for a 370" small block putting out 12-1300hp, but I don't think I would trust them on a blown 500". The P/S pistons I'm sure are the lightest pin possible, skirts probably close to non-existent, and thinnest low-tension rings possible. With a perfect world blown alky tune-up right off the bat, this stuff will hold up for a while, but there isn't much of a window if you miss it. Just as an FYI, I just bought a set of Arias b/a pistons and pins, the last set came with .187" taper wall pins, personally havn't had any problems, but apparently they've had enough customers that did, so they now only make a
.250" (yes .250") wall pin, sob weighs close to 275 grams, didn't have time to re-balance assy before last race so I put my old 215 gram pins back in. Only real point to that is to say "Light-weight" and "blower motors" don't mix.