I was wondering what the cons are of running a 500 CI Hemi 99?
Is the maintenance really that bad or can you get 100 passes out of one before a rebuild?
Throwing this out there to see if it's worth the coin to spend on one.
It will be going in a 68 barracuda.

Just from the little I have read they go through valve springs like gasoline. But damn they are cool!

Couple guys on here run them....


Couple for sale as well:
http://www.racingjunk.com/Drag-Racing/2171537/500-CI-NHRA-Pro-Stock-Hemi.html

http://www.racingjunk.com/Door-Cars/181870959/-969-Hemi-Dart.html

The second one isn't a Hemi 99. Still one bad dude , but gen. II in that car.

Ooops....now I am baffled. In car is a 99 , but the motor in the others pics isn't. 538 inches tells me maybe not a 99 , but the text doesn't specify.

You can build a 538 cube Hemi99,just put some arm in it. Bryant will grind up anything u want. The 426 style motor looks like it has old alky or fuel heads on it.

I'm betting Al would sell you his 99 Hemi...... and even comes with a nicely equipped 68 Barracuda!

That Dart is a steal !

When did Stanfield do Mopar? I thought he was always a Chevy guy. Is that an engine development program for someone else or did he start on a Mopar and quit before it got on the track?

Danny

How is valve geometry ?
what else is there to look for?

They spin them close to 11,000 RPM so I'm sure the valve train geometry is really really good.
500CID 1400HP what's not to like.
Valve train maintainance will cost you an arm and a leg.

Thanks guys, I guess senility is creeping up on me, I don't remember that at all.

Danny

IIRC, Stanfield ran a Dodge in 2001 or 2002. I think he ran Nickens power.I have some pics around here, I see if I can find them. The car was flat black as I recall. Seems that he ran pretty well with it.

Paul

I have no direct experience but I can give you what I know from reading I've done and people I've spoken with.

First, the valvetrain like is mostly dependent upon rpm and depending on which version of hemi99 you get, there varying degrees of "good" with the valvetrain. There are two different rocker stands, a two and four bolts with the four bolt being the better of the two. This was to deal with the higher spring pressures. The other thing that I've heard is that this motor is peaky when setup like the pro stocks to run at maximum rpms leaving a very fine tuning window if you were looking for max performance.

In regards to spring life, barring no over revs, a friend of mine that worked with a well known Comp Eliminator engine builders race car told me they went the entire season(40-50runs) without changing a spring in a motor that crossed the line at 10k. What typically happens is that more people err on the side of caution and change springs more often than necessary in motors spinning that type rpm. Once the 10k line is crossed however, spring life decreases significantly.

If you had and unlimited budget, I believe the best way to make an engine like this more friendly would be to order a custom tall deck block like what Rick Corn has done so you can stroke the motor and decrease the rpm range. Of course you would have to massage the combo to get it right but it would be a good strategy to increase spring life. Those are the things I've read about the most that come to mind, I know there are also a few different blocks out as well with and w/o skirts as well as varying numbers of cam bearings.

100 passes on a rebuild not even maybe and when ours is runnin good we usually take out a valve spring every third pass

It has to revolve a lot around how many RPM and the camshaft used.
I see a lot of Big Chief BBC's with longer and more angled pushrods than 99's in fast bracket cars. The springs are checked regularly but milder cams allow some mileage from their springs. As soon as they find themselves in a max-effort class where they are spun near the limit like P/S, they eat springs with the best of them.