996TT head work? - Page 2 - 6SpeedOnline - Porsche Forum and Luxury Car Resource

Dec 23, 2014 | 05:58 PM

#16

pwdrhound

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Quote:

Originally Posted by Wealth Manager

The 997 INTAKE lifters are the newest GEN's that everyone should change to.

The 996 Exhaust lifters are still a separate part number then the 997 version.

That's right. The latest lifters are 996.105.255.25 intake (997version) and 996.105.041.72 exhaust. It was actually the exhaust that failed on me but I replaces all of them.

https://www.6speedonline.com/forums/...ve-lifter.html

Dec 23, 2014 | 06:35 PM

#17

Wealth Manager

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Quote:

Originally Posted by pwdrhound

Wish there was just a solid aftermarket replacement that was long term reliable. Rev it up really high without the need for a rebuild so often.

Maximize the gt35's for some of the big guys and make the car even more track friendly for the road course racers like yourself.

Dec 23, 2014 | 07:09 PM

#18

heavychevy

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Quote:

Originally Posted by pwdrhound

This is not some off the chart mega hp built. The goal of the rebuild is a reliable road course motor 3.8 motor that I can run in the 550-580whp range on modest boost on 91/100 octane mix. Car will see almost 100% track duty. It is actually very similar to what GMG did engine wise a while back in this thread:

https://www.6speedonline.com/forums/...onversion.html

Nothing fancy but I would like to have good throttle response the a reliable 7500 redline for added flexibility. Hence my questions re the valve train. My car currently runs a 7200 redline on stock heads. If it's a question of a light port job and lighter valve train for a reasonable amount of money to go to 7500, I'd be game. Having the ability to sometimes delay that extra mid turn shift that a higher redline allows is nice. I am not doing any regrind cams or any of that stuff. Again, keeping it simple. Initially I thought a GT3 exhaust cam may offer benefit but it doesn't seem there is any benefit there either.

I'll be interested in following your progress as I'm gonna open mine up sometime in the next couple of years and that 7500 rpm sounds tasty.

Dec 24, 2014 | 10:48 AM

#19

pwdrhound

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Quote:

Originally Posted by Willy077

What about http://www.ng-motorsports.de someone tried them?

This kind of porting would be optimal. For best flow you actually do not want a smooth port but a uniform rough one instead to energize the boundary layer of air in turn increasing flow. The golf ball finish might be ideal. Too bad the guys that do this are in Germany. I'm not sure if anyone stateside does anything like this.

Last edited by pwdrhound; Dec 24, 2014 at 03:27 PM.

Dec 24, 2014 | 12:28 PM

#20

BLKMGK

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That's some pretty amazing work!

Dec 24, 2014 | 02:14 PM

#21

mrmaass

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Quote:

Originally Posted by Willy077

What about http://www.ng-motorsports.de someone tried them?

*drools on screen*
That is a work of art!

Dec 25, 2014 | 04:09 PM

#22

pwdrhound

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Another question. Probably a long shot but does anyone have the weights of the OEM intake and exhaust valves?

Dec 25, 2014 | 07:00 PM

#23

pwdrhound

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Quote:

Originally Posted by WOODTSTER

McKinzie is the 996TT head master.
Todd at Protomotive could hook you up

Is this the guy? Todd McKenzie?

http://mckenzie-s-racing-cylinder-heads.hub.biz

Last edited by pwdrhound; Dec 26, 2014 at 11:08 AM.

Dec 26, 2014 | 03:25 PM

#24

Warehouse33

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pwdrhound,

I have new genuine Porsche 996tt intake & exhaust valves on my desk that I can weigh later this evening at home for you if you would like? My shipping scale here at work doesn't even recognize they're on the scale.

-Jason

Dec 26, 2014 | 05:00 PM

#25

pwdrhound

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Quote:

Originally Posted by Warehouse33

That would be great Jason. Thank you very much. Obviously scale calibration plays a big part here. Weighing a single valve may be tough as they are very light. Might be best to weigh all 12 exhaust valves together and divide the weight by 12 to get a more accurate individual number. Same with the intake valves. Thanks again!

Dec 26, 2014 | 09:54 PM

#26

Warehouse33

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996-105-111-72 Intake Valve 62 grams
996-105-113-72 Exhaust Valve 50 grams

-Jason

Sep 21, 2015 | 12:35 PM

#27

Thunder915

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Which shop offer clean up job for reasonable pricing ?

Sep 21, 2015 | 12:52 PM

#28

pwdrhound

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Quote:

Originally Posted by Thunder915

Which shop offer clean up job for reasonable pricing ?

Todd McKenzie did mine..

Sep 22, 2015 | 03:14 PM

#29

G-Rat

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Quote:

Originally Posted by pwdrhound

I already have the latest 997 exhaust/intake lifters in my car. Did that 2 years ago when my stock ones failed.

Excuse my ignorance but I'm curious, what was involved in replacing the lifters? I'm guessing that its an engine out ordeal right? I think that I may have a sticky lifter issue but I'm wondering if it is worth it to fix or wait for a full engine build.