930 valves in a 951 8v head ?
Thread Starter
Rennlist Member
Joined: Mar 2004
Posts: 428
Likes: 0
From: France
930 valves in a 951 8v head ?
Hi,
I've searched about this question but didn't manage to find dataes about the following question.
Can 930 valves (which are bigger and cheaper than 2.7 valves) can be installed in a 951 head ? Is there room enough in the head to be removed to fit them ?
TIA
Marc.
I've searched about this question but didn't manage to find dataes about the following question.
Can 930 valves (which are bigger and cheaper than 2.7 valves) can be installed in a 951 head ? Is there room enough in the head to be removed to fit them ?
TIA
Marc.
Former Vendor
Joined: Mar 2002
Posts: 6,885
Likes: 39
From: Atlanta
The 930 valves are not the same length as the 944/951 valves (I think they are a bit shorter). You can use Chevy valves, but they are not 9mm so guides, retainers and keepers etc.. must be changed as well. We use custom 9mm large valves that are not the stock 2.7L valves. I agree, 2.7L valves are a bit pricey.
Three Wheelin'
Joined: Jul 2005
Posts: 1,635
Likes: 20
From: Estonia
And using 9mm valves is pointless as those valves are heavy like a anchors. 7mm stem is fine and thinner stem serves two purposes: less resistance to air movement (=better flow) and lighter valvetrain (=you don't need killer valver springs).
Three Wheelin'
Joined: Sep 2005
Posts: 1,965
Likes: 0
From: Tulsa Oklahoma
Nothing wrong with stiffening the valve springs. The valves don't weigh in at 10 pounds or anything... Plus, not like the 951 is a high strung motor. Has a relatively low redline compared to other 4cyls.
Trending Topics
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
Genius Porsche-Themed Gifts That'll Make Any Dad or Grad Smile
Joe Kucinski
10 Used Porsches Are Selling for Way Too Cheap
Joe Kucinski
Tuner Is Converting Porsche 911s Into Shooting Brakes
Verdad Gallardo
This Coachbuilt Creation Is A Modern Take on the Legendary Porsche 917
Verdad Gallardo
Is This Convertible Cayenne A Steal, Or A Returnless Investment?
Verdad Gallardo
10 Best Non-Flat Six Porsches You Can Buy For Under $100K
Joe Kucinski
Porsche's Top 5 Most Questionable Naming Decisions
Verdad Gallardo
Pogea Racing's 964 Porsche 911 Reimagination Stands Out in a Crowded Field
Verdad Gallardo
6 Convertible Top MYTHS Most People Don't Understand!
Michael S. Palmer
Three Wheelin'
Joined: Jul 2006
Posts: 1,583
Likes: 2
From: Weehawken NJ
This is a great idea, I guess the hardest part would be to find the valve guides and machine the retainer to hold the valve keepers. Was it very difficult?
Drifting
Joined: Apr 2004
Posts: 2,969
Likes: 2
From: Tucson AZ, Dallas Tx sometimes
So what is the size of the valve head for those big block valves? Anyone have a part number?
Also what kind of benifit do you get from the large valves? I dont want to lose all the low and mid range torque due to slow intake air velocity.
Also what kind of benifit do you get from the large valves? I dont want to lose all the low and mid range torque due to slow intake air velocity.
