PONTIAC ZONE TECH FORUMS
 

Go Back   PONTIAC ZONE TECH FORUMS >
Engine Tech
> Tiger Head
User Name
Password

Tiger Head Tiger Head owners can give there opinions along with their track results

sponser links

Reply
 
Thread Tools
Old 11-05-09, 04:29PM   #16
Big Speed
Registered User
 
Big Speed's Avatar
 
Join Date: Apr 2008
Location: Paterson New Jersey
Posts: 124
Default

O.K. , I guess we're all on the same page now . From DCI's original design...we moved the intake guide .050" toward cylinder center back in 2006 or so. Since then , there have been a handfull of sets that had the guide moved an ADDITIONAL .050". A few sets went to Bischoff and we have a couple of sets that are yet untouched...except R&D. We have several R&D heads with valve guides in different postitions , both intake and exhaust. None of which have made it to a running engine...YET. The catalog heads were the first priority. Frank has been wanting to race what he sells to any customer, so we had to concentrate on that first. Yor right John...Rex's current heads needed the valve guide moved...it was supposed to be done...but was'nt. Real strong mid-lift when we moved the valve again! We were supposed to try these on Frank's new dry sump engine...but who knows.
Samples I have here flow about 470-480. Cheers , Johnny
__________________
Checkered Flag Machine & Ceralli Competition Engines
Competition engines , Induction development & 5-axis CNC porting
http://www.checkeredflagmachine.net/
Big Speed is offline   Reply With Quote
Old 11-05-09, 04:37PM   #17
John Langer
Drag Racer
 
Join Date: Dec 2005
Location: philadelphia pa
Posts: 99
Default

I was wrong on the year, the heads that I got back in the fall of 2006 had the valve in the stock location. I moved them .100. We were able to get 480cfm out of them with KILLER mid range numbers. The exhaust are what they are. These were the heads that the "new head" valve spacing was modeled after.
John Langer is offline   Reply With Quote
Old 11-05-09, 04:45PM   #18
EC
Registered User
 
EC's Avatar
 
Join Date: Aug 2002
Location: naperville Il
Posts: 1,946
Default

So why arent the heads offered with the .100 offset to begin with. I dont see what the down side would be. Just make all the heads with the guide moved to that position. Why offer the head with the guides in a less desirable position and make the end user move it?
EC is offline   Reply With Quote
Old 11-05-09, 04:45PM   #19
EC
Registered User
 
EC's Avatar
 
Join Date: Aug 2002
Location: naperville Il
Posts: 1,946
Default

John are you willing to post what those heads flowed at .500 lift?
EC is offline   Reply With Quote
Old 11-05-09, 04:49PM   #20
John Langer
Drag Racer
 
Join Date: Dec 2005
Location: philadelphia pa
Posts: 99
Default

Quote:
Originally Posted by EC View Post
John are you willing to post what those heads flowed at .500 lift?
if memory is correct, they were atleast 420cfm.
John Langer is offline   Reply With Quote
Old 11-05-09, 04:52PM   #21
John Langer
Drag Racer
 
Join Date: Dec 2005
Location: philadelphia pa
Posts: 99
Default

Quote:
Originally Posted by EC View Post
So why arent the heads offered with the .100 offset to begin with. I dont see what the down side would be. Just make all the heads with the guide moved to that position. Why offer the head with the guides in a less desirable position and make the end user move it?
The heads weren't originally designed to have the valve where I put it. I moved the intake valve to get it away from the cylinder wall and reduced the exhaust valve size. You need ALOT of cam to make it work. It is not practical for the average user. The only other person that has my valve configuration is Rex.
John Langer is offline   Reply With Quote
Old 11-05-09, 10:45PM   #22
Big Speed
Registered User
 
Big Speed's Avatar
 
Join Date: Apr 2008
Location: Paterson New Jersey
Posts: 124
Default

Quote:
Originally Posted by John Langer
The heads weren't originally designed to have the valve where I put it. I moved the intake valve to get it away from the cylinder wall and reduced the exhaust valve size. You need ALOT of cam to make it work. It is not practical for the average user. The only other person that has my valve configuration is Rex.
That's right John , we owned castings already at the time and the machining requires...well...special attention. It is sort of application specific to position the valves like this for a couple of reasons , like John said in it's current configuration , it ends up being not practical for the average user.

EC , I would'nt exactly call it "less desireable" in it's current position...they still support well over 1,000 h.p. . But the changes...that's what we're calling "Tiger 2" .
__________________
Checkered Flag Machine & Ceralli Competition Engines
Competition engines , Induction development & 5-axis CNC porting
http://www.checkeredflagmachine.net/
Big Speed is offline   Reply With Quote
Old 11-05-09, 11:55PM   #23
464GP69
Registered User
 
464GP69's Avatar
 
Join Date: Mar 2008
Location: tigard or
Posts: 1,254
Default

Quote:
Originally Posted by John Langer View Post
if memory is correct, they were atleast 420cfm.
DAMN! Movin some air there Guy!
__________________
DSRE Your Newest NW Pontiac Race Engine Builder, Specializing in Hi HP Pump Gas Pontiacs and FE Fords
464GP69 is offline   Reply With Quote
Old 11-21-09, 02:09AM   #24
twinturrbo406
Pontiholic
 
Join Date: Aug 2008
Location: ocoee florida
Posts: 726
Default Velocity Readings ??

Did you have any velocity readings on those ports John ?? What was the Volume and average CSA ? What did they flow at .300 ?? What exh./int. ratio did you end up with ?? How much Compression ??
twinturrbo406 is offline   Reply With Quote
Old 11-21-09, 04:41PM   #25
EC
Registered User
 
EC's Avatar
 
Join Date: Aug 2002
Location: naperville Il
Posts: 1,946
Default

Who cares about ex/in ratio? That doesn't mean anything.
__________________
Baddest pump gas engine around!!!
EC is offline   Reply With Quote
Old 11-21-09, 06:36PM   #26
twinturrbo406
Pontiholic
 
Join Date: Aug 2008
Location: ocoee florida
Posts: 726
Default Really ??

Well, EC, that was a real informative post. Thank you for the helpful statement. I would be willing to bet, that if you were to try and run Langers exhaust/int ratio, on say ...... a moderate C.I. blown pump gas motor, with a streetable Hyd. Rllr, in a 3,500+lb car, i think you'd find that your statement couldn't be more incorrect.
But what do i know ??
twinturrbo406 is offline   Reply With Quote
Old 11-21-09, 06:52PM   #27
EC
Registered User
 
EC's Avatar
 
Join Date: Aug 2002
Location: naperville Il
Posts: 1,946
Default

Where did the blown pump gas motor come from? My point was I believe most head ports get what they can out of the intake. Then they do what they can with the exhaust. I have heard that the sound of the exhaust port on the flow bench and the shape of the port is more important than the flow numbers. But I could be wrong. I know if you look at my ex/in ratio it is something like 63%
__________________
Baddest pump gas engine around!!!
EC is offline   Reply With Quote
Old 11-21-09, 08:22PM   #28
twinturrbo406
Pontiholic
 
Join Date: Aug 2008
Location: ocoee florida
Posts: 726
Default Where ??

Where did it come from ?? Well, it was based on what you said "Who cares about ex/in ratio? That doesn't mean anything" .... all i did, was simply give you a quick example as to how in-accurate that statement was.
You didn't make mention of what you thought about exh. port shapes, and or port sounds while flow testing, you simply said....... " Who cares about ex/in ratio? That doesn't mean anything ...." Where i live, exh/int means alot when dealing with pump gas motors, you having one, i would think you'd know that. Just my 2 cents.
twinturrbo406 is offline   Reply With Quote
Old 11-21-09, 08:30PM   #29
EC
Registered User
 
EC's Avatar
 
Join Date: Aug 2002
Location: naperville Il
Posts: 1,946
Default

Why does pump gas make the ratio more important?
__________________
Baddest pump gas engine around!!!
EC is offline   Reply With Quote
Old 11-21-09, 08:36PM   #30
twinturrbo406
Pontiholic
 
Join Date: Aug 2008
Location: ocoee florida
Posts: 726
Default Help .....

Well, basically, a compression motor can tolerate less exh/int ratio because of the improvements from the high compression and the effects that has on cumbustion. Which aids in the blowdown event. Basically. Pump gas fuel is really crappy stuff, it needs alot of help to get things done. Like your wonderful set of cylinder heads that you have for one.
twinturrbo406 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Port Volumes vs. cfm Gach Engine Tech Discussion - Street or Strip 128 01-27-10 11:26AM
Aftermarket Cylinder head stack ranking discussion Bruce Wilkie Engine Tech Discussion - Street or Strip 119 12-15-08 12:51PM
DCI Tiger Heads, good news Gach Aftermarket News & Products 7 07-02-05 02:54PM


All times are GMT -3. The time now is 04:10AM.

Featured Ads
Ken's Speed & Machine
Mayhem Turbocharging

Carter Cryogenics.  What can we freeze for you?

Pacific Performance Racing

Central Virginia Machine Service.  Home of the Injun Engine!

All Pontiac Engine Kits

Larry's Auto Machine.  Full serivce auto, marine machine shop, domestic and foreign.

Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
2001 - 2007 PontiacZone.com
Page generated in 0.11246 seconds with 43 queries