Intake base and head mismatch
Thread Starter
Race Director
Joined: Jun 2004
Posts: 13,922
Likes: 700
From: WI
Intake base and head mismatch
I took a picture down the port of a big mouth base on a stock head.
I measured the head at 30 MM for port width, and the intake is also at 30 MM. So if you use a large base it port matches pretty well.
I measured the head at 30 MM for port width, and the intake is also at 30 MM. So if you use a large base it port matches pretty well.
Thread Starter
Race Director
Joined: Jun 2004
Posts: 13,922
Likes: 700
From: WI
I'm putting in some ported heads. 
And a super ram! 
Just about ready to lift off the drivers head, not bad for an evenings work.
I had the large base on the stock untouched heads for awhile and wondered what it looked like in there. Finally got a chance to take a pic!
And a super ram! Just about ready to lift off the drivers head, not bad for an evenings work.
I had the large base on the stock untouched heads for awhile and wondered what it looked like in there. Finally got a chance to take a pic!
Race Director
Joined: Nov 2003
Posts: 12,220
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
I can't tell for sure in your pics....Are you showing that the ports didn't line up? I've read this as being a problem with some HSRs but hadn't heard it about TPI bases (large/not).
Race Director
Joined: Apr 2003
Posts: 17,694
Likes: 1,666
From: moraga ca
Thread Starter
Race Director
Joined: Jun 2004
Posts: 13,922
Likes: 700
From: WI
Hmmmmm....Your title says mismatch but you say it matches pretty well. Theoretically, it should match up since they're both 1204 ports.
I can't tell for sure in your pics....Are you showing that the ports didn't line up? I've read this as being a problem with some HSRs but hadn't heard it about TPI bases (large/not).
I can't tell for sure in your pics....Are you showing that the ports didn't line up? I've read this as being a problem with some HSRs but hadn't heard it about TPI bases (large/not).
Now I have heads ported to 1205 so I'll have to work on the base a little. Looks like it needs 2 MM extra width. My 1205 gasket set measures 32 MM.
I can't wait to try out this new setup! Ported 113's, 1.6 rockers, and a ported SR. I'm somewhat agonized over not changing the cam and being right there. Since I'm changing the timing chain, while I'm there changing the dampener.
A cam change will put up a class with the Z06 though for my race classing.
Team Owner
Joined: Dec 2007
Posts: 20,974
Likes: 261
Thread Starter
Race Director
Joined: Jun 2004
Posts: 13,922
Likes: 700
From: WI
I posted more pix in the dampener thread I started.
http://forums.corvetteforum.com/c4-t...dampeners.html
http://forums.corvetteforum.com/c4-t...dampeners.html
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
