Interesting comment..

[charlief1]

One of the posters in that thread (Erland Cox) said that in his opinion quench was fine up to about 15 psi boost but over 20 psi you needed to get rid of it or it would cause detonation. That puts almost all of us into the no quench group . No one else commented on that (so far), and Darin hasn't personally posted in the thread.

Well I did ask some questions and one of them directed me to some good info about the "singh grooves" which has led me to do a little reading on detonation. The board has some really good info on detonation and it's causes.:smile:

 

[Jerryl]

Well I did ask some questions and one of them directed me to some good info about the "singh grooves" which has led me to do a little reading on detonation. The board has some really good info on detonation and it's causes.:smile:

Hey Charlie,
Did you forget about this one? :tongue:
http://www.turbobuick.com/forums/engine-tech/207484-cylinder-head-grooves.html

 

[charlief1]

Didn't forget about it Jerryl, but wanted more info on it.

 

[Mike T]

on the Speedtalk engine forum, regarding turbo head design...
"Do these heads almost like you would do a set for a normally aspirated combination except,

(1) make the intake and exhaust seats .055 wide. Use 45° seat angles (wider seats will lower valve operating temp.)
(2) Intake throat at 90%
(3) Exhaust throat at 90%. Need to keep the exhaust throat this size for two reasons. The seat ring footing on the register needs to be strong and if your running a nail head Inconel (which you should) it will breath better.
(4) Do a "soft" chamber. In a turbo engine you want ZERO quench. The chamber must be total soft with no squish/quench anywhere in sight.
(5) Do not run a dish piston if you can help it. In high boost application it will pop the top of the piston right off. Putt all the volume in the chamber and piston to head clearance.

A link to the thread.. [requires registering to get into the advanced engine forum.]
http://speedtalk.com/forum/viewtopic.php?f=15&t=28450&start=15

Chuck I know this was from a while ago but thanks for the link. I'm very interested in this subject and a search only brought up two threads discussing head softening.
I did my chambers as described in your post about 10 years ago. Signed up for speedtalk last night and it takes 12 hours to access the first time.

Surprising how little we discuss out of the box ideas on here.

 

[Chuck Leeper]

Surprising how little we discuss out of the box ideas on here.

U R right, Mike. dealing w/ 30+ y/o designs makes it almost a necessity. Also, these obsolete/no longer used designs, low production/survivor cars don't promote much inincentive to come w/ modern replacement. Cams are, and a couple aftermkt heads, is about it.

 

[Mike T]

Chuck thanks for prompting me to join. Speedtalk has came up in other google searches but you needed to be a member to view so I put it off. Read the entire thread and found it to be very interesting. Especially interesting because my heads are near quenchless with seemingly no downside.

 

[dank GN]

When I received all my indy stuff . The pistons they ran in there turbo program is pretty interesting as it is a flat top with acouple valve reliefs . So I take it they wanted as much meat on the piston . Running methanol how hard is it to get into detonation ?