rags

Too much work for me! If by chance I am able to run more boost after the mod, I'll just chalk it up to my "modified" head. If I get nothing, off it comes and the old unmodified chamber head goes back on. Either way I'll let the list know. For my sanity I hope I don't see any benefit.

This question is for John. When doing a comparison, what would you say is an acceptable boost increase that would be attainable from the loss of compression due to the grooves? If chamber cc increase is necessary I will record that also. I ask this because the main reason for me trying this is to reduce detonation to allow more boost. A lot more boost. That being said, I would expect my mph to remain the same or possibly lower if the boost was set the same. (Sorry John, you posted while i was typing ) Joe

Are you sure the plugs are firing at the top of the compression stroke and not at the top of the exhaust stroke? Joe

I'm game but you have to ask her!

I haven't been there since number 2 when they still had it in the parking lot and street out front many years ago. Man I wish I could get out there again! Joe

Actually, according to Singh's web site, .0788" is optimal head to piston clearance for the grooves to work which is pretty large.

Yeah but nothing like a L28's dish. I have another set of clean LS1 heads if you want to give it a shot Joe

Jon, Why not just install a head with grooves and test it for yourself? It's not expensive and you, like me, will take other people's results with a grain of salt. Joe

Sounds like it coild be a clog in the fuel rail on the one bank. I'd try blowing out the fuel rail and have the injectors sent to Witch Hunter to have them cleaned. One thing to remember when having injectors sent out to be cleaned is to install and run them within 30 days. If you don't, you run the risk of having them stick from the cleaning solution used. I waited about a year and 4 out of 6 were stuck. The 30 day recommendation is right on the reciept. Joe

Deez, Sorry to hijack but, any pictures of your exhaust with the cutouts? Joe

A 6 cylinder TEC II sold on here last week for $300 or $350. Search the for sale section.

I searched the web and never found an answer. Does it have to do with the reduced area of the combustion chamber when the charge is ignited or because of the increased movement of the charge into the area of ignition?

That's why my signature says "wanna be tuner". I have no idea what I'm doing so I'm looking for a shortcut!

Yeah the chamber shape is similar but the ports are extremely different which I think will have a huge effect on swirl. I'm not positive because I don't have any documentation to back it up but I would think GM took the port design as well as intake manifold design into account when trying to achieve complete combustion. Do you agree?

Which should help a turbo motor with an 8.5-1 ratio.

What is the pressure reading after it develops the problem and won't start? If you have pressure and can hear the injectors firing while trying to start it, do the plugs get wet? If they do check for spark. If they don't you are back to fuel. All this is dependent on having good fuel pressure.

Are you sure it runs for that long? Are the injectors firing? Have you done the screwdriver to the ear test to check for injector coil firing? Where did you check for fuel pressure and does the FP drop when you open the throttle or does the engine stall if the throttle is cracked? We need more info.

Exactly my thoughts. I wouldn't be doing this to my LS1 motor but a 30 year old head design on top of a short block with less than optimal configuration tells me I have nothing to lose!

I also thought about groove shape. So much so that I started to question why I was doing this. I hesitated on posting I was going to give it a shot as I just didn't feel like hearing how it couldn't work from members more vocal than I. In any event, after looking at a lot of pictures there doesn't seems to be any "correct" way to set up the grooves so I'm just gonna wing it and see what happens. What's the worst that can happen? No additional power and a trashed P90? Joe

I am also intrigued by this. So, having another p90 just lying here doing nothing, I figured I would give it a shot. What I am attempting is to see if I can increase boost by adding the Singh grooves. My bottom end is a 3 liter stroker that uses a diesel crank and custom pistons. The pistons used were designed so that they could be used in many different engine configurations thus they are not specifically for a turbo application. The main drawback to their design is they are flat tops that sit 1mm down in the bore. If you look at the Singh site you will see he says for the grooves to work optimally, there should be 2mm piston to quench pad clearance which is what I have with a 1mm HG. What I should have done was to groove my existing head and test, unfortunately I grooved the new head and also had it cleaned up to match the existing head. When I install the new head, should I see any improvement, I will groove the old head to make sure I see the same type of results. I will report my findings, whether good or bad, on this site. Joe

It's the vacuum reservoir and switches for the HVAC controls. Joe

So is an S30 and an S130 rack the same length? If so, I think my idea of using a RHD rack upsidedown in a LHD car will solve all of these problems. Anyone else agree/disagree? Joe

Dave, FWIW, my Gleason makes the same noise and has the same play. I find it very annoying. Man I must be getting old Joe

Gary, I could be wrong, but I believe the post that the pivot sits on was changed to the shorter post and therefore the different pivot, after 72. Joe

Joey, How about slotting the holes on the mount that bolt to the trans, not the hole in the crossmember? Joe