06-27-2022, 05:24 PM | #1 |
Drives: Chevy Camaro SS Join Date: Nov 2019
Location: Indiana
Posts: 225
|
CID heads, chambers hit pistons
Ok, so as many on here know I had a set of CID heads that had Greg Goods Small chamber program on them. Well once I got the car fired up and went to back out of my garage I heard a weird “knocking” sound. Immediately thought great, bottom end is toast. Pull it back into the garage and get out to listen to where it’s coming from and notice that it’s coming from the top end. So I shut the car off, pull the valve covers and everything checked out there. So I figured I’m already here, might as well just pull the plugs and put a camera in there and saw that the dome on the piston looked odd in one spot. So I pull the heads and to my surprise the pistons were hitting the chambers. It wasn’t much, but it was enough to hear. I ended up sending them out to my good buddy at CTporting since he offered to fix them for me. At that time he had his own port program for CID heads, so I decided to sell the ones I had once he fixed them after seeing the work and flow numbers with a smaller port. Also wanted to spend money with a friends business. Received the heads and just waiting on my exhaust valves from him(we ended up doing a 55* seat on the exhaust side)they were in a separate box and forgot to send them. But he did his SBE program on them and made sure to clearance the chambers enough for me to be able to run the .028 gasket. So if anybody is doing a big N/A build and milling quite a bit and running a .028 or .040 headgasket, double check the clearance even if you check the first time. But needless to say I’m pretty happy with how they turned out and ready to get them bolted on and run/drive the car.
__________________
2017 1SS:Hi-Ram, FBO, OTR ram air, Circle D converter. Previous PB: 11.07 @124 1/4 7.1 @100 1/8 1.6 60’ w/2” longtubes, 95mm hi-ram, OTR ramair, flex fuel |
06-27-2022, 06:23 PM | #2 |
Drives: like an old lady Join Date: Jun 2012
Location: indiana
Posts: 2,395
|
referring to "old" heads
quench was a little tight, eh. was that the cid small chamber option i read about on their website? how much did you mill the cyl heads?
__________________
2016+ camaro: everyone’s first car
|
06-27-2022, 06:52 PM | #3 |
Drives: 6th gen Join Date: Aug 2013
Location: US
Posts: 3,675
|
I think pray did a psa on this last week
__________________
‘22 2SS 1LE M6 Summit White - RF, Flexfuel, LT2 intake, 95mm tb, ATI udp, VT ramair, full 28” dragpack - 11.68@122
‘16 1SS M6 LT2 intake + boltons on DR 11.0@126+ (Sold) |
06-27-2022, 08:14 PM | #4 |
Drives: Chevy Camaro SS Join Date: Nov 2019
Location: Indiana
Posts: 225
|
When we checked before dropping it down in he car all looked to be fine as far as quench goes with the old heads. But yes it was the Greg Good Small Chamber program and they were only milled.030 at the time. The new ones are milled .060.
__________________
2017 1SS:Hi-Ram, FBO, OTR ram air, Circle D converter. Previous PB: 11.07 @124 1/4 7.1 @100 1/8 1.6 60’ w/2” longtubes, 95mm hi-ram, OTR ramair, flex fuel |
06-27-2022, 08:15 PM | #5 |
Drives: Chevy Camaro SS Join Date: Nov 2019
Location: Indiana
Posts: 225
|
Yea, I actually talked with him about mine. I figured I would make a post here for the ones who don’t do Facebook as well
__________________
2017 1SS:Hi-Ram, FBO, OTR ram air, Circle D converter. Previous PB: 11.07 @124 1/4 7.1 @100 1/8 1.6 60’ w/2” longtubes, 95mm hi-ram, OTR ramair, flex fuel |
06-28-2022, 05:10 AM | #6 | |
Drives: 6th gen Join Date: Aug 2013
Location: US
Posts: 3,675
|
Quote:
Facebook sucks
__________________
‘22 2SS 1LE M6 Summit White - RF, Flexfuel, LT2 intake, 95mm tb, ATI udp, VT ramair, full 28” dragpack - 11.68@122
‘16 1SS M6 LT2 intake + boltons on DR 11.0@126+ (Sold) |
|
06-28-2022, 12:52 PM | #7 |
Drives: 14 Camaro SS 1LE Join Date: Feb 2019
Location: Clinton Twp, MI
Posts: 483
|
Even with undecked GM heads, you are likely to hit the head with a .028 head gasket. I would advise running a minimum of .040 quench or else you will run into the same issues.
|
06-28-2022, 03:12 PM | #8 |
Drives: 2018 Camaro SS 1LE Join Date: Jul 2018
Location: Stuttgart, Germany
Posts: 807
|
A .028 inch gasket will still have contact on undecked GM heads? Hmmm...guess I need to order the .040's...thanks, Katech!
__________________
|
06-29-2022, 03:15 PM | #9 | |
Drives: Chevy Camaro SS Join Date: Nov 2019
Location: Indiana
Posts: 225
|
Quote:
I’ve seen CID heads hit just like mine with a .040 gasket as well. I’ve got mine bolted down with a .028 gasket since the post was made. I honestly don’t see it being an issue anymore. Plenty of guys out there running the .028 gasket like myself after having the chambers worked on and having no issues, Brandon Hill being one of them.
__________________
2017 1SS:Hi-Ram, FBO, OTR ram air, Circle D converter. Previous PB: 11.07 @124 1/4 7.1 @100 1/8 1.6 60’ w/2” longtubes, 95mm hi-ram, OTR ramair, flex fuel Last edited by 17camaroSS; 06-29-2022 at 04:56 PM. |
|
07-14-2022, 08:59 PM | #10 |
Drives: 2020 2SS 1LE Join Date: Jun 2011
Location: McKinney, TX
Posts: 108
|
Quench is as outdated as a 23 degree small block Chevy.
|
07-15-2022, 08:29 AM | #11 |
Drives: 6th gen Join Date: Aug 2013
Location: US
Posts: 3,675
|
__________________
‘22 2SS 1LE M6 Summit White - RF, Flexfuel, LT2 intake, 95mm tb, ATI udp, VT ramair, full 28” dragpack - 11.68@122
‘16 1SS M6 LT2 intake + boltons on DR 11.0@126+ (Sold) |
07-16-2022, 09:08 PM | #12 |
Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016
Location: US
Posts: 1,201
|
It looks like I had 0.079-0.065 in in that area on mine, I think the spark plug quench/squish pad thing comes into contact there looking at the impression in the clay, I just can't remember which side its on on the GEN V combustion chambers?:
I have stock heads with a supposedly 0.015 in mill and I am running 0.028 Cometic head gaskets with a 226/238 .635/.630 114 Cam Motion cam. What do you think your compression is at now? I calculate mine at about 12.95:1, I wish I was at 14 or 15:1, I run E85 100% of the time. I really haven't even tried to run 93 and see if it runs without knock. Looks like I measured the quench at about 0.010 using the clay, which is a little difficult but should be accurate just by resting the caliper/depth gauge on the top of the clay and then smashing it into the clay until it hits metal. I really want to cut reliefs in my piston and go with a bigger cam and maybe sacrifice some low end with a wider LSA to help balance out the idle and get a higher stall. Looks like I had about between 0.072 and 0.062 in for PTV for the exhaust valve. I assume the discrepancy in quench between the top and bottom of the piston (0.010 and 0.022) is mostly due to the piston rocking in the bore, although that would be a pretty big rock? |
07-23-2022, 09:33 PM | #13 |
Drives: 2020 2SS 1LE Join Date: Jun 2011
Location: McKinney, TX
Posts: 108
|
Running super tight quench on most of the modern engine is not only pointless it can also lead to some serious failures. 30-40 years ago when dealing with SBC’s and especially BBC’s you had to deal with it and manage it to make compression because typically a 11.5:1 or 12:1 setup would require a massive dome on the piston so to try and cut back on some of that you ran it tight just to make compression. The bigger the dome the harder it was to get the flame front around the piston and clean burn. Modern engines with way smaller chambers don’t require such a thing and you can run a more normal head gasket, smaller valve reliefs in the piston and less of a risk of damage from either the head and piston hitting or bending a rod from hydro locking on high volume fuels (E85 or meth injected setups).
So unless it just has to be done, running a super thin gasket for “quench” is pointless. |
07-24-2022, 06:52 PM | #14 | |
Drives: Chevy Camaro SS Join Date: Nov 2019
Location: Indiana
Posts: 225
|
Quote:
__________________
2017 1SS:Hi-Ram, FBO, OTR ram air, Circle D converter. Previous PB: 11.07 @124 1/4 7.1 @100 1/8 1.6 60’ w/2” longtubes, 95mm hi-ram, OTR ramair, flex fuel |
|
|
|
Post Reply
|
|
|