Help with 360, too much comp?

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RustyRatRod said:
pee wang?
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I consider it pee wang, ...it sucks... We are up , ten to fifteen percent alcohol "blend", depending on the seasons. Who the hell knows, what the blend is, Rob.(any progress, on RobKat,lol?)
 
Abodybomber said:
I consider it pee wang, ...it sucks... We are up , ten to fifteen percent alcohol "blend", depending on the seasons. Who the hell knows, what the blend is, Rob.(any progress, on RobKat,lol?)
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Naw, right now I am doin some work for PanGasket in another truck he got. Since he works all the time I thought I would help him out.
 
Well I have attached a pic just for s&g , I appreciate all the help, I'm still learning a lot and didn't realize how much more detail this really required 😑🔫 but I understand when your trying to reach a specific combo you have to get specific. I know from testing I won't hit the piston but I need to get some clay and measure the quench exactly, and I'll update on here.
 

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I thought I added this but I measured with a straight edge and feeler gauge and the pistons the highest point is .036 out of the hole. I'm picking up a tool from my buddy to measure it exactly and will update tonight.
 
Take the pistons and rods out, and have a shop with a Bridgeport take .031 off them, and run the .039 compressed Felpro gasket. No need to do anything more but deglaze the bores, file a fresh set of rings, and put it back together.
 
1972orangebeast said:
Well I have attached a pic just for s&g , I appreciate all the help, I'm still learning a lot and didn't realize how much more detail this really required 😑🔫 but I understand when your trying to reach a specific combo you have to get specific. I know from testing I won't hit the piston but I need to get some clay and measure the quench exactly, and I'll update on here.
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As I mentioned earlier, here is a thread that can show you how to check the compression of your specific parts combination. No bull... Not numbers from a book... Your true compression....


What size are your combustion chambers? You may be ok with a .040" to .055" head gasket with what you have and run with it...
 
I got my Pistons measured pretty accurately with my dial indicator. Piston deck is below the block deck height .025 and the highest point in the dome is above the block deck .020 .
 
While you're at it, might as well CC the heads (for accuracy) unless you already know and are positive how many CC's they are. Just sayin'!
 
I got some clay and double checked the quench area and looked real good, solid clay all the way through and good thickness, and this was with a used felpro gasket that's .045 thick. I attached a photo
 

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The real answer is to have the pistons milled, re-balance and reassemble. May not be cheap but will fix the issue.
 
My 360, at one time,ran 11.2 with; closed chamber Eddies, zero deck,.020 gasket for .020 Quench, with the 292/509 cam ,on 87E10 Canadian pee wang. ....yes87. No worries. Over 200psi on my gauge.
 
So what was the clay thickness?
 
F*** winter blend fuel! I ran 10.7 static on my old 340 on 91 with no issues @ all & had a 244 247 @ .050 .545 .545 lift comp cam. also had reeeeal loose converter & 4.10's out back. So it never really got a loaded hard below 3500 rpm. no ping ever. Now my high comp 273 on the other hand with tighter converter & 3.23's don't like winter blend s***!
 
I havent measured the clay, waiting for it to harden and they mic it. Also Im running a 6 speed trans and 4:56 out back so really I dont think a big cam would be an issue for me. But itll prob be driven around town a lot too, and with my over drive ill be around 2k at 70 would that be an issue with big cam?
 
It looks like "good thickness" is relative. It doesn;t look "good" to me. Cut it off with a razor blade and stack some feeler gages to see where it is. If it's less than .030 you 're still too tight for my taste.
 
Shouldnt be,& what I ment was when I put the hammer down the convert would flash up to 3500 or so never letting the motor under load go below 3500 rpm cruise was fine no real load on motor. I ran 12 deg base & 34 total all in by 2800.
 
Are you confusing detonation with inadequate piston to head clearance to allow for thermal expansion?
Cruising at too low an rpm for your cam size,does two things.Firstly,if your cruising at an rpm where the engine is still operating under low vacuum due to inefficient cylinder filling (reversion) You will/may be running richer than necessary and mpgs will suffer.And if its really rich, some of that fuel will; a) still be burning in the header, and b) end up in the oil. And the second thing is; its really hard to get enough timing into the fire, to be running efficiently in the first place.
-Having said that, the 284 cam will likely be just fine at 2000. Is that cruise rpm a calculated number or an actual real world " thats where it cruises" number. I mean a 3500 TC could be slipping a bit, right?
 
I have a manual 6 speed in the car with .05 overdrive, 18-2k is estimated woth 4:56 , right now I have 3:91 and isn't enough gear. I calculated tire size, gears and trans gears, and 35,45,60-70 are all going to be around that 2k mark.

And overall I'm worried about piston clearance and detonation. From all my measurements with a .050 head gasket I'll have .030 of quench(hopefully I'm using that correctly). It still prob would hurt to have Pistons grounded down .010 just to make sure I'm fine. Just sucks cause rings , rods and Pistons have all been balanced :/ but some times have to do what works and prevents headaches in a couple months.

I'll have to get some supplies and calculate real cc numbers filling that link that someone posted. That's going to be the best bet and get an exact comp ratio.
 
1972orangebeast said:
I have a manual 6 speed in the car with .05 overdrive, 18-2k is estimated woth 4:56 , right now I have 3:91 and isn't enough gear. I calculated tire size, gears and trans gears, and 35,45,60-70 are all going to be around that 2k mark.

And overall I'm worried about piston clearance and detonation. From all my measurements with a .050 head gasket I'll have .030 of quench(hopefully I'm using that correctly). It still prob would hurt to have Pistons grounded down .010 just to make sure I'm fine. Just sucks cause rings , rods and Pistons have all been balanced :/ but some times have to do what works and prevents headaches in a couple months.

I'll have to get some supplies and calculate real cc numbers filling that link that someone posted. That's going to be the best bet and get an exact comp ratio.
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You should be alright with .030" clearance. I wouldn't rev the thing over 6500 rpm's ! Probably starts loosing steam after 5500 anyway. As far as compression goes, my 416" static compression is 11.864, dynamic comp is 9.618, with Edelbrock heads ootb, 4.86 gear, 833 4 spd. Passon Performance overdrive gear set, and this cam. I run it on 93 octane. I would not cut the pistons unless you cant get enough piston clearance. There is plenty of material you can remove from the heads in the combustion chamber to lower your compression a few cc's. Just don't want to see you have to rebalance if it's not necessary.
 

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Oops. I got mixed up; re trannys
You should be fine with a true .030 quench.
I ran .020 quench, 1or maybe 2 summers, with KB107s , oem rods,Eddies and up to 7200. No contact.
-I was running a zero deck. I swapped that .020 gasket out for a .039.I chickened out. And I went to a smaller cam. I didnt like that 292/509. The power was just too far away for street duty. It was like riding a 2-stroke dirtbike; nothing, nothing,nothing, bang it hits and done. The power didnt hit til 40+mph in 1st with 3.55s. What good is that, said I, on the street?I even tried 4.30s. Still too far away.I wasnt thinking when I bought that cam.I was too focused on Hp.Well it made lots of that, allright.
-I needed torque in 2nd gear and 25 mph. That would be 4.30s and 2600rpm.I went to a 223/230 cam,a DP750, and added a GearVendor O/D. A lot less up top, but a ton more at speeds I normally drive at.That cam was F-u-n. Right up until it dropped 2 lobes into the pan.
Next I went to a 232* cam, a 3.09 low, and back to 3.55s. Thats where Im at today, and staying.Been running .034quench( +.005deck now) for about 80,000(guessing) miles now.
 
Yea I don't plan to run the car much past 5500 anyway, might get a slightly bigger can but I have 1.6 rockers too of forgot to add that will help with the current cam. Only other thing is to check the valves with those Pistons just to make sure they don't touch.

Also anyone have a part number for a head gasket bigger than .050? I'm ok with going thicker.
 
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