Jump to content

Milled VS coolhead


Recommended Posts

Here is the tester I use. I got it off ebay about a year ago. Can't remember what I paid for it.

 

DSCN0366.jpg

 

 

 

Now take a pic of the end of the test end that installs in your head. My guess is it does NOT have a valve in the tip. This is a CRITICAL difference. Usually all those little adapters are a sure sign that you need a different gauge.

Link to comment
Share on other sites

yeah 100 psi is pretty low i have a 95 shee and it read 120 psi in each cylinder after 14 years on the stock pistons before i rebuilt it, im at the same elevation as you to, a cool head is definately the way to go, i love my noss head.

 

A cool head is def not the only way to go, a stock cut head will work just as good as a cool head if your on a budget, if ya got extra cash then the cool heads do look nice, and the removable domes is not nice. If you know what kinda fuel you wanna run and dont care about the bling, or building a sleeper motor than a stock head will do just fine, and if mull engineering ever gets the time lol, there head exchange is hard to beat!

Link to comment
Share on other sites

The problem with your gauge is the adapterthat goes between the gauge and cylinder. Unless it has a check valve in the other adapter it is not getting an accurate reading on the engine. Also, when you check the compression, the engine should be warm, the throttle should be wide open, and you should kick it over until the needle quits climbing. 100 psi seems a little low even for 800 feet, if it was 1800 ft, it would be fine.

Link to comment
Share on other sites

The problem with your gauge is the adapterthat goes between the gauge and cylinder. Unless it has a check valve in the other adapter it is not getting an accurate reading on the engine. Also, when you check the compression, the engine should be warm, the throttle should be wide open, and you should kick it over until the needle quits climbing. 100 psi seems a little low even for 800 feet, if it was 1800 ft, it would be fine.

I run a cut and chambered head that gets me 185 at sea level when fresh, and is at 175 after 7 years on the top end.I have no problems with it.

Link to comment
Share on other sites

This topic is a never ending topic. I have a very aggressive port on my cylinders (real close to a drag port) and I freaked out when I had 135lbs of compression after a fresh top end and a milled head. The reasoning for this is because my exhaust ports have been raised therefore lowering compression. Whether this is true or not im totally positive, but ive spoke to several known guys in the industry and they all said the same thing. I do not have specs on my porting, but JSR performance is the one who ported my cylinders. I also got the milled head from them as well. Im not sure of my elevation, but im in wichita ks. I got soo damn wrapped up in worrying about compression all the time and tearing it back down to bump the compression to 150 lbs that I finally said F it and just ride the damn thing. Mine runs real strong and will beat 450's and raptor 700's all day long with my 135 psi compression. I have a coolhead, but have not installed it yet and wont until after snakehunt. Its dialed in just fine right now and dont feel like f'n with it while im down at snakehunt. I plan on replacing the head when I get back with 20 or 21 cc domes just so I can run 91 octane or a blended fuel.

Link to comment
Share on other sites

  • 2 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...