Mechanical timing with comp cam... weird compression numbers - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > YJ Wrangler Technical Forum > Mechanical timing with comp cam... weird compression numbers

Baseline 4x4 Lifetime Warranty 4340 Chromoly Axle Shaft KiClayton Off Road WJ Long Arm Kits!Clayton Off Road - JK Prototype Gas Tank Skid

Reply
Unread 04-09-2013, 07:52 PM   #1
95yj0645
Registered User
1995 YJ Wrangler 
 
Join Date: May 2010
Location: indiana
Posts: 363
Mechanical timing with comp cam... weird compression numbers

I am trying to start my new 4.6L I built for the yj and it is way out of time. tried setting up the distributor multiple times with no such luck. I finally ran a compression check and I get 50psi on cyl 1 and cyl 6. 2,3,4,5 all have 150 psi. pulled the timing cover and it appeared my chain had moved half a tooth (A to Z brand chain) went and bought a cloyes tonight ( the one I wanted to begin with `). set it up and decided that before I put the cover on I should crank it over and check the compression on those cylinders and they are the exact same, still 50psi. I am running a comp 68-235-4 extreme 4x4 cam. should I try advancing the cam gear ? I am getting frustrated. It has a .030 bore with new pistons and all of my rings were set up and measured exactly the same way. HELP ! this is my only vehicle.

95yj0645 is offline   Reply With Quote
Unread 04-09-2013, 09:09 PM   #2
95yj0645
Registered User
1995 YJ Wrangler 
 
Join Date: May 2010
Location: indiana
Posts: 363
AHHHH! after doing a little more searching on the forum it looks like I timed it on TDC exhaust and not TDC compression now im not sure of my cam position. I guess im going to have to start from scratch tomorrow and pull the valve cover and rotate my cam until both valves are closed on number 1 and then set up my crank. Thank God these are non interference engines..
95yj0645 is offline   Reply With Quote
Unread 04-10-2013, 10:00 AM   #3
95yj0645
Registered User
1995 YJ Wrangler 
 
Join Date: May 2010
Location: indiana
Posts: 363
Bump
__________________
'95 YJ, 4.6L stroker, Ford 8.8, AX15, SYE, SOA, Cage kit, full armor, 35" MT/R Kevlar's
95yj0645 is offline   Reply With Quote
Unread 04-10-2013, 01:00 PM   #4
youngjeepr
Web Wheeler
 
youngjeepr's Avatar
1988 YJ Wrangler 
 
Join Date: Aug 2009
Location: layton UT
Posts: 2,196
What size cam did you get? What is your ENGINE timing set at?
__________________
88 YJ- 4.7l stroker, AW4, SOA, 8.8, hp D30 powertrax no slip,3" front stretch with waggy springs, stock replacement springs in the rear, 35/12.5 r15 goodyear kevlars

Utah Jeep Crew



Build Thread
youngjeepr is offline   Reply With Quote
Unread 04-12-2013, 05:07 AM   #5
95yj0645
Registered User
1995 YJ Wrangler 
 
Join Date: May 2010
Location: indiana
Posts: 363
Engine timing is stock .. Ended up taking timing chain off and rocker arms off and running a compression test getting terrible results. 1-25psi,2-40psi,3-75psi, 4-150,5-140,6-25psi. I pulled the head and 8 out of 12 valves were leaking after my supposed valve job I paid for! Here are some pics after I filled the head with water and set it on it's side.

image-3897088547.jpg



image-3554681932.jpg



image-3613683404.jpg



image-2641039742.jpg
__________________
'95 YJ, 4.6L stroker, Ford 8.8, AX15, SYE, SOA, Cage kit, full armor, 35" MT/R Kevlar's
95yj0645 is offline   Reply With Quote
Unread 04-12-2013, 08:27 AM   #6
Siva283
Registered User
1995 YJ Wrangler 
 
Join Date: May 2011
Location: Falling Waters, WV
Posts: 3,699
I would have used oil not water. You can already see the rust forming. Load that pupy up with some kind of oil to get the moisture out. I would also take it back and have the valve job redone on thier dime since they half asses it.
__________________
1995 YJ. 2 inch BDS Spring lift. 1 inch shackle lift. 1.25 inch JKS Body Lift 33x12.5x15's. Engo 10,000 pound winch.

[QUOTE=Magnum;14117863] I gave the Jeep the required offering of $$, sweat, and blood, and everything works fine now. -- Jim[/QUOTE]

[QUOTE=ldso;16498409]. It started with a $200 axle, and a few thousand dollars later I was done :)[/QUOTE]

[QUOTE=Luuca;16122017]diagnose the real issue before you start going all Obama on it - spending mad cash you'll need for other important things.

Ask me how I know...[/QUOTE]

[QUOTE=Overhead;17658665]this is also my second set of RC springs this year. I'd rather spend the money again and get something that will last.[/QUOTE]
Siva283 is offline   Reply With Quote
Unread 04-12-2013, 08:46 AM   #7
youngjeepr
Web Wheeler
 
youngjeepr's Avatar
1988 YJ Wrangler 
 
Join Date: Aug 2009
Location: layton UT
Posts: 2,196
Wouldn't oil be to thick? I've always used water or coolant
__________________
88 YJ- 4.7l stroker, AW4, SOA, 8.8, hp D30 powertrax no slip,3" front stretch with waggy springs, stock replacement springs in the rear, 35/12.5 r15 goodyear kevlars

Utah Jeep Crew



Build Thread
youngjeepr is offline   Reply With Quote
Unread 04-12-2013, 09:15 AM   #8
Jeepsr4me
Registered User
 
Join Date: Dec 2004
Posts: 4,547
No u use ALCOHOL ..... Not water... or oil.. Oil to thick.
I have verified 100s of valves and alcohol will not pass by a good seal.
Jeepsr4me is offline   Reply With Quote
Unread 04-13-2013, 04:47 AM   #9
95yj0645
Registered User
1995 YJ Wrangler 
 
Join Date: May 2010
Location: indiana
Posts: 363
Who wants to waste alcohol .. Nonetheless I took the head back and they went through it again and it's ready to be picked up (they cleaned the rust ). They did however try telling me a slight amount of seepage is normal until the valves wear in (after the engine runs for awhile). However, I feel like that was a bit excessive , considering it only took about 5 min for cyl 1 and cyl 6 to start leaking that bad.
__________________
'95 YJ, 4.6L stroker, Ford 8.8, AX15, SYE, SOA, Cage kit, full armor, 35" MT/R Kevlar's
95yj0645 is offline   Reply With Quote
Unread 04-13-2013, 05:15 AM   #10
Jeepsr4me
Registered User
 
Join Date: Dec 2004
Posts: 4,547
You may need to find another machinist. Once you lap those valves in, they seal pretty good.
Rubbing alcohol is what I use... You no drink that..
Jeepsr4me is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.