questions about timing chain. - 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 > General Technical Discussions > Engines & Drivetrain > questions about timing chain.

JK specific skid plates from Clayton Off Road Mfg.RCV Heavy Duty Axle Shafts Now Shipping at Baseline4x4.comStainless Steel Door Hinge Pins

Reply
Unread 09-13-2013, 08:46 PM   #1
mustanggarage
Registered User
1990 YJ Wrangler 
 
Join Date: Nov 2011
Location: atlantic, iowa
Posts: 181
questions about timing chain.

Hello. I am posting this thread here and in the YJ section because I really need some help as soon as possible.

I am in the process of doing a head swap 4.0 onto a 4.2 and doing the MPFI conversion at the same time.

I set the engine at TDC and took the distributor cap off confirming that the rotor was pointed at number 1.

so I pulled the head. then I checked the timing chain and found it had a bit too much slack so I pulled the harmonic balancer and the timing cover.

when I pulled the timing cover I found the crank sprocket positioned with the dot toward the cam sprocket. the cam sprocket dot however was 180 out. I rotated it around so the two dots are aligned. here is the pic.



however the rotor looks like this.



now keep in mind this engine was running just fine when I took it apart. but this as far as I know looks like the distributor is in 180 out of time. I called Hesco and asked them about it and they said to just re install everything like I took it out.

so I swapped the timing chain. it looks like this now.


the distributor looks like this.



before reinstalling the head I rotated the engine so the cam sprocket was at 1:00 and the crank sprocket was at 3:00 and counted pins. 15 count just like it should be. reinstalled the head, torqued it properly.

now I need to pull the distributor. the new distributor has a pin in it to keep it from rotating. My concern is that this looks like it is 180 out to me. should I reinstall it like it was? I know it is not that big of a deal to pull the distributor and swap it 180 but I wanted to get some more opinions before I pulled the distributor.

so anyone out there have any opinions?

__________________
My yj: http://www.jeepforum.com/forum/f22/joopacabra-1563169/
mustanggarage is offline   Reply With Quote
Unread 09-17-2013, 01:49 PM   #2
jokerchief462
Wild Wheeler
 
jokerchief462's Avatar
1989 YJ Wrangler 
 
Join Date: Nov 2010
Location: Sin City, Nevada
Posts: 2,828
4 stroke engine. every 180 degrees it comes to that position so i would imagine one or the other is off. Check again to make sure keep things marked or take pictures.
__________________
89YJ 2.5L TBI, AX-5, NP231 SYE, Ford 8.8, Yukon Grizzly, Tom Woods Shaft, 33" BFG T/As, 4" lift, Warn VR10000s.

AF Jeep Club Tail #184
jokerchief462 is offline   Reply With Quote
Unread 09-17-2013, 03:58 PM   #3
mustanggarage
Registered User
1990 YJ Wrangler 
 
Join Date: Nov 2011
Location: atlantic, iowa
Posts: 181
actually I have been working on this for a while since I posted this question. this is the one reply I got that actually seemed to fit my problem. it was from Leee from hesco.

"The timing dots when aligned has the engine at TDC firing #6, also at this time the #1 valves should be a "SPLIT OVERLAP" (that means the exhaust is almost closed and the intake is starting to open). Most engine builders use this to rough degree a cam in."

prior to receiving that answer I had confirmed by placing my finger over the spark plug hole that I am indeed on the compression stroke of number one cylinder.

apparently for some unknown reason that is the way it is supposed to be.

anyway I think I have it figured out now.

thanks.
__________________
My yj: http://www.jeepforum.com/forum/f22/joopacabra-1563169/
mustanggarage 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.