Help! doing the 4.0 head swap on a 258!
 

Folks, I'm in a pickle!
Hope you can help me. I'm in the process of doing the head swap on my '86
CJ7. Got the head installed no problem. Here's my catch, when I went to put
the 258 stock rockers and pushrods back in, my valves were opened on #1 cyl
when its at TDC. AS we all know this is not good for compression. Apparently
either my pushrods are too long or something in the rockers is amiss. Got
any ideas? Should I be using 4.0l rockers, pivot assemblies, and pushrods
instead of the old 258 engine parts?
Thanks for your help.
Rich Harris

Re: Help! doing the 4.0 head swap on a 258!
 

Maybe a dumb question but have you checked the position of the distributor
rotor for pointing to #1 cylinder? If not try turning the crank 360 degrees.

JoBo

"Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
news:gJeSc.3870$Qa4.538@twister.socal.rr.com...
> Folks, I'm in a pickle!
> Hope you can help me. I'm in the process of doing the head swap on my '86
> CJ7. Got the head installed no problem. Here's my catch, when I went to put
> the 258 stock rockers and pushrods back in, my valves were opened on #1 cyl
> when its at TDC. AS we all know this is not good for compression. Apparently
> either my pushrods are too long or something in the rockers is amiss. Got
> any ideas? Should I be using 4.0l rockers, pivot assemblies, and pushrods
> instead of the old 258 engine parts?
> Thanks for your help.
> Rich Harris
>
>

Re: Help! doing the 4.0 head swap on a 258!
 

Maybe a dumb question but have you checked the position of the distributor
rotor for pointing to #1 cylinder? If not try turning the crank 360 degrees.

JoBo

"Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
news:gJeSc.3870$Qa4.538@twister.socal.rr.com...
> Folks, I'm in a pickle!
> Hope you can help me. I'm in the process of doing the head swap on my '86
> CJ7. Got the head installed no problem. Here's my catch, when I went to put
> the 258 stock rockers and pushrods back in, my valves were opened on #1 cyl
> when its at TDC. AS we all know this is not good for compression. Apparently
> either my pushrods are too long or something in the rockers is amiss. Got
> any ideas? Should I be using 4.0l rockers, pivot assemblies, and pushrods
> instead of the old 258 engine parts?
> Thanks for your help.
> Rich Harris
>
>

Re: Help! doing the 4.0 head swap on a 258!
 

Maybe a dumb question but have you checked the position of the distributor
rotor for pointing to #1 cylinder? If not try turning the crank 360 degrees.

JoBo

"Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
news:gJeSc.3870$Qa4.538@twister.socal.rr.com...
> Folks, I'm in a pickle!
> Hope you can help me. I'm in the process of doing the head swap on my '86
> CJ7. Got the head installed no problem. Here's my catch, when I went to put
> the 258 stock rockers and pushrods back in, my valves were opened on #1 cyl
> when its at TDC. AS we all know this is not good for compression. Apparently
> either my pushrods are too long or something in the rockers is amiss. Got
> any ideas? Should I be using 4.0l rockers, pivot assemblies, and pushrods
> instead of the old 258 engine parts?
> Thanks for your help.
> Rich Harris
>
>

Re: Help! doing the 4.0 head swap on a 258!
 

Maybe a dumb question but have you checked the position of the distributor
rotor for pointing to #1 cylinder? If not try turning the crank 360 degrees.

JoBo

"Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
news:gJeSc.3870$Qa4.538@twister.socal.rr.com...
> Folks, I'm in a pickle!
> Hope you can help me. I'm in the process of doing the head swap on my '86
> CJ7. Got the head installed no problem. Here's my catch, when I went to put
> the 258 stock rockers and pushrods back in, my valves were opened on #1 cyl
> when its at TDC. AS we all know this is not good for compression. Apparently
> either my pushrods are too long or something in the rockers is amiss. Got
> any ideas? Should I be using 4.0l rockers, pivot assemblies, and pushrods
> instead of the old 258 engine parts?
> Thanks for your help.
> Rich Harris
>
>

Re: Help! doing the 4.0 head swap on a 258!
 

The distributor position is irrelevant in this case. The valves are open
because either the pushrods are too long or the rockers are of an incorrect
design for this head. I never removed the distributor during this whole
operation. All I did was pull the old head and bolt on the new.
"Jo Bo" <jromas@columbus.rr.com> wrote in message
news:08mSc.11877$Nl1.1300@fe1.columbus.rr.com...
> Maybe a dumb question but have you checked the position of the distributor
> rotor for pointing to #1 cylinder? If not try turning the crank 360
degrees.
>
> JoBo
>
> "Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
> news:gJeSc.3870$Qa4.538@twister.socal.rr.com...
> > Folks, I'm in a pickle!
> > Hope you can help me. I'm in the process of doing the head swap on my
'86
> > CJ7. Got the head installed no problem. Here's my catch, when I went to
put
> > the 258 stock rockers and pushrods back in, my valves were opened on #1
cyl
> > when its at TDC. AS we all know this is not good for compression.
Apparently
> > either my pushrods are too long or something in the rockers is amiss.
Got
> > any ideas? Should I be using 4.0l rockers, pivot assemblies, and
pushrods
> > instead of the old 258 engine parts?
> > Thanks for your help.
> > Rich Harris
> >
> >
>
>

Re: Help! doing the 4.0 head swap on a 258!
 

The distributor position is irrelevant in this case. The valves are open
because either the pushrods are too long or the rockers are of an incorrect
design for this head. I never removed the distributor during this whole
operation. All I did was pull the old head and bolt on the new.
"Jo Bo" <jromas@columbus.rr.com> wrote in message
news:08mSc.11877$Nl1.1300@fe1.columbus.rr.com...
> Maybe a dumb question but have you checked the position of the distributor
> rotor for pointing to #1 cylinder? If not try turning the crank 360
degrees.
>
> JoBo
>
> "Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
> news:gJeSc.3870$Qa4.538@twister.socal.rr.com...
> > Folks, I'm in a pickle!
> > Hope you can help me. I'm in the process of doing the head swap on my
'86
> > CJ7. Got the head installed no problem. Here's my catch, when I went to
put
> > the 258 stock rockers and pushrods back in, my valves were opened on #1
cyl
> > when its at TDC. AS we all know this is not good for compression.
Apparently
> > either my pushrods are too long or something in the rockers is amiss.
Got
> > any ideas? Should I be using 4.0l rockers, pivot assemblies, and
pushrods
> > instead of the old 258 engine parts?
> > Thanks for your help.
> > Rich Harris
> >
> >
>
>

Re: Help! doing the 4.0 head swap on a 258!
 

The distributor position is irrelevant in this case. The valves are open
because either the pushrods are too long or the rockers are of an incorrect
design for this head. I never removed the distributor during this whole
operation. All I did was pull the old head and bolt on the new.
"Jo Bo" <jromas@columbus.rr.com> wrote in message
news:08mSc.11877$Nl1.1300@fe1.columbus.rr.com...
> Maybe a dumb question but have you checked the position of the distributor
> rotor for pointing to #1 cylinder? If not try turning the crank 360
degrees.
>
> JoBo
>
> "Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
> news:gJeSc.3870$Qa4.538@twister.socal.rr.com...
> > Folks, I'm in a pickle!
> > Hope you can help me. I'm in the process of doing the head swap on my
'86
> > CJ7. Got the head installed no problem. Here's my catch, when I went to
put
> > the 258 stock rockers and pushrods back in, my valves were opened on #1
cyl
> > when its at TDC. AS we all know this is not good for compression.
Apparently
> > either my pushrods are too long or something in the rockers is amiss.
Got
> > any ideas? Should I be using 4.0l rockers, pivot assemblies, and
pushrods
> > instead of the old 258 engine parts?
> > Thanks for your help.
> > Rich Harris
> >
> >
>
>

Re: Help! doing the 4.0 head swap on a 258!
 

The distributor position is irrelevant in this case. The valves are open
because either the pushrods are too long or the rockers are of an incorrect
design for this head. I never removed the distributor during this whole
operation. All I did was pull the old head and bolt on the new.
"Jo Bo" <jromas@columbus.rr.com> wrote in message
news:08mSc.11877$Nl1.1300@fe1.columbus.rr.com...
> Maybe a dumb question but have you checked the position of the distributor
> rotor for pointing to #1 cylinder? If not try turning the crank 360
degrees.
>
> JoBo
>
> "Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
> news:gJeSc.3870$Qa4.538@twister.socal.rr.com...
> > Folks, I'm in a pickle!
> > Hope you can help me. I'm in the process of doing the head swap on my
'86
> > CJ7. Got the head installed no problem. Here's my catch, when I went to
put
> > the 258 stock rockers and pushrods back in, my valves were opened on #1
cyl
> > when its at TDC. AS we all know this is not good for compression.
Apparently
> > either my pushrods are too long or something in the rockers is amiss.
Got
> > any ideas? Should I be using 4.0l rockers, pivot assemblies, and
pushrods
> > instead of the old 258 engine parts?
> > Thanks for your help.
> > Rich Harris
> >
> >
>
>

Re: Help! doing the 4.0 head swap on a 258!
 

You do have 2 TDC positions for #1. One is the compression stroke and
the other is in between the exhaust and intake so both valves are tight.

Other than that, did the timing chain get moved?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Harris Family wrote:
>
> Folks, I'm in a pickle!
> Hope you can help me. I'm in the process of doing the head swap on my '86
> CJ7. Got the head installed no problem. Here's my catch, when I went to put
> the 258 stock rockers and pushrods back in, my valves were opened on #1 cyl
> when its at TDC. AS we all know this is not good for compression. Apparently
> either my pushrods are too long or something in the rockers is amiss. Got
> any ideas? Should I be using 4.0l rockers, pivot assemblies, and pushrods
> instead of the old 258 engine parts?
> Thanks for your help.
> Rich Harris