Help! doing the 4.0 head swap on a 258!
08-11-2004, 09:20 AM
#11
Guest
Posts: n/a
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
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
08-11-2004, 09:20 AM
#12
Guest
Posts: n/a
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
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
08-11-2004, 09:20 AM
#13
Guest
Posts: n/a
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
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
08-11-2004, 09:23 AM
#14
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
No.
You have 2 TDC's. One has the valves closed, one has them both open.
Check the distributor's position.
Mike
Harris Family wrote:
>
> 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
> > >
> > >
> >
> >
You have 2 TDC's. One has the valves closed, one has them both open.
Check the distributor's position.
Mike
Harris Family wrote:
>
> 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
> > >
> > >
> >
> >
08-11-2004, 09:23 AM
#15
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
No.
You have 2 TDC's. One has the valves closed, one has them both open.
Check the distributor's position.
Mike
Harris Family wrote:
>
> 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
> > >
> > >
> >
> >
You have 2 TDC's. One has the valves closed, one has them both open.
Check the distributor's position.
Mike
Harris Family wrote:
>
> 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
> > >
> > >
> >
> >
08-11-2004, 09:23 AM
#16
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
No.
You have 2 TDC's. One has the valves closed, one has them both open.
Check the distributor's position.
Mike
Harris Family wrote:
>
> 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
> > >
> > >
> >
> >
You have 2 TDC's. One has the valves closed, one has them both open.
Check the distributor's position.
Mike
Harris Family wrote:
>
> 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
> > >
> > >
> >
> >
08-11-2004, 09:23 AM
#17
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
No.
You have 2 TDC's. One has the valves closed, one has them both open.
Check the distributor's position.
Mike
Harris Family wrote:
>
> 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
> > >
> > >
> >
> >
You have 2 TDC's. One has the valves closed, one has them both open.
Check the distributor's position.
Mike
Harris Family wrote:
>
> 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
> > >
> > >
> >
> >
08-11-2004, 02:18 PM
#18
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
Have you made sure the timing chain is on right? If the chain is not
installed correectly, there is no telling where the cam is going to be. the
chain must be installed with the crank in the right spot. Actually, the
crank and cam are keyed, you can be off by half because the crank goes
around twice for each rotation of the cam. It sounds like #1 isn't in the
front anymore.
And, I think you probably should be using the 4.0 rockers, etc. I am not
sure on that though.
"Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
news:gJeSc.3870$Qa4.538@twister.socal.rr.com...
> Folks, I'm in a pickle!
> Hope you can help me. I'm in the process of doing the head swap on my '86
> CJ7. Got the head installed no problem. Here's my catch, when I went to
put
> the 258 stock rockers and pushrods back in, my valves were opened on #1
cyl
> when its at TDC. AS we all know this is not good for compression.
Apparently
> either my pushrods are too long or something in the rockers is amiss. Got
> any ideas? Should I be using 4.0l rockers, pivot assemblies, and pushrods
> instead of the old 258 engine parts?
> Thanks for your help.
> Rich Harris
>
>
installed correectly, there is no telling where the cam is going to be. the
chain must be installed with the crank in the right spot. Actually, the
crank and cam are keyed, you can be off by half because the crank goes
around twice for each rotation of the cam. It sounds like #1 isn't in the
front anymore.
And, I think you probably should be using the 4.0 rockers, etc. I am not
sure on that though.
"Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
news:gJeSc.3870$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
>
>
08-11-2004, 02:18 PM
#19
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
Have you made sure the timing chain is on right? If the chain is not
installed correectly, there is no telling where the cam is going to be. the
chain must be installed with the crank in the right spot. Actually, the
crank and cam are keyed, you can be off by half because the crank goes
around twice for each rotation of the cam. It sounds like #1 isn't in the
front anymore.
And, I think you probably should be using the 4.0 rockers, etc. I am not
sure on that though.
"Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
news:gJeSc.3870$Qa4.538@twister.socal.rr.com...
> Folks, I'm in a pickle!
> Hope you can help me. I'm in the process of doing the head swap on my '86
> CJ7. Got the head installed no problem. Here's my catch, when I went to
put
> the 258 stock rockers and pushrods back in, my valves were opened on #1
cyl
> when its at TDC. AS we all know this is not good for compression.
Apparently
> either my pushrods are too long or something in the rockers is amiss. Got
> any ideas? Should I be using 4.0l rockers, pivot assemblies, and pushrods
> instead of the old 258 engine parts?
> Thanks for your help.
> Rich Harris
>
>
installed correectly, there is no telling where the cam is going to be. the
chain must be installed with the crank in the right spot. Actually, the
crank and cam are keyed, you can be off by half because the crank goes
around twice for each rotation of the cam. It sounds like #1 isn't in the
front anymore.
And, I think you probably should be using the 4.0 rockers, etc. I am not
sure on that though.
"Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
news:gJeSc.3870$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
>
>
08-11-2004, 02:18 PM
#20
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
Have you made sure the timing chain is on right? If the chain is not
installed correectly, there is no telling where the cam is going to be. the
chain must be installed with the crank in the right spot. Actually, the
crank and cam are keyed, you can be off by half because the crank goes
around twice for each rotation of the cam. It sounds like #1 isn't in the
front anymore.
And, I think you probably should be using the 4.0 rockers, etc. I am not
sure on that though.
"Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
news:gJeSc.3870$Qa4.538@twister.socal.rr.com...
> Folks, I'm in a pickle!
> Hope you can help me. I'm in the process of doing the head swap on my '86
> CJ7. Got the head installed no problem. Here's my catch, when I went to
put
> the 258 stock rockers and pushrods back in, my valves were opened on #1
cyl
> when its at TDC. AS we all know this is not good for compression.
Apparently
> either my pushrods are too long or something in the rockers is amiss. Got
> any ideas? Should I be using 4.0l rockers, pivot assemblies, and pushrods
> instead of the old 258 engine parts?
> Thanks for your help.
> Rich Harris
>
>
installed correectly, there is no telling where the cam is going to be. the
chain must be installed with the crank in the right spot. Actually, the
crank and cam are keyed, you can be off by half because the crank goes
around twice for each rotation of the cam. It sounds like #1 isn't in the
front anymore.
And, I think you probably should be using the 4.0 rockers, etc. I am not
sure on that though.
"Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
news:gJeSc.3870$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
>
>