Help! doing the 4.0 head swap on a 258!
#91
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
Mike,
Not trying to be an ***. Just a bit frustrated by my situation. Sorry to
take it out on you guys. I did check the rotor position and its where it
should be. I've been over it a dozn times and the only explanation I can com
up with is that I decked the block .010 last year during a rebuild, and the
head is a reman. It probably has been surfaced as well as new valves and
ground seats. Ground seats would raise the valve stems higher block decking
and head machining would put the rocker bosses anywhere between .020 and god
knows how much closer to the tops of the lifters. Add it all up and
something has to change to compensate. I fugure its got to be the pushrods.
I've read every article and thread I can mine off the internet and all
except one says the rockers are interchangeable. All except another say the
rods are interchangeable. The one exception says his situation was exactly
like mine. As a side note I contacted the guy who had pushrod problems and
he was told by HESCO, who he got his head from, to put washers under the
rocker pivots to compensate for the difference. While it surely would be the
cheapest fix, as he said it is pretty "Mickey Mouse". Not to mention the
stress put on the rocker bosses. I guess I was looking more for someone to
say "yep I had the same problem and this is what I had to do". Not that I
don't appreciate the advice you guys throw out here, because I really do.
You guys are my fifth shop manual, and I really appreciate it.
Rich Harris
1986 (mostly) CJ7. Detroits F/R 4:10s, 33x12.50 BFG MT's, onepiece axles,
revolver shackles, Rubicon Express 2.5" Wrangler lift, Procomp MX6 shocks
(way out perform RS900's BTW), Custom Swingout tirecarrier bumper, and
more...
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:411AC49D.4BB4DD1A@sympatico.ca...
> You didn't seem to want to take our suggestion about opening the
> distributor cap as a second opinion on TDC just to make sure seriously,
> so forgive our double check advice.
>
> It really sounds like you are reading the exhaust/intake stroke instead
> of the compression stroke all across.
>
> Something silly is wrong and putting strange lifters in isn't likely to
> fix it.
>
> Mike
>
> Harris Family wrote:
> >
> > I know how to go to TDC. I just used #1 as an example. Give me an ounce
of
> > credit here guys. All cylinders are wrong. The head must have been
> > resurfaced as well as the block. I went down to Crower this afternoon
and
> > they gave me an adjustable pushrod and a Mechanical lifter. I'm going
that
> > route. Unless you guys can give me a viable alternative.
> > Rich Harris.
> > PS I've rebuilt a bunch of engines but never had to resize pushrods for
a
> > hydraulic cam.....always a first time....I'm going back to GM small
blocks
> > where you can mechanically adjust.
> > "Mike Romain" <romainm@sympatico.ca> wrote in message
> > news:411A67B3.83A0E781@sympatico.ca...
> > > You use the 4.2 ones.
> > >
> > > Mike
> > >
> > > CRWLR wrote:
> > > >
> > > > Spin the crank one full rotation.
> > > >
> > > > the crank goes around twice for every rotation of the cam, so the
crank
> > can
> > > > be at the top on one rotation, and the valves are in transition
between
> > > > exhaust open and intake open. You would have troubles putting the
> > pushrods
> > > > in if this were the case.
> > > >
> > > > Having said that, the rockers and pushrods on the 4.0 could easily
be
> > > > different than on the 4.2.
> > > >
> > > > "Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
> > > > news:xLoSc.1431$aB1.1397@twister.socal.rr.com...
> > > > > The distributor position is irrelevant in this case. The valves
are
> > open
> > > > > because either the pushrods are too long or the rockers are of an
> > > > incorrect
> > > > > design for this head. I never removed the distributor during this
> > whole
> > > > > operation. All I did was pull the old head and bolt on the new.
> > > > > "Jo Bo" <jromas@columbus.rr.com> wrote in message
> > > > > news:08mSc.11877$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
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
Not trying to be an ***. Just a bit frustrated by my situation. Sorry to
take it out on you guys. I did check the rotor position and its where it
should be. I've been over it a dozn times and the only explanation I can com
up with is that I decked the block .010 last year during a rebuild, and the
head is a reman. It probably has been surfaced as well as new valves and
ground seats. Ground seats would raise the valve stems higher block decking
and head machining would put the rocker bosses anywhere between .020 and god
knows how much closer to the tops of the lifters. Add it all up and
something has to change to compensate. I fugure its got to be the pushrods.
I've read every article and thread I can mine off the internet and all
except one says the rockers are interchangeable. All except another say the
rods are interchangeable. The one exception says his situation was exactly
like mine. As a side note I contacted the guy who had pushrod problems and
he was told by HESCO, who he got his head from, to put washers under the
rocker pivots to compensate for the difference. While it surely would be the
cheapest fix, as he said it is pretty "Mickey Mouse". Not to mention the
stress put on the rocker bosses. I guess I was looking more for someone to
say "yep I had the same problem and this is what I had to do". Not that I
don't appreciate the advice you guys throw out here, because I really do.
You guys are my fifth shop manual, and I really appreciate it.
Rich Harris
1986 (mostly) CJ7. Detroits F/R 4:10s, 33x12.50 BFG MT's, onepiece axles,
revolver shackles, Rubicon Express 2.5" Wrangler lift, Procomp MX6 shocks
(way out perform RS900's BTW), Custom Swingout tirecarrier bumper, and
more...
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:411AC49D.4BB4DD1A@sympatico.ca...
> You didn't seem to want to take our suggestion about opening the
> distributor cap as a second opinion on TDC just to make sure seriously,
> so forgive our double check advice.
>
> It really sounds like you are reading the exhaust/intake stroke instead
> of the compression stroke all across.
>
> Something silly is wrong and putting strange lifters in isn't likely to
> fix it.
>
> Mike
>
> Harris Family wrote:
> >
> > I know how to go to TDC. I just used #1 as an example. Give me an ounce
of
> > credit here guys. All cylinders are wrong. The head must have been
> > resurfaced as well as the block. I went down to Crower this afternoon
and
> > they gave me an adjustable pushrod and a Mechanical lifter. I'm going
that
> > route. Unless you guys can give me a viable alternative.
> > Rich Harris.
> > PS I've rebuilt a bunch of engines but never had to resize pushrods for
a
> > hydraulic cam.....always a first time....I'm going back to GM small
blocks
> > where you can mechanically adjust.
> > "Mike Romain" <romainm@sympatico.ca> wrote in message
> > news:411A67B3.83A0E781@sympatico.ca...
> > > You use the 4.2 ones.
> > >
> > > Mike
> > >
> > > CRWLR wrote:
> > > >
> > > > Spin the crank one full rotation.
> > > >
> > > > the crank goes around twice for every rotation of the cam, so the
crank
> > can
> > > > be at the top on one rotation, and the valves are in transition
between
> > > > exhaust open and intake open. You would have troubles putting the
> > pushrods
> > > > in if this were the case.
> > > >
> > > > Having said that, the rockers and pushrods on the 4.0 could easily
be
> > > > different than on the 4.2.
> > > >
> > > > "Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
> > > > news:xLoSc.1431$aB1.1397@twister.socal.rr.com...
> > > > > 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
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
#92
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
Mike,
Not trying to be an ***. Just a bit frustrated by my situation. Sorry to
take it out on you guys. I did check the rotor position and its where it
should be. I've been over it a dozn times and the only explanation I can com
up with is that I decked the block .010 last year during a rebuild, and the
head is a reman. It probably has been surfaced as well as new valves and
ground seats. Ground seats would raise the valve stems higher block decking
and head machining would put the rocker bosses anywhere between .020 and god
knows how much closer to the tops of the lifters. Add it all up and
something has to change to compensate. I fugure its got to be the pushrods.
I've read every article and thread I can mine off the internet and all
except one says the rockers are interchangeable. All except another say the
rods are interchangeable. The one exception says his situation was exactly
like mine. As a side note I contacted the guy who had pushrod problems and
he was told by HESCO, who he got his head from, to put washers under the
rocker pivots to compensate for the difference. While it surely would be the
cheapest fix, as he said it is pretty "Mickey Mouse". Not to mention the
stress put on the rocker bosses. I guess I was looking more for someone to
say "yep I had the same problem and this is what I had to do". Not that I
don't appreciate the advice you guys throw out here, because I really do.
You guys are my fifth shop manual, and I really appreciate it.
Rich Harris
1986 (mostly) CJ7. Detroits F/R 4:10s, 33x12.50 BFG MT's, onepiece axles,
revolver shackles, Rubicon Express 2.5" Wrangler lift, Procomp MX6 shocks
(way out perform RS900's BTW), Custom Swingout tirecarrier bumper, and
more...
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:411AC49D.4BB4DD1A@sympatico.ca...
> You didn't seem to want to take our suggestion about opening the
> distributor cap as a second opinion on TDC just to make sure seriously,
> so forgive our double check advice.
>
> It really sounds like you are reading the exhaust/intake stroke instead
> of the compression stroke all across.
>
> Something silly is wrong and putting strange lifters in isn't likely to
> fix it.
>
> Mike
>
> Harris Family wrote:
> >
> > I know how to go to TDC. I just used #1 as an example. Give me an ounce
of
> > credit here guys. All cylinders are wrong. The head must have been
> > resurfaced as well as the block. I went down to Crower this afternoon
and
> > they gave me an adjustable pushrod and a Mechanical lifter. I'm going
that
> > route. Unless you guys can give me a viable alternative.
> > Rich Harris.
> > PS I've rebuilt a bunch of engines but never had to resize pushrods for
a
> > hydraulic cam.....always a first time....I'm going back to GM small
blocks
> > where you can mechanically adjust.
> > "Mike Romain" <romainm@sympatico.ca> wrote in message
> > news:411A67B3.83A0E781@sympatico.ca...
> > > You use the 4.2 ones.
> > >
> > > Mike
> > >
> > > CRWLR wrote:
> > > >
> > > > Spin the crank one full rotation.
> > > >
> > > > the crank goes around twice for every rotation of the cam, so the
crank
> > can
> > > > be at the top on one rotation, and the valves are in transition
between
> > > > exhaust open and intake open. You would have troubles putting the
> > pushrods
> > > > in if this were the case.
> > > >
> > > > Having said that, the rockers and pushrods on the 4.0 could easily
be
> > > > different than on the 4.2.
> > > >
> > > > "Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
> > > > news:xLoSc.1431$aB1.1397@twister.socal.rr.com...
> > > > > The distributor position is irrelevant in this case. The valves
are
> > open
> > > > > because either the pushrods are too long or the rockers are of an
> > > > incorrect
> > > > > design for this head. I never removed the distributor during this
> > whole
> > > > > operation. All I did was pull the old head and bolt on the new.
> > > > > "Jo Bo" <jromas@columbus.rr.com> wrote in message
> > > > > news:08mSc.11877$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
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
Not trying to be an ***. Just a bit frustrated by my situation. Sorry to
take it out on you guys. I did check the rotor position and its where it
should be. I've been over it a dozn times and the only explanation I can com
up with is that I decked the block .010 last year during a rebuild, and the
head is a reman. It probably has been surfaced as well as new valves and
ground seats. Ground seats would raise the valve stems higher block decking
and head machining would put the rocker bosses anywhere between .020 and god
knows how much closer to the tops of the lifters. Add it all up and
something has to change to compensate. I fugure its got to be the pushrods.
I've read every article and thread I can mine off the internet and all
except one says the rockers are interchangeable. All except another say the
rods are interchangeable. The one exception says his situation was exactly
like mine. As a side note I contacted the guy who had pushrod problems and
he was told by HESCO, who he got his head from, to put washers under the
rocker pivots to compensate for the difference. While it surely would be the
cheapest fix, as he said it is pretty "Mickey Mouse". Not to mention the
stress put on the rocker bosses. I guess I was looking more for someone to
say "yep I had the same problem and this is what I had to do". Not that I
don't appreciate the advice you guys throw out here, because I really do.
You guys are my fifth shop manual, and I really appreciate it.
Rich Harris
1986 (mostly) CJ7. Detroits F/R 4:10s, 33x12.50 BFG MT's, onepiece axles,
revolver shackles, Rubicon Express 2.5" Wrangler lift, Procomp MX6 shocks
(way out perform RS900's BTW), Custom Swingout tirecarrier bumper, and
more...
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:411AC49D.4BB4DD1A@sympatico.ca...
> You didn't seem to want to take our suggestion about opening the
> distributor cap as a second opinion on TDC just to make sure seriously,
> so forgive our double check advice.
>
> It really sounds like you are reading the exhaust/intake stroke instead
> of the compression stroke all across.
>
> Something silly is wrong and putting strange lifters in isn't likely to
> fix it.
>
> Mike
>
> Harris Family wrote:
> >
> > I know how to go to TDC. I just used #1 as an example. Give me an ounce
of
> > credit here guys. All cylinders are wrong. The head must have been
> > resurfaced as well as the block. I went down to Crower this afternoon
and
> > they gave me an adjustable pushrod and a Mechanical lifter. I'm going
that
> > route. Unless you guys can give me a viable alternative.
> > Rich Harris.
> > PS I've rebuilt a bunch of engines but never had to resize pushrods for
a
> > hydraulic cam.....always a first time....I'm going back to GM small
blocks
> > where you can mechanically adjust.
> > "Mike Romain" <romainm@sympatico.ca> wrote in message
> > news:411A67B3.83A0E781@sympatico.ca...
> > > You use the 4.2 ones.
> > >
> > > Mike
> > >
> > > CRWLR wrote:
> > > >
> > > > Spin the crank one full rotation.
> > > >
> > > > the crank goes around twice for every rotation of the cam, so the
crank
> > can
> > > > be at the top on one rotation, and the valves are in transition
between
> > > > exhaust open and intake open. You would have troubles putting the
> > pushrods
> > > > in if this were the case.
> > > >
> > > > Having said that, the rockers and pushrods on the 4.0 could easily
be
> > > > different than on the 4.2.
> > > >
> > > > "Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
> > > > news:xLoSc.1431$aB1.1397@twister.socal.rr.com...
> > > > > 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
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
#93
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
Mike,
Not trying to be an ***. Just a bit frustrated by my situation. Sorry to
take it out on you guys. I did check the rotor position and its where it
should be. I've been over it a dozn times and the only explanation I can com
up with is that I decked the block .010 last year during a rebuild, and the
head is a reman. It probably has been surfaced as well as new valves and
ground seats. Ground seats would raise the valve stems higher block decking
and head machining would put the rocker bosses anywhere between .020 and god
knows how much closer to the tops of the lifters. Add it all up and
something has to change to compensate. I fugure its got to be the pushrods.
I've read every article and thread I can mine off the internet and all
except one says the rockers are interchangeable. All except another say the
rods are interchangeable. The one exception says his situation was exactly
like mine. As a side note I contacted the guy who had pushrod problems and
he was told by HESCO, who he got his head from, to put washers under the
rocker pivots to compensate for the difference. While it surely would be the
cheapest fix, as he said it is pretty "Mickey Mouse". Not to mention the
stress put on the rocker bosses. I guess I was looking more for someone to
say "yep I had the same problem and this is what I had to do". Not that I
don't appreciate the advice you guys throw out here, because I really do.
You guys are my fifth shop manual, and I really appreciate it.
Rich Harris
1986 (mostly) CJ7. Detroits F/R 4:10s, 33x12.50 BFG MT's, onepiece axles,
revolver shackles, Rubicon Express 2.5" Wrangler lift, Procomp MX6 shocks
(way out perform RS900's BTW), Custom Swingout tirecarrier bumper, and
more...
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:411AC49D.4BB4DD1A@sympatico.ca...
> You didn't seem to want to take our suggestion about opening the
> distributor cap as a second opinion on TDC just to make sure seriously,
> so forgive our double check advice.
>
> It really sounds like you are reading the exhaust/intake stroke instead
> of the compression stroke all across.
>
> Something silly is wrong and putting strange lifters in isn't likely to
> fix it.
>
> Mike
>
> Harris Family wrote:
> >
> > I know how to go to TDC. I just used #1 as an example. Give me an ounce
of
> > credit here guys. All cylinders are wrong. The head must have been
> > resurfaced as well as the block. I went down to Crower this afternoon
and
> > they gave me an adjustable pushrod and a Mechanical lifter. I'm going
that
> > route. Unless you guys can give me a viable alternative.
> > Rich Harris.
> > PS I've rebuilt a bunch of engines but never had to resize pushrods for
a
> > hydraulic cam.....always a first time....I'm going back to GM small
blocks
> > where you can mechanically adjust.
> > "Mike Romain" <romainm@sympatico.ca> wrote in message
> > news:411A67B3.83A0E781@sympatico.ca...
> > > You use the 4.2 ones.
> > >
> > > Mike
> > >
> > > CRWLR wrote:
> > > >
> > > > Spin the crank one full rotation.
> > > >
> > > > the crank goes around twice for every rotation of the cam, so the
crank
> > can
> > > > be at the top on one rotation, and the valves are in transition
between
> > > > exhaust open and intake open. You would have troubles putting the
> > pushrods
> > > > in if this were the case.
> > > >
> > > > Having said that, the rockers and pushrods on the 4.0 could easily
be
> > > > different than on the 4.2.
> > > >
> > > > "Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
> > > > news:xLoSc.1431$aB1.1397@twister.socal.rr.com...
> > > > > The distributor position is irrelevant in this case. The valves
are
> > open
> > > > > because either the pushrods are too long or the rockers are of an
> > > > incorrect
> > > > > design for this head. I never removed the distributor during this
> > whole
> > > > > operation. All I did was pull the old head and bolt on the new.
> > > > > "Jo Bo" <jromas@columbus.rr.com> wrote in message
> > > > > news:08mSc.11877$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
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
Not trying to be an ***. Just a bit frustrated by my situation. Sorry to
take it out on you guys. I did check the rotor position and its where it
should be. I've been over it a dozn times and the only explanation I can com
up with is that I decked the block .010 last year during a rebuild, and the
head is a reman. It probably has been surfaced as well as new valves and
ground seats. Ground seats would raise the valve stems higher block decking
and head machining would put the rocker bosses anywhere between .020 and god
knows how much closer to the tops of the lifters. Add it all up and
something has to change to compensate. I fugure its got to be the pushrods.
I've read every article and thread I can mine off the internet and all
except one says the rockers are interchangeable. All except another say the
rods are interchangeable. The one exception says his situation was exactly
like mine. As a side note I contacted the guy who had pushrod problems and
he was told by HESCO, who he got his head from, to put washers under the
rocker pivots to compensate for the difference. While it surely would be the
cheapest fix, as he said it is pretty "Mickey Mouse". Not to mention the
stress put on the rocker bosses. I guess I was looking more for someone to
say "yep I had the same problem and this is what I had to do". Not that I
don't appreciate the advice you guys throw out here, because I really do.
You guys are my fifth shop manual, and I really appreciate it.
Rich Harris
1986 (mostly) CJ7. Detroits F/R 4:10s, 33x12.50 BFG MT's, onepiece axles,
revolver shackles, Rubicon Express 2.5" Wrangler lift, Procomp MX6 shocks
(way out perform RS900's BTW), Custom Swingout tirecarrier bumper, and
more...
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:411AC49D.4BB4DD1A@sympatico.ca...
> You didn't seem to want to take our suggestion about opening the
> distributor cap as a second opinion on TDC just to make sure seriously,
> so forgive our double check advice.
>
> It really sounds like you are reading the exhaust/intake stroke instead
> of the compression stroke all across.
>
> Something silly is wrong and putting strange lifters in isn't likely to
> fix it.
>
> Mike
>
> Harris Family wrote:
> >
> > I know how to go to TDC. I just used #1 as an example. Give me an ounce
of
> > credit here guys. All cylinders are wrong. The head must have been
> > resurfaced as well as the block. I went down to Crower this afternoon
and
> > they gave me an adjustable pushrod and a Mechanical lifter. I'm going
that
> > route. Unless you guys can give me a viable alternative.
> > Rich Harris.
> > PS I've rebuilt a bunch of engines but never had to resize pushrods for
a
> > hydraulic cam.....always a first time....I'm going back to GM small
blocks
> > where you can mechanically adjust.
> > "Mike Romain" <romainm@sympatico.ca> wrote in message
> > news:411A67B3.83A0E781@sympatico.ca...
> > > You use the 4.2 ones.
> > >
> > > Mike
> > >
> > > CRWLR wrote:
> > > >
> > > > Spin the crank one full rotation.
> > > >
> > > > the crank goes around twice for every rotation of the cam, so the
crank
> > can
> > > > be at the top on one rotation, and the valves are in transition
between
> > > > exhaust open and intake open. You would have troubles putting the
> > pushrods
> > > > in if this were the case.
> > > >
> > > > Having said that, the rockers and pushrods on the 4.0 could easily
be
> > > > different than on the 4.2.
> > > >
> > > > "Harris Family" <SHARRIS11nospam@san.rr.com> wrote in message
> > > > news:xLoSc.1431$aB1.1397@twister.socal.rr.com...
> > > > > 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
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
#94
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
Harris Family wrote:
> Quite simply, Pull the spark plug from #1 and feel the air rush out as you
> turn the crank to the 0degree mark. The air rush is the compression stroke
> bringing you to TDC.
>
This only works when the cam timing is correct.....and isnt that what
were trying to find out ????
#95
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
Harris Family wrote:
> Quite simply, Pull the spark plug from #1 and feel the air rush out as you
> turn the crank to the 0degree mark. The air rush is the compression stroke
> bringing you to TDC.
>
This only works when the cam timing is correct.....and isnt that what
were trying to find out ????
#96
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
Harris Family wrote:
> Quite simply, Pull the spark plug from #1 and feel the air rush out as you
> turn the crank to the 0degree mark. The air rush is the compression stroke
> bringing you to TDC.
>
This only works when the cam timing is correct.....and isnt that what
were trying to find out ????
#97
Guest
Posts: n/a
Re: Help! doing the 4.0 head swap on a 258!
Harris Family wrote:
> Quite simply, Pull the spark plug from #1 and feel the air rush out as you
> turn the crank to the 0degree mark. The air rush is the compression stroke
> bringing you to TDC.
>
This only works when the cam timing is correct.....and isnt that what
were trying to find out ????