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Topic: New engine combo and pushrods dont fit. (Read 1659 times) previous topic - next topic

New engine combo and pushrods dont fit.

comp cams 276hr14
GT40p heads
stock valves
Crane springs..

My pushrods dont fit :mad:

They are not tight when its all bolted down.  It should be just tight enough that I have no slack but I can still turn the pushrod.  Well I can wiggle that thing around like crazy!!  Maybe 1/32 gap between the pushrod and the rocker.  Why?!?  Only thing I can think of is the base circle is smaller on the comp cam than the explorer cam.  If I had stud mount rockers I could take out the slack.  But I don't.  I guess I need new pushrods.  Mustang HO pushrods are the same exact length as the explorer one, as well as the lifters.. no difference.
One 88

New engine combo and pushrods dont fit.

Reply #1
Are the lifters new??? If not sometimes deposits will not allow the plunger to move back toward the upper portion of it's travel... I had just this situation on the '86 Stang I installed the 1.7 Cobras on... For some reason, was all the exhausts... I just spun it over a few times and they snugged up(yeah I know your's is on the stand)...

New engine combo and pushrods dont fit.

Reply #2
No they are not new but they are very clean.  Its all of them, they are an equal amount too short.  And its more minute than my originally stated 1/32, more like 1/64.  Called Nick up and he found a set of pushrods at Jegs that are 6.272 long instead of the stock 6.250.
One 88

New engine combo and pushrods dont fit.

Reply #3
for the difference your talking, .022 is a far cry from a 64th of an inch.

my bet is your gonna be fine with em after the lifters pump up.  New lifters are tricky like that. Yeah they should be touching but they should also have a tiny bit of play as well as rotation.  a 64th qualifies as a tiny bit to me but its your call.  when you put in the new pushrods, you prob wont be able to spin them at all after your lifters pump up. dono if youve considered that and if they might keep the valves from fully closing or not.  i guess you'll find out soon enough on a compression test.

i would think of this as a possible good thing if the stock ones work cause you would possibly reduce valve over lap.

mine are stock but im 7/16'' studed adjustable rockers.

New engine combo and pushrods dont fit.

Reply #4
Hmm mine has GT40P heads, Comp Magnum 266HR cam, Comp springs, 1.6 roller rockers, and the stock size pushrods work fine:dunno:
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.


New engine combo and pushrods dont fit.

Reply #6
I just did mine twice because they did pump up.
Old Grey Cat to this.88 Cat, 5.0 HO, CW mounts, mass air, CI custom cam, afr165's, Tmoss worked cobra intake, BBK shorty's,off road h pipe, magnaflow ex. T-5,spec stage 2 clutch, 8.8 373 TC trac loc, che ajustables with bullits on the rear. 11" brakes up front. +

New engine combo and pushrods dont fit.

Reply #7
Buy an adjustable pushrod and make a solid lifter out of a spare hydraulic roller lifter and measure. There are some good write ups on the whole proceedure on corral.net if you do a search there. Also the TFS website explains how to make a solid checking lifter out of a stock Ford hyd roller.

I'm thinking it's the cam base circle like you mentioned above. Definitely measure though. You can lose alot of performance with the wrong length pushrods.
[SIGPIC][/SIGPIC]
86 5.0 Turbocoupe (Katrina), 87 5.0 Sport (Rita)

New engine combo and pushrods dont fit.

Reply #8
yeah, either that or have the fulcrums shafed to whatever mathmatical amount you think you need cut off.  its not like nobody can find fulcrums you know.
i dont see anything wrong with doing this, its just a matter of matching your valve train to the cam.

this would be the easiest thing to do if the longer rods dont feel right.

New engine combo and pushrods dont fit.

Reply #9
Swapped the stock camshaft back in and everything fits fine.
One 88

New engine combo and pushrods dont fit.

Reply #10
Did you measure the base circles to see if there is a difference?
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

New engine combo and pushrods dont fit.

Reply #11
Havn't yet but I will.. I've got two stock camshafts to go off of..
One 88

New engine combo and pushrods dont fit.

Reply #12
somethings funky here,,
i thought stock lenght non roller was 6.9'' and the roller was 6.2x''.

New engine combo and pushrods dont fit.

Reply #13
The base circle of the comp camshaft is smaller..
One 88

New engine combo and pushrods dont fit.

Reply #14
one more time. :beatyoass:

call comp cams. they will tell you what push rods you need. ;)
gumby - beauty may fade, but stupid is forever!