Push rods contacting head

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JayBayBay
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Push rods contacting head

Post #1 by JayBayBay » Tue Aug 07, 2018 7:19 pm

Hey everyone, finally getting around to finishing up my engine and when I went to adjust my rockers i noticed there was barely any
clearance between the push rod and bore of the cylinder head. looked at a couple others and they were even contacting. I've got an 200 with the aluminum head and the 1.6 factory style adjustable rockers. It seems as if the rocker itself is not long enough to keep the push centered in the bore or the bore was not machined big enough. I took the rocker assembly back off to inspect and didn't take any pictures but there are marks on some of the push rods from touching.

Anyone run into this problem before?

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Econoline
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Re: Push rods contacting head

Post #2 by Econoline » Tue Aug 07, 2018 11:19 pm

I'm pretty sure this has come up before and recently. There's a clearance problem with the pushrod holes, or some of them. I'm sure someone will chime in. If you do a search you'll find the recent thread on that issue. You'll have to clearance them one way or another.
How is the geometry otherwise?
It ain't gonna fix itself

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Gene Fiore
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Re: Push rods contacting head

Post #3 by Gene Fiore » Wed Aug 08, 2018 1:49 pm

Oh yes...the pushrod bores are not machined properly. :bang: I had this same issue and decided to manually fix the pushrod bores myself. I mocked it up installing all the pushrods and rocker assembly. Then carefully marked the casting area around each pushrod bore with a sharpie where the pushrod was touching. Then pulled it all apart and removed the head(I used an old head gasket for this process). I don't have a dremel so did it the old fashioned way with a long round hand held file with the head positioned on my workbench just overhanging so the file could go completely thru the bore and out the bottom side. Filed out the areas I marked with the sharpie while intermittently using my shop vac to carefully remove any filings from the head. I also covered the valve spring areas to avoid getting filings anywhere near them. I think it took me about 15 minutes per bore initially...then of course re-mock up everything to re-check the clearance and do it all again until I felt there was enough clearance...whew! Glad the aluminum head is light! I still haven't fired up the engine yet as I don't have the carb installed with a new throttle cable setup yet...hopefully will have that done in the next few weekends. Keeping my fingers crossed everything works well.
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chad
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alu head frm Oz sold localy 2 fit 'our' i6

Post #4 by chad » Wed Aug 08, 2018 10:09 pm

"...didn't take any pictures but there are marks on some of the push rods ..."
"...the pushrod bores are not machined properly..."
Boy, now U both mention it I'd luv ta C pic (B4'n after or just B4).
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

JayBayBay
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Re: Push rods contacting head

Post #5 by JayBayBay » Fri Aug 10, 2018 3:49 pm

Thanks for the replies, I'll be pulling the head off soon and creating the clearance needed. I already took the rocker assembly off but ill take a pic to show how the push rods were contacting and an after pic once I'm all finished!

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65coupei6
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Re: Push rods contacting head

Post #6 by 65coupei6 » Mon Aug 13, 2018 2:11 pm

I guess I was lucky. No problems with the larger custom 3/8 push rods. So far I have around 800 miles on the rebuilt engine. I will pull my valve cover soon and check for marks on the rods.
...Marco

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JayBayBay
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Re: Push rods contacting head

Post #7 by JayBayBay » Wed Aug 15, 2018 7:47 pm

So finally got around to making clearance for the push rods, I already had the head off but in the first picture this is what the rod looked like when it was making contact.

Image

I should've disassembled the head before grinding to save myself the extra cleaning hassle. I ended up having to take more away than this next picture shows. Some of the bores ended up not needing much at all but a couple I almost went halfway down the bore.

Image

That same night a gopher tortoise crept into the garage and scared the crap out of me!

Image

Hopefully not too many others have this issue with their heads.

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chad
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Re: Push rods contacting head

Post #8 by chad » Wed Aug 15, 2018 10:39 pm

aaahahahahaaaa
"...this issue with their heads...'
yeah poor turtles F^#>ed Up by these earth changes frm "climate change".
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

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