Q: Push rod tube sizes for new AMC 1.7L heads

[poundman]

My original engine and heads where from a CB engine (72). I purchases new AMC heads. From other threads here I have read that later years switch the size of push rod tubes. Old ones are not available but newer version is part number 021109335C

Question, with the new heads should I be using the newer size push rod tubes. I am getting some leaking from a few on the head size, but that could be a pinched o-ring. Just seeking advice. I have asked the vendor also.

https://aapistons.com/products/new-amc-1-7l-type-4-aircooled-cylinder-head
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Restoring a 1972 Bay Window Bus that has not be registered for the road since 1981.
Sugar Land, Texas

[raygreenwood]

Maybe I am wrong...but there are two sizes of pushrod tube for type 4.

Early...and I mean really early like not imported to the US except maybe through Canada as a gray market car....

Very early 411 cars 021 109 335 A ...Used from beginning of production in 1968 up to engine # Z 0 009 406 (1.7L)
up to engine # W 0 057 034 (1.7L)

Anything after those two used the later/larger diameter PR tube.
Part # 021 109 335 B
From engine # Z 0 009 407 (1.7L)
From engine # W 0 057 035 (1.7L)
From engine # EA 0 000 001 (1.7L)

I could have sworn just a month or so ago I posted the dimensions somewhere in the bay window forum of both early (small) and late (larger) pushrod tubes. Both are still on my desk.

Wait...here is the thread

https://www.thesamba.com/vw/forum/viewtopic.php?t=805715&start=0

Ray

[poundman]

[Willin]

Are you hinting that you got it running?
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73 bus. Org. 1700 with dual Weber 40 idfs, bus header with Empi qp muffler, CB magnaspark 2 " ready to run kit".

[poundman]

[poundman]

I think I have figured out my problem. Tube size seems fine and I have the correct seals but bad installation. The other thread indicate there is 4mm thick version that might be better than the 3.5mm version. I might try to find them.

Anyway, you can see how I pinched them when installed. When I reinstall I will use some of that PTFE Teflon sealant just on the head side. I will also make sure to use the rotate while pushing in technique next time. And I will by several extras just in case.

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Restoring a 1972 Bay Window Bus that has not be registered for the road since 1981.
Sugar Land, Texas

[lil-jinx]

put a slight radius on the bore to dull the edge,a film of engine oil might help.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=620186
https://www.thesamba.com/vw/forum/viewtopic.php?t=668799
1974 Bay Westfalia. she likes to be called Ethel.
1968 Dune Buggy sold dec 2024

1974 parts bus
A smart man learns from his mistakes,a very smart man learns from other's mistakes.

[poundman]

Reporting back that I think I have successfully fixed the problem. Everyone of those seals on the head side were pinched and cut. I used the thread sealant with (T-2) on the head side seals. Just a little light coat, and the used a 11/16 socket to push while turning. The popped right in with ease. Unlike the first time that was super hard. First time I used some oil. The seals looked exactly the same, but the new ones must have been more pliable. I ran the engine for about 5 minutes to test and no leaks !

I seem to have slight leak around the dipstick tube where the rubber piece connects the case with the fan shroud. It is a new rubber but still leaking some. It is a very tight fit to reach it but I think I can put some kind of sealant around it, maybe some right stuff. I hear that is pliable also.

Well at least one problem solved on to more restore items. Thanks for the help and advice.
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Restoring a 1972 Bay Window Bus that has not be registered for the road since 1981.
Sugar Land, Texas

[Bnanwel]

Nice! It feels great, right? Diagnose it; fix it; check it off the list.
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‘72 Karmann Ghia Conv.
‘73 Karmann Ghia Coupe
‘74 Karmann Ghia Coupe
‘70 Deluxe
‘72 Deluxe

[poundman]