ALLIS 175 VALVES

I posed this problem before a while back but couldn't find it again. So here it is again. When I first started looking at this engine it had four bent push rods. This happened after the head was replaced due to a supposed water leak on the head. No leak was found after testing the head so it was put back on. The valves were re done and new seats installed by the looks of them. Some valves are longer than others by about 1/16". So we put the rocker arm assy back on and backed off the adjusting screws all the way and when we turn the crank over by hand some of the are compressed to the max! and if turned any further it bends the push rods! What is going on here? Wrong valve springs too many coils? The pistons come to the top of the liner and the head is flat ( no compression chamber ) so how can the valves open on exhaust if there is no space there? By the way it's a 226 engine.

If you're opening the valves to the point of coil bind (stacked solid) and nothing else was changed, I'd be willing to bet the rocker shaft was installed with the short side between the shaft and the head. Take the rocker shaft off and turn the pedestals so the long side is between the shaft and head.

Edited by Brian Jasper co. Ia - 02 Dec 2016 at 4:51pm

The head measures 3 7/8" thick, what should a head for a 175 measure? Rocker arm pedestals that we have can only be put on one way as the flat base has to go toward the head. The other way around would be way too short and only a small area for the nut to hold them in place.

There are a couple of things here that need to be addressed. #1. You say you've just backed off all the rocker arm adjustment screws as far as they would go. If that is the case, you SHOULD have had plenty of valve lash, if you actually used a feeler gauge to readjust the rocker arm clearances. DID YOU USE A FEELER GAUGE TO DO THIS OR NOT?? If there was zero lash at the valves (after loosening all adjustment screws all the way), your machine shop must have installed valves that are too long. Think about it....same tractor....same push rods.....same camshaft......same rocker arms (???). Nothing has changed except the head and/or valves/or springs.

Even when the adjusting screws backed all the way off it still bottoms out the springs! Cannot even start adjusting anything. Four new push rods from Stiener the rest are originals. What is the length of the rocker supports supposed to be? Yes I agree nothing else was changed so my buddy says but, I cannot swear to it as I didn't take it apart.

Checked with the rebuilder and he say's no way, that's the head that was brought in! So we're stuck!!! How about putting a spacer between the head and the rocker supports? Like an 1/8" thick.

...I just did some eyeballing with a tape measure on an E combine head(should be the same thing).Has no rocker shaft. 3 7/8 thick(not quite).Top of retainer approx 1 7/8 from spring seat.Top of valve stem approx 2in from spring seat. From rocker stand pad to top of retainer approx 1 1/8. How does that compare to what you have?

Who's got rocker arm supports? None of the catalogs list them.

I think we'll just put some spacers under the supports and that'll be good.

The problem started when the neighbor took the head into the rebuilder to have it checked for cracks. They gave him the wrong head back, according to the casting number it is for a D15! So he goes back a couple of months later and they say NO WAY that happened ! the head fits on the block okay but, is obviously not right because it bends the push rods and the valves are totally compressed bending the push rods. The head is apperently an 1/8" thinner than the correct head. So we have too short rocker arm supports, thus the need for spacers.

My mistake, it's a D17  AM4659 CASTING # should be AM 4831 or AM 4472.

I think it's back to square 1. Was it running before it was taken apart, who did that work, and where did they go with the parts.
AaronSEIA