The Stovebolt Site Forums The Shop Area Engine Shop Head difference?

I have 2 heads from a 235 engine, and only need to have one machined.

The first one has a casting # 3835913

It shows some vavle quide wear especially on #6 cylinder.
Are the valave guides on this head pressed in or do they have to be machined out? It came off a 1955 engine

The other head has a casting # 3701887 and came off a 1953
235 engine. It seems to be in a little better condition but if I use this head I would be going backwards a couple of years in design.

Are they interchangable? Can I use the 1953 head on the 1955 engine if I have to?

Thanks,
Tim

Tim,

The 1953 235 engines were "odd balls", so it is best to check to see if the head-bolt patterns are the same. If they are the same, they are interchangeable (except the 1953 head will not have the four holes for the 54-62 valve cover).

Tim

TRK,

Don't know about the head differences, but make sure you ask your automotive machinist if those guides are candidates for knurling.

Stuart

What is Knurling?

TRK,

If guide wear is minimal, a special tool is run through the guide. The tool knurls, or raises a furrow through the ID of the guide which is then reamed to the exact size of the stem.

This procedure repairs the worn guide without the expense of sleeving or guide replacement ($$$). The 'furrows' allow oil to lubricate this stem/guide area better too.

Some folks look at this as only a temporary fix, but many automotive machine shops routinely do it...I had it done on my engine and it worked out perfectly.

I am just tossing out options to bushing or replacing your worn guides. Talk to your automotive machines about knurling.

Stuart.

Knurling valve guides is explained here.

I have had knurling done and had good long-term results (10K+ miles) and I have also had short-term problems (less than 2K miles). Stuart's advice is good but it relies on you finding a shop that does not mind replacing (or, putting bushings into) the guides. The easiest thing for a shop to do is to knurl the guides and get the head out of their shop. As I recall, the guides are a press-fit into the head.

I looked at knurling on youtube. Didn't know this was an option.

I will check into it but I have a feeling he will want to replace the guides.

Tim

Mine were knurled and they didn't last at all. I get the impression that the popular way to repair those guides is to machine and install bronze inserts.