So I’m working on my flathead getting ready to cut the seats and when I install one of the guides into the guide bore it is extremely loose. This is only on one guide bore and it is the same with all the other guides. Just that guide bore is bigger. Anyone know a quick fix. I was thinking of a extremely thin sleeve to put around the guide to take up the room but I want to hear what you guys have to say. And btw this is a original guide since it is still tight around the valve and will not need replacing. Thanks, Boden Sent from my iPhone using H.A.M.B.
Go to Caterpillar and but a bottle of bearing mount. its something like loctight. made for mounting a race back in a housing after a bearing locks up and spins the race in the housing. You can also take a sharp punch and knurl the block a bit.
the only problem is is that the hole is so big that i can move the guide a 16th of an inch in the bore. i don't know if i can get the guide centered in there enough to put the bearing mount in to hold it in place.
You could have a guide made in whatever size needed, but the worn bore for it will certainly not be even and true.
Ream the hole in the block round , turn an oversized guide bushing press it in the block ream it to valve size and wish it well
This is probably the best way to fix it. If you can get the block squared up on a Bridgeport table and indicate the guide bore, even better. Then you can bore it providing you have a decent boring head. A reamer only follows a hole.
Its not necessary for the guide to be perfect . what is necessary is for the valve and the seat to fit to make a perfect seal. so get a oversize guide made get it solid in the block. and cut the valve seat to center up with the valve. you might have to cut away the existing valve seat and install a hard seat? Me I would take a sharp punch and give the guide a good peppering till its snug and epoxy it in place. set the valve guide spring and retainer all in place before the epoxy hardens. remember all that's necessary is for the valve to make a seal.
I didn’t know that they make oversized guides. Do you know who does this. Or is there a website I can go on? Sent from my iPhone using H.A.M.B.
You guys who are talking about oversize guides keep thinking the bore wore out exactly round. Does anything ever do that? First he needs to chuck that block up in a mill and make that hole round again. Then he might as well press in a bushing, and ream it out to the proper size to use the good original guide.
What was the guide like that you removed ? Was it loose or tight in the hole. Maybe someone already machined it for a larger guide rather than just wear. Hard to believe the hole could wear that much, so I'm wondering about previous machining. First choice is to search for an oversize guide. You might be able to get something from a different type of engine and have it machined to fit. You also need to check the existing hole to see if its reasonably round or just worn to an odd shape. Give us a few more details and we'll try to help. Maybe a couple of pics.
The bores for the guides are not perpendicular to the deck on the flathead, and actually they are different to side. The p***enger side is laid down roughly 3 2/3* from the engine centerline and the drivers side is 6 1/3* down. Are you sure the worn bore is almost 1/16” oversize?
When I was 16 I bought a 46 ford bob truck. It had a stretched frame and long bed a br*** tag on it from some company in Oakland calif that did the fream & bed It had a sears rebuilt 53 flathead engine. and it idled perfect. at anything above a idle it had a miss. I found the Retainer clip that holds the valve guide ***embly has come loose. This truck had been driven all the way from Calif with that loose ***embly. it had quite a bit of guide to block wear. I just coated it with permatex & installed a new retainer clip and it was Ok.
Some of the "cobblers" here are going to scar this guy for the rest of his life! I get it, he needs to learn things but he needs to learn the right way to do them. I'll go out on a limb and say this isn't the backwoods where there aren't "professionals" within driving distance, the guy already has a problem, don't help him create a bigger mess than he already has. I'm all for him learning but more often than not many homebrewed money saving concoctions end up costing you double in the end.
Post your question over on The Ford Barn, someone will know how to fix it. Lots of knowledgeable folks over there.
When the flathead gave up in my 46 ford. I bought a adapter from JC Whitney and installed a 61 ford 352 two bbl engine. I could then smoke the 750 x20 rear tires.
Is the bore round? I'm trying to get my head around how a valve guide bore could wear if the guide keeper same out the guide would simply push up and the valve would not close. This might help
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