312 cam bearings, Isky e4 cam.

312 cam bearings, Isky e4 cam.

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By Mike. - 8 Years Ago

Hi. Anybody had trouble fitting an Isky E4 camshaft in a 312? Fitted new cam bearings into block ( Durabond F9A) and tried to fit new camshaft in. Would not even enter the bearings. Measured the cam journals on the E4 and they are 10 thou bigger thaan the old cam. Old cam goes in very easily and turns freely. Do I have a faulty cam or this normal for Isky?

By Dave V - 8 Years Ago

I installed one in a 57 312 3 years ago with no problems. Love the cam. Dave V

By 57RancheroJim - 8 Years Ago

I put an E4 in mine three years ago with no problem, can't imagine why yours is .010 larger?

By DryLakesRacer - 8 Years Ago

I'm lucky to be local, but call Isky in Gardena Ca. and tell them what you have. I know they make larger diameter journals and bearings for blocks that have spun them. They have always been ez to work with and if the cam is new they may just exchange it. If not redoing the journal surface is not that big of a deal. Good luck

By slumlord444 - 8 Years Ago

Line bore the bearings to make it fit? Seem to recall that this was standard procedure back in the day? Definitely had to do some minor fitting on the bearings on my 312 when I rebuilt it in 1968 and installed new cam bearings and a Crane cam.

By charliemccraney - 8 Years Ago

Did you try contacting Isky about it?

By Mike. - 8 Years Ago

Thanks all. Seems a little strange. I will contact Isky and see what the score is. It's a bit awkward dealing with the USA from here in the UK,, but I'll try and get through to somebody 😀. I could turn the cam down but I really shouldn't need to.

By Ted - 8 Years Ago

Mike. (6/10/2016)

I’ve dealt with a lot of Isky cams and never had one that wouldn’t fit the stock cam bearings.

By the book the cam bearing journals are expected to be 1.926 ±.0005”. I checked a new Isky Y camshaft I had sitting here and it falls to the low side of that spec (1.9255”) so no problem there. I do keep cam bearings in stock that are 0.010” undersize (oversize depending upon your perspective) which requires the cam journals to be turned down. Those undersized cam bearings are clearly marked with a special suffix on the part number though. Is there a chance you are dealing with a set of 0.010” undersize cam bearings? What are the journal diameters on the new Isky camshaft you have?

By Mike. - 8 Years Ago

Hi Ted. I bought stock bearings from Mummert. I didn't check the size. I installed them and the old stock camshaft slid in easily so I think the bearings must be stock. I cant measure the cam journals right now as the cam is at my workplace, we did measure it yesterday but I can't remember what it measured.

By Cliff - 8 Years Ago

Hi, I had the same problem (still have), the old cam was worn and fit the bearings, however the new one would not even start, I am going to remove the cam bearings and try another set, my cam is a Howards ground on a CWC blank, I think the bearings may have been oversize and I did not read the box.

By Mike. - 8 Years Ago

Just measured cam journals at exactly 1.926, so it must be the cam bearings that are the issue. I have ordered some more bearings, hopefully this will solve the issue. Thanks everyone 😀

By Florida_Phil - 6 Years Ago

I built a 312 years back. The motor was a stock D code out of a 57 Retractable. When I had the block hot tanked the machinist installed new cam bearings. I was told Isky was the cam to use. I called Isky and they connected me with the old man himself. I told him what I had and he sent me a cam. The cam was very tight in the bearings. I could turn it with a wrench, but not something that I wanted in my engine. As I recall I had to work over the bearings with emery cloth to get the cam to fit correctly. I have been told this is common with Y Blocks. You may have to align bore the cam bearings. Talk to your machinist. Not all machinists are knowledgeable on these old engines. Modern parts don't always fit.

As a side note. I don't know what cam old man Isky sent me, but it was killer. The motor ran pop up pistons, three twos on an Edelbrock manifold and headers. It blew the cogs off the cluster gear right out of the box.

By paul2748 - 6 Years Ago

I had an Isky cam put in the new engine I had built. The builder said the cam would not go in all the way so he had to align bore the bearings.

By slumlord444 - 6 Years Ago

When I first rebuilt my 312 back in 1968 I had problems with the cam being tight with new cam bearings. As I recall used 600 wet sandpaper with kerosene for a lubricant and removed just enough material to make it turn easily. Same bearings still in it after two rebuilds and two new cams. No issues.

By Dobie - 6 Years Ago

It's not enough to hack the elections, now they gotta hack us, too? SHEESH!

By 2721955meteor - 6 Years Ago

paul2748 (6/3/2018)install the old cam.and where it is snug giv it a smac with a hard wood block onto the cam lobes.

, if that does not work, i have a used cam with ground in slots, rotate as you push the cam in if minor cuttings are required to get the new cam in you will be ok

in my exp. when the cam won't go into the new bearings the bushings are not aligned. 2 ways to address is which bushing is restricted,
if this does not work then go back to who installed the bushings and take your new cam,leave the solution to the machine shop

By Dave C - 6 Years Ago

2721955meteor (8/12/2018)

paul2748 (6/3/2018)Install the old cam and where it is snug give it a smac with a hard wood block onto the cam lobes., if that does not work, I have a used cam with ground in slots[ rotate as you push the cam in if minor cuttings are required to get the new cam in you will be ok

in my exp. when the cam won't go into the new bearings the bushings are not aligned. 2 ways to address is which bushing is restricted
if this does not work then go back to who installed the bushings and take your new cam, leave the solution to the machine shop

I have used this solution in the past, it works. Last time I installed my own cam bearings I used some 320 sandpaper and cleaned up the bearing bores before installing the bearings. Worked like a charm, cam turned smooth afterwards. Maybe just another solution.

Dave

By Florida_Phil - 6 Years Ago

I asked my current machine shop about this issue. This guy has years of experience with Ford motors. He told me to never use sand or emery paper on cam bearings. The grit gets into the engine and is hard to remove. He told me new cam bearings need to be fitted to the cam when the engine is being machined. I have never had a problem fitting a new cam into an old engine. It always seems to be after new cam bearings are installed.

By KULTULZ - 6 Years Ago

"This guy has years of experience with Ford motors. He told me to never use sand or emery paper on cam bearings. The grit gets into the engine and is hard to remove. He told me new cam bearings need to be fitted to the cam when the engine is being machined."

Correct You don't want abrasive(s) in an engine, especially a fresh build.

Usually, when a block is being machined, the cam bearings are taken out before submersing in the tank and when the new bearings are installed, the cam is inserted to check for fit and then align-bored if necessary.

By Ted - 6 Years Ago

Phil has it right. Putting a camshaft in the old bearings typically does not present an issue. But new rebuilds and especially if the blocks are caustic washed, requires new cam bearings. It’s the installation of these new cam bearings that brings camshaft installation issues to the forefront. Unfortunately it’s not the cam bearings themselves that are at the root of the problem.

Two different things are happening here when the camshaft doesn’t go in freely. One is that the cam journal holes are on the small side which then causes the bearing I.D. to be undersize once they are installed. It’s recommended to measure the cam journal holes before installing the bearings to insure that the hole size is in spec and if undersize, then work on the O.D. of the bearing so it does not ‘crush’ inwards thus creating a bearing that’s too tight to the cam journal. I recently worked on a 1955 Mercury ECK 292 block where four of the holes were 0.004-0.005” undersize but the center hole was actually at spec. Go figure on that one but four of the cam bearings had to be worked on before installing them.

The other issue is cam tunnel hole alignment. This is a frequent problem on the 312 engines as they were machined on a different machining line versus the 272 and 292 engines. For reinstalled cam bearings, many machine shops will simply use a ‘bearing’ knife to work on the misaligned bearings until the camshaft slides in. For checking cam tunnel bore alignment on the Y engines, I use a machined steel bar that can be slid into place to verify both the hole I.D. dimension and the alignment of the bores. The out of alignment bore holes are a difficult fix without carving on the installed bearings and one option is to simply rebore the cam tunnel holes to the 1954 239/256 size and making new cam bearings. The ’54 cam hole size is selected as this is the next cam plug size that’s available.

If it’s any consolation, the problem with cam hole sizing is not restricted to just the Ford Y. I find it in other non-Ford engines also.

By Dave C - 6 Years Ago

Florida_Phil (8/18/2018)

I don't sand the bearings.
I said the bore in the block.
I've been building all makes of engines for 50 years, I figure I've learned a few things during that time..

Dave

By Florida_Phil - 6 Years Ago

Dave C (8/18/2018)

I don't sand the bearings. I said the bore in the block. I've been building all makes of engines for 50 years, I figure I've learned a few things during that time.. Dave

I'm sure. Some people on this forum have never built an engine. I've seen some pretty strange things too. A neighbor of mine sand blasted an intake manifold and bolted it on his engine without cleaning the sand out of it. His motor lasted about 10 minutes.