Strange 292 head problem

[metro1]

I removed the heads from another engine and had them reworked at the machine shop. I was installing them today and ran into something I had not experienced before. On the drivers side head the top holes in the head do not exactly line up with the threaded holes in the block. The bolts drag against the front of the holes in the head. I tried it back on the old engine and the same thing. It must be bored wrong. The bolts will go in but the drag will make torqueing it incorrect. I am using ARP bolts which have a smaller shaft diameter except for the top 5/16 so they only scrape there. At this point I could shave a few thousands off of the top part of the bolts but I really don't want to do that. I guess I could open up the front top of the holes in the head. Has anyone ever ran into this?

[paul2748]

If you belong to Y-blocksforever.com I would run this question there if no one here can help you.

[55blacktie]

Metro, were the cylinder head guide pins removed from the block? If the pins were removed or replaced with the wrong pins, that could explain your alignment problem. I've read of head bolts being too short/too long after milling heads or using thicker/thinner head gaskets. The same can also cause alignment issues with the intake manifold, which can require either milling the intake or the intake side of the heads for proper alignment. However, I've never heard of milling/surfacing heads to cause alignment problems with the block. I suppose it's possible more was milled from one end/side of the heads. Try measuring the center pads near the spark plug holes on the exhaust side of the heads. The pads should be 1.010 for heads that have not been surfaced/milled. After measuring the center pads, compare the measurement to the end pads. If they are not the same, that could be your problem. It's not likely that a caliper will give a precise measurement. It's best to use a micrometer that's been calibrated. It might require a return trip to the machine shop.

[metro1]

The other head fits good. On this one the bottom (short bolts) are aligned good and go right in with no interference. It's the top bolts that all scrape the front of the holes on the head. It fits the same way on the engine it came off of. I removed the bolts with an impact so I don't know if they tight before or not. I assume both heads were done the same way at the machine shop . I can't figure why one fits good and the other doesn't. The old engine did have a blown head gasket so maybe it was bad already and didn't get torqued properly. None of the alignment pins were removed. There was a crack in one of my heads so I used these.

[55blacktie]

If you are not a member of y-blocksforever.com, you will not be able to post your question. You can, however, send an email to Ted Eaton ([email protected]). Ted usually replies within 24 hours. Ted can also explain to you the registration process for y-blocksforever.com.

[metro1]

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That's a good idea. I'll have to get with Ted and join up.

[KULTULZ]

Originally Posted by metro1

That's a good idea. I'll have to get with Ted and join up.

And come back here and post what you find. I am curious also.

[55blacktie]

Metro, I just reread your original post. Is it possible that the ARP head bolts are the problem, not the heads? There have been a number of complaints regarding the ARP rod bolts not fitting OEM Y-block rods; there isn't sufficient clearance for the bolt heads. A suggested fix has been to grind the bolt heads down for clearance.

Can you check alignment by using the original rod bolts?

[KULTULZ]

A suggested fix has been to grind the bolt heads down for clearance.

I would consult TED EATON before doing this.

[KULTULZ]

The bolts will go in but the drag will make torqueing it incorrect. I am using ARP bolts which have a smaller shaft diameter except for the top 5/16 so they only scrape there.

The bolt shank touches the cyl head hole before the hex cap reached that point?

[55blacktie]

Grinding bolt heads is in reference to the rod bolts, not head bolts. I've read that both Ted Eaton and John Mummert suggested grinding the ARP connecting rod bolt heads to provide rod-to-bolt-head clearance.

In Mummert's YouTube video on their H-beam connecting rods, the difficulty of finding connecting-rod bolts that fit OEM rods is mentioned.

[metro1]

With the washer installed there is 3/16 of the large portion of the shank below the cap that scrapes the side of the hole. I think I'll just open the hole in the area that causes the interference a few thousands with a die grinder and move on. I don't see where it will hurt anything and it will allow the bolts the turn freely.

[55blacktie]

I don't know how thick the casting is in that area, so be careful. I suppose there could be casting flash/residue that's causing an obstruction. There might be just enough difference between the OEM head bolts and the ARPs to cause the interference.

[metro1]

I have a picture of the problem. How do I send it?

[KULTULZ]

Originally Posted by 55blacktie

Grinding bolt heads is in reference to the rod bolts, not head bolts. I've read that both Ted Eaton and John Mummert suggested grinding the ARP connecting rod bolt heads to provide rod-to-bolt-head clearance.

My thought is that either the block deck and/or the cyl head itself has been wrongly angle cut.

If one goes to grind on the fastener, it may weaken it or if the fastener is found to be defective itself, you will not be able to return them.

The problem is on one side of the short assy. I would want to know how TED or JOHN interprets this before going neanderthal.

On the drivers side head the top holes in the head do not exactly line up with the threaded holes in the block. The bolts drag against the front of the holes in the head. I tried it back on the old engine and the same thing. It must be bored wrong. The bolts will go in but the drag will make torqueing it incorrect. I am using ARP bolts which have a smaller shaft diameter except for the top 5/16 so they only scrape there.

[KULTULZ]

Question and thread continued @ y-blocks forever.com -

- http://forums.y-blocksforever.com/Topic165303.aspx

I need to know the answer myself.

[KULTULZ]

A quick couple replies already -

TED wrote -

From the description you give for the friend’s cylinder head, it was resurfaced without care to ensure that the deck surface was square to the grinding or cutting tool when the head was resurfaced. If that is indeed the case, then the angle between the head surface and the intake mating surface will be different. If one cylinder head bolts down fine, then use that angle as a comparison to the deck to intake angle on the head that’s having a head bolt issue. Another telltale would be if the head bolt hole at the bottom of the head is not square with the deck surface of the head. A machined bar that fits the head bolt hole at the bottom of the head would help to determine that either with some layout dye or a square or a dial indicator. Several options there.

And then there is mention of the intake not fitting correctly as is.

[metro1]

Thanks Kultulz. I saw the replies on the other site. I contacted Ted today and he gave me a time to sign up tonight. It's not really off that much so I think I'll use the other guys suggestion and take out a little with a burr grinder in the affected area and hope for the best outcome.

[metro1]

image0 (4).jpeg All of the top bolts look like this. This is without the washers. They go in fine until they get to the top larger part of the bolt.

[55blacktie]

I would use a sanding roll instead of a burr grinder, being careful to only remove the amount of material necessary. check your progress frequently.