High compression head

[Tom Endy]

Many of you may be aware that most every supplier in the country is out of stock of Snyder 5.5 high compression heads. I checked with most of the better suppliers and I am hearing several month before new stock will be available. One engine builder in Illinois I spoke with was very disenchanted as he is not able to deliver a number of engines he has orders for and it is affecting his cash flow.

I have been told there is an old article around written by the secrets of speed folks that was written before high compression heads became a marketable item, that says you can take a stock head and mill off 5\32", and if you have a 60 over bore you will have close to a 5.5 head.

My question is: How do you tell if a head has ever been milled? There must be a measurement of the distance from the bottom of the head to the distributor boss for a stock unmolested head. Does anybody know what that measurement would be, and is the machined surface of the distributor boss a contstant measurement?

Tom Endy

[CA Victoria]

Tom,
Stock head thickness is 2.25" measured at the distributor pass thru. I beilieve the piston reliefs were .080.
I just bought a used 5.5 from east coast......didn't know they are so scarce.

[acenewman]

I got a Snyder 5.5 head about a week ago. You need to call and get on the list. When they get them they ship in the order of folks on their list.

[George Miller]

Originally Posted by Tom Endy

Many of you may be aware that most every supplier in the country is out of stock of Snyder 5.5 high compression heads. I checked with most of the better suppliers and I am hearing several month before new stock will be available. One engine builder in Illinois I spoke with was very disenchanted as he is not able to deliver a number of engines he has orders for and it is affecting his cash flow.

I have been told there is an old article around written by the secrets of speed folks that was written before high compression heads became a marketable item, that says you can take a stock head and mill off 5\32", and if you have a 60 over bore you will have close to a 5.5 head.

My question is: How do you tell if a head has ever been milled? There must be a measurement of the distance from the bottom of the head to the distributor boss for a stock unmolested head. Does anybody know what that measurement would be, and is the machined surface of the distributor boss a contstant measurement?

Tom Endy

It is not worth the effort to mill a stock head that much. I have done it years ago when there were no H C heads available. The problem is combustion chamber shape

[James Rogers]

I will have some next week. I got on the list 3 months ago.

[Kurt in NJ]

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I measured a new later production head --has a diamond under the waterpump boss

thickness at stud bosses -and dist boss --2.234
depth of counterbore over piston --.115--.117

[James Rogers]

Originally Posted by George Miller

It is not worth the effort to mill a stock head that much. I have done it years ago when there were no H C heads available. The problem is combustion chamber shape

I agree, George. I have one I bought at Hershey years ago in my more ignorant days and found it to not have any more compression than a stock head. I might post some pics here tomorrow after I get back from the mountaineer show.

[V4F]

i have a 5.5 head with .060 milled off . 6-1 now .

[Mitch//pa]

is the snyders 5.5 head the same one that bratton sells ?? brattons calls theirs a police head
thanks

[Marco Tahtaras]

Originally Posted by steve norcal

i have a 5.5 head with .060 milled off . 6-1 now .

What did the chambers CC after milling? I would expect 159cc on average which would be 5.82:1 on a standard bore engine which is getting close.

Originally Posted by Tom Endy

I have been told there is an old article around written by the secrets of speed folks that was written before high compression heads became a marketable item, that says you can take a stock head and mill off 5\32", and if you have a 60 over bore you will have close to a 5.5 head.

The original unmilled heads I've checked had counterbores measuring .093" deep on average. I wouldn't run a head without a counterbore as it doesn't leave much clearance. The standard piston protrusion was .031" so if you had the block decked .009" the protrusion would be about .040"

[Tom Endy]

Originally Posted by Mitch//pa

is the snyders 5.5 head the same one that bratton sells ?? brattons calls theirs a police head
thanks

Bratton's 5.5 head is a Snyder head. I believe Snyder is the only one making a high compression head. I don't think a Brumfield head is currently being marketed.

Tom Endy

[bettlesr]

You might try Red's Headers in CA. I got a 7:1 aluminum Winfield head from them not too long ago. They had both 6:1 and 7:1 at the time.
Dick

[Mitch//pa]

Originally Posted by Tom Endy

Bratton's 5.5 head is a Snyder head. I believe Snyder is the only one making a high compression head. I don't think a Brumfield head is currently being marketed.

Tom Endy

thanks tom

[Tom Endy]

I spoke with Walt Bratton this morning. They are still out of stock of Snyder 5.5 heads. I am on their waiting list. From the responses to this post I don't think I will persue milling a stock head.

Walt tells me they had a recall on the Snyder 6.1 heads due to the distributor and lug bosses being too high.

Thanks to those that responded.
Tom Endy

[Mitch//pa]

i have a 5.5 i bought from brattons that i used for 500 miles and took it off. i dont want it anymore i guess ill list it on ebay unless someone wants it ......

[Dave in MN]

I just received shipment of (3) 5.5 heads from Snyders late last week. James is correct on the waiting list. I have been on the same list for 3 months. The new production of the 6:1 should be arriving soon. I have been on that list for 3 months also.
Have a good weekend all!

[30ccpickup]

Originally Posted by Tom Endy

I spoke with Walt Bratton this morning. They are still out of stock of Snyder 5.5 heads. I am on their waiting list. From the responses to this post I don't think I will persue milling a stock head.

Walt tells me they had a recall on the Snyder 6.1 heads due to the distributor and lug bosses being too high.

Thanks to those that responded.
Tom Endy

Who do we contact for the recall?

[Tom Endy]

Originally Posted by 30ccpickup

Who do we contact for the recall?

I would start with the place where you bought it.

Tom Endy

[Not George]

Originally Posted by Mitch//pa

i have a 5.5 i bought from brattons that i used for 500 miles and took it off. i dont want it anymore i guess ill list it on ebay unless someone wants it ......

What don't you like about it?

[Terry, NJ]

, Why'd ya take a good HC head off? On the face of it, it seems wrong. You must have had a good reason.
Terry

Originally Posted by Mitch//pa

i have a 5.5 i bought from brattons that i used for 500 miles and took it off. i dont want it anymore i guess ill list it on ebay unless someone wants it ......