BOSS 302 block need help!!!!!!!!

[DAVID GAGNARD]

I have the new BOSS 302 block from Ford Performance and I am re-assembling my 331 cu in race motor.......everything has gone together as expected, except when it came time to bolt the heads on (AFR 185's)......I already had the Fel-Pro head gaskets AFR advises to use with these heads, but that will NOT work, seems the BOSS 302 block needs the 351-C head gaskets, not a big problem , just order some more head gaskets.....

But the instruction sheet with the block, says and I quote:

" Check cylinder heads for proper steam-hole aligment.Stream holes are designed to reduce the possibility of steam pocket formation. Due to the large number of aftermarket heads that can be used on this block, you will have to check this and modify as necessary". end quote...

The Ford Performance Tech Line is a joke, they act as if everyone is stupid and every question is a waste of their time... An e-mail to AFR said:

"Hello David,

You need to get the gasket to mark the holes you need to drill in the head, they are referred to as steam holes in between the cylinders. ..

o-k, they responded very quickly, now for the $64,000.00 question, which are the damn steam holes??????????? I'd rather not ruin a brand new set of AFR 185 heads drilling holes in them in the wrong place...........

here are a few pics, I am assuming the pic with the head gasket on shows the "steam holes" between the cylinder walls closest to the center of the block????

Any advise on drilling these holes will be greatly appreciated......Size/depth??????






Well, those pictures did not upload for some reason, please go to my gallery and you'll see what I mean, they are the first four pictures..........
David

(David - fixed your picture links for you....ron/CW)

[Rick Parker]

Dave: Your pictures are not showing up, however the steam holes are generally located directly above the top of the bore,(high point in the block water jacket) usually 1/8" or 3/16" diameter. They will corespond with the holes or slots machine in like area of the head. I think AFR has a machined slots to allow for various hole locations in different vintage blocks.

[computerworks]

David...I fixed the pic links in your post

[DAVID GAGNARD]

Ron, thanks a million, I owe ya.............

David

[Ronbo]

Here's an original Boss 302 head: Boss 302 Engine Cylinder Heads Photo

As I recall the "steam holes" were the ones closest to the bore to bore contact area. (two closest hot parts)

Hope this helps.

[DAVID GAGNARD]

Originally Posted by Rick Parker

Dave: Your pictures are not showing up, however the steam holes are generally located directly above the top of the bore,(high point in the block water jacket) usually 1/8" or 3/16" diameter. They will corespond with the holes or slots machine in like area of the head. I think AFR has a machined slots to allow for various hole locations in different vintage blocks.

Rick, Ron fixed the pictures, please look and advise me........

I did check over the AFR heads and they have a smiley face looking curve milled in the heads with what I assume to be the steam holes drilled in them... the curved area would accomodate varouis steam hole locations in varouis blocks, I think????

If this is correct, then my heads should be ready to go, but AFR advises to put the head gasket on the head and be sure the head has the steam holes to match the gasket, which I plan to do anyway.......once I get the correct gasket, the gasket on the photo was a used Fel Pro for a 302/351-W I used to check the piston-to-vavle clearance, not the correct 351-C head gasket, although they are supposed to be the same thickness compressed.....

david

[DAVID GAGNARD]

O-K, just went out and checked the block AGAIN......looking at the second picture down, there is a small hole,probably 3/16ths on each end of the block at the top(near the lifter galley), I'm assuming these are the "steam holes" that the bulletin is refering too???????hopefully!!!!!!!!!!!!!!!

If so, then I'm o-k as the AFR heads do have corresponding holes in the heads that lead to the water jacket......


Also, looking at the same picture, you will see 3 holes in a triangular shape around each head bolt hole,these are water jacket holes and when looking into them with a flashlight, you can see the light from the any of the holes as they are connected by a large passageway.......should flow more water thru the block.....

I also checked my OEM 1969 302 block....it only has one water jacket hole by each head bolt hole, these holes are to the center of the block, so the BOSS 302 block has 12 more water jacket holes leading from the block to the head than a standard production block!!!!!!!!!!!!!!!!!!

BTW: a few things they DO NOT tell you when ordering/buying this block is it uses 351-W size main cap bolts and your 302 windage tray bolts will not work on this block if using a windage tray, SUMMIT/JEGS sells the four studs you need for the paltry sum of $45.00!!!!!!!!!! also, the water pump bolts that go into the block are the larger 351-W bolts, so your 302 stuff doesn't fit there either.....

When I went to order a block, I tried to get the "older" A-4 block, it is discontinued and no longer avaliable and no one had any left in stock, everyone told me the BOSS 302 block is a DIRECT replacement 302 block, not quite true as I found out......NO mention of any kind on the appropriate head gasket either, so now I've got a nice new set of Fel Pro ($75.00) heads gaskets I can't use.........

All in all, I do like the block, when put along side a factory block, there is NO comparison, the new block is also approx. 30 pounds heavier... the front and rear surfaces are machined on this block as compared to "cast" on a factory block.....when looking at the amount of machining this block has, I can see why it costs what it does!!!!!!!!!

David

[J Persons]

There was a post on FFCobra a couple of weeks ago about a guy that ruined a set of heads when he drilled the steam holes. It seems that the holes he drilled for the end cylinders entered the exhaust ports and when he tried to fill with coolant, it started running out the exhaust ports. Personally, I would seek the advise of someone like Gordon Levy or someone else that is knowledgeable with this design before I started drilling the heads.

[Rick Parker]

Dave: the holes on the ends are indeed the steam holes, as long as they line up with those in the head you are good to go.The gaskets that you intend to get, be sure they match the heads, the water transfer openings (not to be confused with the steam holes) at the ends may be different. Look at the surface of an OEM Boss head to get an idea of any differences.

[DAVID GAGNARD]

Thanks to all for the help and info.........

Rick;
Checked everything out and it all looks good to go.......the only difference I can see in the 302/351-W head gasket and the 351-C head gasket is the C gasket in a little larger on the bottom of the block to match the extra water jacket holes in the block..The W gaskets do not cover them completely and would have a major water leak from the word go....

I put the C gasket on the block and everything matches up perfectly, then turned the head upside down and put the gasket on the head and it matches up perfectly there also..... marked the steam holes on a gasket on the block and they line up perfectly with the steam holes on the head, so I should be good to go.......

Thanks to AFR for having the forsight to do this on their heads.....saves me a lot of trouble and worry about having to drill a brand new pair of heads............

BTW: I checked my 69 302 block and it DOES NOT have steam holes..........

David

[Rick Parker]

Isn't it nice when the manufactures all colaborate.

[mikeforte]

Hi,
I've built a few new BOSS blocks. The steam holes that I know of are the between each of the cylinders in an "X". If you look between the #1 & #2 (between all cylinders too) cylinder there are triangular shaped holes that will expose the steam holes that will cris-cross about 2 inches down. No drilling or machining is needed.
These steam holes limit the max bore size because the limit the material between the siamesed bores.
I hope this helps some.

[DAVID GAGNARD]

Mike;

That's what I thought also at first, but look at the first picture in my post and you'll see a very small (3/16 maybe) hole on either end of the block just inside the head bolt hole,that is also a "steam hole"....that's the one I was worried about.....OEM factory blocks, at least the early ones I have do not have these holes.......

My heads do have the holes that line up with the small outer hole on the block....

BTW: what head gasket (part #) did you use on the BOSS 302 builds?????
Thanks;

David

[mikeforte]

Hi David,
The engines I built were actually BOSS 302's with Cleveland heads. I'll look more closely at the vintage BOSS block and new BOSS block and see when I get back in.

[DAVID GAGNARD]

Thanks Mike..............

David