Vintage 302 chevy.

Loves302Chevy said:

View attachment 8496

I read that you must grind these cooling passages deeper to maintain coolant flow on excessively milled heads.
Just 1/16" ought to do the job - compensate for the amount of material removed from the deck surface.

Click to expand...

Do you think that will work? The sparkplug cooling holes have been welded completely shut. Grinding the groove now I wouldn't think would be much of a benefit because the water wouldn't flow. This has been one of my areas of concern on these heads as there isn't much talk about what to do after the holes have been filled. There are different points of view everywhere its talked about, you need them vs. you don't need them. I myself would like to have at least the exhaust side cooling hole BUT I have no idea how or where to redrill it or if I would trust the machine shop to do it. I guess I could talk to them about it but as time goes on there aren't to many people(machine shop wise) that have a clue how to modifiy these old heads whether they are really good or not.

Here's what I could find about it below.

As Told By Grumpy Jenkins:
"If the head is angle-milled very severely, the spark plug cooling holes may have to be filled and redrilled further outboard on the head. This isn't too critical on the drag racing heads as it is certainly possible to run the heads for a short time with no plug cooling at all. However, it would be smart to have at least the exhaust-side hole open if this is possible. There is plenty of material on the 492 head to move the cooling holes out a considerable distance. There is less material in this area on the 292 head. It is possible to break through the outside of the head when drilling the holes outboard of the stock location. A Grand National or short-track engine must have the exhaust side plug cooling holes in functional order to prevent detonation."

Here's another view of my head in better light. You can see how far down the heads were milled just by looking at the welds

I have never heard of welding those shut. But I believe the quote from Jenkins.
Personally, if you plan to drive this on the street, I would think that you NEED the coolant flow there.
Not just for the spark plug, but for the exhaust valve.
Were the heads angle milled? If so, you obviously know that your intake manifold will have to be machined to match the new angles.
Too bad you don't have access to an EDM machine. Otherwise, it's going to be a dremel with the right bit and a very steady hand.

These were on a complete race engine that I bought, nothing has been changed other than replacing parts. They welded the holes shut because of the angle mill, without welding them the sealing ring on the gasket would be right on the edge of that hole. There is room to drill those holes further outboard as bill jenkins suggested but the machine shop was hesitant. If they're going to get drilled I guess it will be my doing.

those holes when drilled in the outer location are usually drilled at about a 45 degree angle, towaed the valves and combustion chamber rather than vertical, so as too have the inner lower opening of the new drilled hole closer to the cylinder heads internal coolant passages.
look carefully at the block and gasket before drilling any steam or coolant holes as they don,t do any good unless they allow coolant to freely pass from the block, through the head gasket and into the cylinder head coolant internal castings coolant passages. most machine shops have a milling machine that will do this precisely as to location, depth and hole diameter for a minimal charge if your not comfortable doing it and taking a slight chance of ruining a cylinder head
especially if you try to free hand drill those holes with a hand drill.
this would not be hard on a full size drill press with the correct adjustable table and vise, but those are not too common in home garage shops



related info
http://garage.grumpysperformance.co...steam-holes-posted-by-dennyw.2991/#post-57455

http://garage.grumpysperformance.co...needs-clean-up-equalization.12474/#post-62647

http://garage.grumpysperformance.com/index.php?threads/thoughts-on-cooling.149/#post-58196

http://garage.grumpysperformance.com/index.php?threads/head-gasket-related.1859/#post-50617

http://garage.grumpysperformance.com/index.php?threads/sbc-head-gasket-choice.11070/#post-49297

http://garage.grumpysperformance.co...r-piston-dome-or-port-volume.2077/#post-60554

http://garage.grumpysperformance.co...oving-gaskets-the-wrong-way.10464/#post-43962

http://garage.grumpysperformance.com/index.php?threads/porting-can-help.462/#post-2833

http://garage.grumpysperformance.co...olishing-combustion-chambers.2630/#post-50238



http://www.aa1car.com/library/gasket_failure.htm

Grumpy I messaged joe sherman over on speedtalk and he suggested to drill 7/16 holes in the block deck between the center cylinders and forget the spark plug cooling holes. Just like arrow 1 indicates below. This will allow the coolant to flow right up under the center exhaust ports.

Damn, angle milling those heads puts the head gasket seal really, really close not only to the cooling passages, but the head bolt holes as well.
If it were me, they might be ok for drag racing, but I would not use them for street use. Personally, I would go with another set of heads.

It would be nice to have a set of dart or afr heads but by the time I pick up a set and all the parts for my application it would almost be double what I have in these heads. Maybe on the next engine I'll invest in a set. Street driving won't be a normal thing if it does happen. I'll have to trailer it into town if I do drive it on the street.

Cleaned up the 660s with the ultrasonic cleaner this weekend. Used a mixture of simple green and water, I tried the original green and the lemon one. The wife preferred the lemon over the regular simple green. It removed some of the anodize but I'm not too worried about that I'll just alodine everything when I take em back apart to put the kits and the new quick fuel metering plates in. Overall they cleaned up pretty good. The brass discolored a bit when the solution was dirty but would come clean again when I changed the fluid out. Also learned on the first throttle plate that the shafts are teflon coated as some of it came "with some help" off. Got some nice foam blocks and a couple of containers from Home Depot to store the carbs in until its time to use them as well.

Some of the prices from the machine shop.

clean and polish crankshaft and camshaft 70.00

clean, pressure test heads, valve job and assemble with not surface 320.00

hot tank clean block 60.00

one sleeve 22.45

install sleeve 40.00

line hone is 160.00

bore the hole and hone all 80.00

yeah! people who are unfamiliar with what typical machine shops charge to machine an O.E.M. block ,
look at the price of a DART block and say thats absurdly over priced,
but its not at all uncommon to get the machine work cost to get an O.E.M. block machined correctly,
exceed that total price and then your dealing with a much thinner casting, made from a weaker alloy ,iron, with far less strength,
that costs more in the long run.
I know most of us have made that mistake,
I know I spent well over $1200 on machine work,
and more on splayed main caps ARP hardware ETC.
on a 383 SBC and I could have purchased a DART SHP block,
that was better for less, by the time I was done.
you can build a 450hp sbc with a O.E.M . block, but , in my opinion,
once you start looking to exceed about 500 hp your much better off in the long run,
selecting a DART block as the more rigid and thicker block is a much better value.

the 4 bolt main cap O.E.M. BBC block , is significantly stronger and Id have zero issues building a 600-650 hp BBC,
with a good O.E.M. BBC block ,
but ID still go with that DART block on a BBC engine if I wanted too exceed 650 hp.


http://garage.grumpysperformance.com/index.php?threads/some-sources-for-engine-blocks.439/

http://dartheads.com/dart-product/iron-eagle-sbc/

https://www.summitracing.com/search/product-line/dart-shp-special-high-performance-small-block-chevy-cast-iron-bare-blocks?SortBy=Default&SortOrder=Ascending&tw=dart shp&sw=Dart SHP Special High Performance Small Block Chevy Cast Iron Bare Blocks

I disagree here now I would say money would be better spend on LS then a Dart block LS will give you BBC performance at a weight of SBC only time I would consider staying with the older Tech is if you already own most the parts. Dollar for Dollar better value. Stock LS heads flow close to AFR numbers and the tech is really starting to develop for these engines. So unless you are reusing a bunch of parts or trying to be period correct such as this engine waste of money.

BBC can make some serious numbers but still feel you are at a weight disadvantage but there are the crazy CID BBC engines that dominate drag racing with power adders. But fastest stock bottom end LS is running in 8s not that is hard to ignore.

good points, without a doubt, but your still talking about spending a great deal of cash on any car thats able to run in the 9 second or faster range , even without the engine costs included.
while I have a good deal of respect for the LS series of engines , and given the fact many salvage yards will sell you an basic LS engine from a wrecked car,(in various displacements, ) for between $400-$2500 thats certainly an option.
I think were still contemplating, and discussing, the first gen SBC build in this thread.
while Ive built several dozen 383-406 SBC, engines and quite a few more times that many 396-540 BBC engines , the fact is that the choice of engine family almost always comes down to the car owners, budget.
yes the parts you currently have and the skills , you have the tools your familiar with, and experience you have, with past engines does play a part, in that engine family selection process.
the cars potential power to weight ratio and the car owners budget being major factors.
It would seem to me that were not discussing the building of a race cars engine at this point,
nor are we looking to pitch the already accumulated first gen engine components in a dumpster or sell them off,
and starting over with a BBC or an LS based engine at this point. in any case.
you can certainly use the majority of the existing components PROVIDED the pats are inspected and check out to be in good usable condition after a detailed inspection,
(you certainly don,t want to assemble parts that are suspected of being defective in any engine ...
especially one you intend to rev the crap out of and run on the ragged edge of valve train stability.)

Well the build is still moving forward. Hope to get the heads back this week. Just got a UPS shipment with a bunch of carb parts and a few arp items for the block. Time to start applying alodine.

Finished assembling the second carb tonight. Just have to go back through and snug everything up. The new quick fuel metering plates are pretty nice just need to pick up a few jets for those. Also picked up new AED bolts with the 5/16 hex for the bowls to replace the old slotted screws. Ended up with a million left over carb parts but its good to have spares.

Got the heads back today as well. They look a lot better cleaned up. I actually had them shave a couple thou off the face to help clean it up. Before they faced them you couldnt tell there was a crack where they filled in the sparkplug cooling hole.

The heads look good. What are you going to do about the alignment pins?
If they haven't been redrilled 90 degrees to the angle-milled deck surface, this might pose a problem.
Will your head bolts also cause any interference problems? Were they spot-faced under where the head of the bolts rest?
Many potential problems arise when changing angles.

I was rereading your post from the beginning. Before you start machining the block,
you might consider using this girdle (assuming it will fit your oil pan), instead of those main straps you got off of ebay.
You would benefit from the increased clamping power from the studs, at the very least.

Other than having them mill a couple thousandths off the face of the head I haven't changed anything else. The clean up didnt even get everything just enough to make a smooth surface for the sealing ring. Once I have all the parts I plan to go through a test fit to find those issues. I can always try a offset dowel if a regular one doesn't work.

Loves302Chevy said:

I was rereading your post from the beginning. Before you start machining the block,
you might consider using this girdle (assuming it will fit your oil pan), instead of those main straps you got off of ebay.
You would benefit from the increased clamping power from the studs, at the very least.

Click to expand...

I looked at girdles but decided against it for now. I'm not sure if I choose to add one later if I'll need them to align hone it again but for now I'll take my chances without it. I don't plan to run the p!$$ out of this thing every dying minute, I don't possess that kind of free time. If I'm lucky I'll be able to haul it to vegas a few times a year and maybe cruise it in town when the occasion is right.

I've got the block back now.

Preferences on bearings? I'm looking at king xp series bearings and the machinist uses clevite h series. He installed clevite cam bearings. I feel brands probably don't matter as long as its the right material for the application.

The internet is flooded with answers for these next questions but being only a few chime in on this thread its limits the amount of bs.

Preference on assembly lube? I'm worried about long term sitting.

Sealant on core/freeze plugs, cam plug or not? Brand and type if so?

All oil galley plugs are threaded. Which loctite should I use?

Also planning to install valley vents and possibly some super magnets. Which epoxy for the magnets?

Cleaning tips? What does everyone use to scrub the cylinders when washing? I don't fancy the cylinder brush I see for that purpose.