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Cleveland heads - what are these ones?

7K views 19 replies 8 participants last post by  brenx 
#1 ·
Just bought some 351 heads from a mate, for my 351 rebuild. They've been reco'd and are nice and dandy, and I took some pictures of them with my "stock" 351 heads - the ones I ripped off the engine being rebuilt.

The only thing they appear to have in common is:

- they're both Cleveland heads

Other than that, they're are a few differences that I can see. First up, the new heads don't have ANY Ford casting numbers on them. They have casting numbers, but are nothing like my heads. No Ford logos at all. I guess Ford could've changed castings, but still...

But here's why I'm stumped. Head on the left (chamber1) is my stock 351 head. Original and untouched and bloody filthy. On the right, the new 351 head (chamber2). As you can see - quite a difference. Does anyone know what I've got?
 

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#2 ·
They look like 302 cleveland heads, the chambers are quench type (closed), if the port sizes are the same between both heads you've got 302c heads, probably better for a performance build up because of the increased compression ratio, although it will be too high on a 351 for unleaded, they will need to be opened up a bit to work.
 
#3 ·
As 4Vman says, they look like closed chamber heads and will give higher compression causing pinging even on 98 PULP. Even more so if they have been shaved.

I would be getting them cc'd to determine compression ratio before they got anywhere near the top of my motor.

IMO you would be better getting you open chamber heads reco'd with hardened seats so you don't have to worry about lead additive.
 
#4 ·
My first thought was that they were 302 closed heads, but they're not. At least, they look only similar to closed 302 heads that I've seen. They're somewhere in between, if you see what I mean.

Have another look at the right hand picture - the actual "lip" of the chamber isn't round, but it's not the same shape as a 302 one. Around the inside of the lip, it tapers gradually in to the centre where the valves are...

Here's another angle... and they came off a street 351 running flat-tops, so I don't think they'll be too high a compression. But I don't mind running premium unleaded. And the reason I bought these is because they cost me less than a 1/3 of what I would've spent on getting my 351 heads done up...
 

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#6 ·
Neeek said:
My first thought was that they were 302 closed heads, but they're not. At least, they look only similar to closed 302 heads that I've seen. They're somewhere in between, if you see what I mean.

Have another look at the right hand picture - the actual "lip" of the chamber isn't round, but it's not the same shape as a 302 one. Around the inside of the lip, it tapers gradually in to the centre where the valves are...

Here's another angle... and they came off a street 351 running flat-tops, so I don't think they'll be too high a compression. But I don't mind running premium unleaded. And the reason I bought these is because they cost me less than a 1/3 of what I would've spent on getting my 351 heads done up...
Thats a better piccy. They are definately 302 closed chamber heads. Look like they have 4V valves fitted.

On my 351 even running 98 with lead additive (which reduces pinging) they pinged their heads off (pardon the pun) although I suspect mine had been shaved quite a bit. I think the cam profile can affect pinging depending on overlap - others on here will know more than me about that.

The other thing to look at is the rocker gear holes. Are the same size as your old heads and have the pedastals where the rockers mount been ground down. Make sure this is still the same as yours or you will be up for new rocker gear

I would still get them measured to work out the compression ratio.
 
#7 ·
Neeek said:
Have another look at the right hand picture - the actual "lip" of the chamber isn't round, but it's not the same shape as a 302 one. Around the inside of the lip, it tapers gradually in to the centre where the valves are...
I think that machining "de-shrouds" the valves, allowing better flow in and out of the chambers. Especially if the are bigger than standard size.
 
#10 ·
Neek, you should have a casting number on the underside of the runner like brenx. I just checked my closed and open chambers and they both have numbers there.
Closed chamber has ARD1AE
Open chamber has ARD0AE
Yours will have the top number.

edit; I can see a casting number on your second picture. What does it read?
 
#11 ·
xdclevo said:
I can see a casting number on your second picture. What does it read?
Amazing how you lot can pick up on things that I completely miss, and I'm the only one to see them in person... lol

ARD1AE is the casting number on the underside. Looks like I've got me some 302 ported heads. Which is nice. Should now all I have to do is measure the cc to see if I'm going to run into trouble with pinging.

Which begs another couple of questions:

1. How do I check volume? Fill it with water and use a syringe to measure cc?
2. What's the diff between 4v and 2v valves? Are 4v bigger and therefore flow better?
 
#12 ·
Neeek said:
Amazing how you lot can pick up on things that I completely miss, and I'm the only one to see them in person... lol

ARD1AE is the casting number on the underside. Looks like I've got me some 302 ported heads. Which is nice. Should now all I have to do is measure the cc to see if I'm going to run into trouble with pinging.

Which begs another couple of questions:

1. How do I check volume? Fill it with water and use a syringe to measure cc?
2. What's the diff between 4v and 2v valves? Are 4v bigger and therefore flow better?
Yes to 1 & 2

Whether they will flow better depends on the whole porting job. Mine had been ported quite a bit out at the manifold face but not much work done down inside so 4v valves are a waste of space

When measuring volume also allow for deck height from piston @ TDC to top of block and any valve reliefs in your piston
 
#13 ·
Cool. Looks like I got quite a good deal then, on balance. Still, Gammaboy's got his CHIs now, so he won't be needing these anymore!

I'll measure them up later in the week. And as for rocker gear, I've got all the gear directly from these heads, so there won't be any dramas there.

Quite frightening - I've got everything I need apart from ancillaries, RTV and a cleaned-up block now. Looks like I'll have a fresh 351 by the end of January! Me? Excited? Nooo... ;)
 
#14 ·
There shouldn't be any need to measure the cc.

If you know the were on a street 351 with flat tops, on pump fuel, etc then they should be fine. Only thing to consider post assembly is possibly distributor curve.

4V Valves doesn't necessarily mean flow 'better', 'bigger' probably yeah, but a lot of people now believe that better power is made without the use of 4V Valves.

Also, I'd spend the measily $50 or so and have a condition report done on them. It will tell you everything you need to know about the condition of the heads. Unless you know from the previous owner.

Don't forget when calculating comp/ratio,
Head Gasket Thickness (compressed)
Valve Reliefs in Pistons
Piston to Deck Height
Valve Dish
Bored Diameter

Hope this helps
 
#15 ·
TTNOS8 said:
There shouldn't be any need to measure the cc.

If you know the were on a street 351 with flat tops, on pump fuel, etc then they should be fine. Only thing to consider post assembly is possibly distributor curve.
And possibly camshaft, but really, with the amount they looked like they've been opened up, and most likely running the pistons 30 thou down the holes, you will only have around 9.8:1 if that.
 
#16 ·
xdclevo said:
And possibly camshaft, but really, with the amount they looked like they've been opened up, and most likely running the pistons 30 thou down the holes, you will only have around 9.8:1 if that.
Well, the engine they came from was bored 30thou over. All I know about it was that it was originally a ZH Marquis 351, and then lived in an XC for a time that was street driven. My "new" block is a virgin bore, simply because I can get away with it for now (clearances are amazingly good). In another 20,000km, I'll probably have to open it up and completely overhaul the bottom end, but for now the bottom end will be completely stock - STD sizes everywhere. And I know I'll want to throw money at the bottom end in a few years, so it's all good.

So I reckon with that, perhaps it'll run to 10:1, which is still acceptable on PULP. But it's all conjecture until I actually get the chambers cc'd.

Still, you guys have (once again) helped out! ;)
 
#17 ·
I took the guesstimate of your chambers being 65cc. Let us know, as it will be interesting for other guys wanting to add a bit of volume by releiving the closed chamber heads.
You can easily, roughly and cheaply check yourself. Get a 60ml (which is cc) "horse" seringe and a piece of perspex. Wack in your sparkplug and squirt away!
 
#19 ·
brenx said:
With mine they way there are pictured and zero deck height and flat top pistons I had 10.5:1. Mine look layed back about the same as the ones pictured.
My deck height will be more than zero, so I think I'm calm now - no need to get excited about running avgas or anything! ;)

I'll measure them this coming weekend when I'm back home. Anyone care to place bets on final volume? I shall offer a small mailable prize to whoever gets closest.
 
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