My home inspection of Speedmaster heads

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One head is 2017,,,,have to look at the other later..i bought these back in 2018 on Black Friday
I really don't know that it matters but it seems to be the latest question like there's some validity to what year they were made or how long they've been sitting on the shelf I guess..
 
Latest question seems to be what is the date code on them and are they the same?..
The set I picked up used, are several years old. Their guides were fine and the seats are still in them.
Some early SBC an SBF ones I saw had soft guides, they were also oddball sizes on the od. Had to order them from PEP. Had to be careful when removing them with the air driver or the would mushroom. All the small block Mopar ones I have seen have had .545 od guides which are an easy to get size, haven't seen any soft ones in them.
 
Guides and seats go bad sitting on the shelf?,,,,,,,lol
I think what's got people asking the question is that there was supposed to be some kind of inconsistency in quality years ago.. worried that if they had some older heads that they wouldn't be the same quality as something newer..
Just internet Boogeyman stuff...
 
The BB Victor copies I fixed a couple years ago had the oddball guides in them.
All 16 were shot.

The guides were absolutely a problem with ProComp heads for a while.
 
First data from @PRH. Out of the box CNC.

Lift—- in/ex
.100— 64/49
.200—126/95
.300—166/132
.400—206/163
.500—242/179
.600—271/187
.700—284/190
 
First data from @PRH. Out of the box CNC.

Lift—- in/ex
.100— 64/49
.200—126/95
.300—166/132
.400—206/163
.500—242/179
.600—271/187
.700—284/190
Only thing I could remember from the non-CNC'ed I thought was 250 at .500?
 
What's happening at .300-.400?

No idea. Heads are getting a decent valve job, and then we'll have a discussion about what the next move is, if anything.

I've already decided to finish my roller cam upgrade so they're getting new springs/keepers/retainers.
 
What's happening at .300-.400?
What’s happening is....... for a ported head with a 2.02 valve at those lifts........ they kinda suck.

From a flow standpoint, the valve job sucks, and the throat is too big.
There is essentially no top or bottom angle....... so there isn’t a properly shaped transition from the bowl out around the valve and past the seat, so the port can’t move any air until you get the valve way off the seat and out of the way.

For the typical street/strip guy........ running these ootb isn’t going to be the magic you were hoping for.

They have potential...... as seen by the .600+ flow numbers.
But they’re not anything special ootb.
 
Last edited:
as in??

From a flow standpoint, the valve job sucks, and the throat is too big.
There is essentially no top or bottom angle....... so there isn’t a properly shaped transition from the bowl out around the valve and past the seat, so the port can’t move any air until you get the valve way off the seat and out of the way.

For the typical street/strip guy........ running these ootb isn’t going to be the magic you were hoping for.

They have potential...... as seen by the .600+ flow numbers.
But they’re not anything special ootb.

You just answered it.
 
It's not good, but Dwayne has confidence there's a lot in the valve job, so we're going to see where that gets us and go from there.


Do you have any pictures of the shortside with a valve out looking up at the shortside like it’s a dam or waterfall
 
What’s happening is....... for a ported head with a 2.02 valve at those lifts........ they kinda suck.

From a flow standpoint, the valve job sucks, and the throat is too big.
There is essentially no top or bottom angle....... so there isn’t a properly shaped transition from the bowl out around the valve and past the seat, so the port can’t move any air until you get the valve way off the seat and out of the way.

For the typical street/strip guy........ running these ootb isn’t going to be the magic you were hoping for.

They have potential...... as seen by the .600+ flow numbers.
But they’re not anything special ootb.

That's the issue with all those heads in seen. The throat is too dam big for the valve size and valve job.

The options are use a bigger valve and keep the 45 or use the 2.02 and use a 50 degree valve job.

If I can fit the 50 degree seat on the valve face that's what I do.
 
First data from @PRH. Out of the box CNC.

Lift—- in/ex
.100— 64/49
.200—126/95
.300—166/132
.400—206/163
.500—242/179
.600—271/187
.700—284/190
Just for fun, what year were your heads?
 
First data from @PRH. Out of the box CNC.

Lift—- in/ex
.100— 64/49
.200—126/95
.300—166/132
.400—206/163
.500—242/179
.600—271/187
.700—284/190
Very disappointing #'s. A valve job and some cleanup should bring the #'s up some.
Only thing I could remember from the non-CNC'ed I thought was 250 at .500?
I guess 250 at .500 is wishful thinking with the standard SM head. Get your grinder out :D
 
Very disappointing #'s. A valve job and some cleanup should bring the #'s up some.

I guess 250 at .500 is wishful thinking with the standard SM head. Get your grinder out :D
I'm not worried about these numbers whatsoever LOL.. just interesting to look at and talk about.. I don't think I'm going to lose anything by putting these heads on except for weight...
 
That's the issue with all those heads in seen. The throat is too dam big for the valve size and valve job.

The options are use a bigger valve and keep the 45 or use the 2.02 and use a 50 degree valve job.

If I can fit the 50 degree seat on the valve face that's what I do.

Just looking at these things I'd love to try a 2.055 valve with a 50° seat. I'd also get a .050 shorter length so I could sink the valvejob a bit so as to get a wide top cut and not have geometry nightmares.
 
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