ProComp/Speedmaster aluminum heads

[yellow rose]

I never had any intention of running them completely out of the box without a thorough cleaning and inspection by at least me if not better. At this point I'm considering a machinist straight edge and my own dial gauge...

I'm all for the straight edge, but a real bore gauge (like a Sunnen) for valve guides is pretty spendy. I've seen some of the cheaper bore gauges get down to about 1 inch or maybe a bit less, but I've not seen a bore gauge go down to .375 or .342 that wasn't criminal expensive.

If you find one, post it here. I'd buy one.

 

[j par]

I'm all for the straight edge, but a real bore gauge (like a Sunnen) for valve guides is pretty spendy. I've seen some of the cheaper bore gauges get down to about 1 inch or maybe a bit less, but I've not seen a bore gauge go down to .375 or .342 that wasn't criminal expensive.

If you find one, post it here. I'd buy one.

First of all stop giving me good advice! I'm liable to do something the opposite just because...

I won't be sweatin the valve guides to death..
My biggest concern is not blowing the motor up! Beyond that I have a great running set of heads and if these we're to trash a set of valve guides Within? Amount of time??.. I mean my whole 10 passes this year and my drive to Salem and back and my little blasts around town.. I mean how much mileage could that possibly be... it might take me two lifetimes to wear out a set of valve guides at that rate..

 

[318willrun]

I never had any intention of running them completely out of the box without a thorough cleaning and inspection by at least me if not better. At this point I'm considering a machinist straight edge and my own dial gauge...

Honestly, you could do this yourself. I wouldn't be afraid of it one bit. Mostly you'd be taking them apart and cleaning them well. I would check them over like you did your cast heads that you had apart and put back together.

 

[gzig5]

I'm all for the straight edge, but a real bore gauge (like a Sunnen) for valve guides is pretty spendy. I've seen some of the cheaper bore gauges get down to about 1 inch or maybe a bit less, but I've not seen a bore gauge go down to .375 or .342 that wasn't criminal expensive.

If you find one, post it here. I'd buy one.

Agreed. Quality bore gauges or any good measuring tool, cost real money (more than your motor for a full set) and in my opinion the Harbor Freight versions aren't worth the trouble they can cause when they are wrong. A good set of hole and snap gauges, a couple round standards, and a good micrometer or two can go a long way once you learn how to use them. They do take some technique to use and that's were practicing on a known gauge comes in. It's better than guessing. I like using granite surface plates for testing flatness but a good straight edge is good too. A good B grade 12'x18" surface plate can be had for less than $50.

 

[PRH]

Guides that are on the loose side won’t cause any real problems other than premature seat wear.
Tight guides on the other hand can be catastrophic.

If you can’t get anywhere with a sensible machine shop, then you’ll pretty much have to do it yourself.

Pull them apart, keep everything in order.
Remove any assy lube from the valves & guides.
Give them the wiggle test.
With everything clean and dry, there should def be discernible play.
But not sloppy loose.

Lap in the valves, look for a uniform shade of gray all around the valve and seat.
Don’t excessively lap the valves.
15 seconds or so is plenty.
If it takes more lapping than that, there’s a problem.

Measure the installed height of the springs, and bring them, along with a retainer to a shop with a high quality tester and have them tested(with the retainer) at the installed height you measured, and the lift of your cam(installed height minus cam lift).

Straight edge on the decks.
I like them within .003 of flat for a 4 cylinder head.

Finish needs to be quite smooth for MLS gaskets.

If it’s all good, and the spring loads are a good match for your cam...... put them back together.

 

[justinp61]

I have a set of Starrett split ball gauges that I use to measure valve guides and of course a mic.

 

[j par]

Guides that are on the loose side won’t cause any real problems other than premature seat wear.
Tight guides on the other hand can be catastrophic.

If you can’t get anywhere with a sensible machine shop, then you’ll pretty much have to do it yourself.

Pull them apart, keep everything in order.
Remove any assy lube from the valves & guides.
Give them the wiggle test.
With everything clean and dry, there should def be discernible play.
But not sloppy loose.

Lap in the valves, look for a uniform shade of gray all around the valve and seat.
Don’t excessively lap the valves.
15 seconds or so is plenty.
If it takes more lapping than that, there’s a problem.

Measure the installed height of the springs, and bring them, along with a retainer to a shop with a high quality tester and have them tested at the installed height and the lift of your cam.

Straight edge on the decks.
I like them within .003 of flat for a 4 cylinder head.

Finish needs to be quite smooth for MLS gaskets.

If it’s all good...... put them back together.

I certainly appreciate your recommendation if I was to try it at home. Now I'm feeling a little in purgatory. Well I have a few dollars to take them to the shop to have them checked out to maybe staple a receipt to the slip of paper that says to check them out to keep any warranty valid. Both of the shops that I paid good money too and have done good work for me have both recommended not touching these heads. So they are out... For my hour of shop time it doesn't even sound like someone will even clean them up for me let alone Test spring rates do any shimming or anyting. No lapping valves or anything..

 

[PRH]

As Ive said previously about these heads.......
The set of SBM assembled SM heads I had in the shop this spring had no problems with the guide clearance or seat runout.
The dual springs that they can with wouldn’t have been suitable for a solid cam imo, but they were fine for the hyd cam that was used with the heads.
2 springs tested low, and those got shimmed up to make the loads equal to the others.
The valve seals fit the guides very poorly....... and had they not been replaced, the motor would have def had an oil consumption issue.

One of my customers uses quite a few Chinese SBC heads. He buys them bare along with a parts kit, brings everything over...... i check everything over, correct any issues I find, and put them together.
In the last several years, I have had very few guide clearance or seat runout issues for these heads.

On a pump gas 406 with an off the shelf solid cam, rpm type intake....... those SBC heads make right at about 500hp.
Easy peasy.

 

[318willrun]

I certainly appreciate your recommendation if I was to try it at home. Now I'm feeling a little in purgatory. Well I have a few dollars to take them to the shop to have them checked out to maybe staple a receipt to the slip of paper that says to check them out to keep any warranty valid. Both of the shops that I paid good money too and have done good work for me have both recommended not touching these heads. So they are out... For my hour of shop time it doesn't even sound like someone will even clean them up for me let alone Test spring rates do any shimming or anyting. No lapping valves or anything..

Warranty is just for craftsmanship? Once you bolt them and use them the warranty is done? I'd disassemble and clean them, inspect "by feel" the guides, reassemble lightly lap the valves and seat (clean both with alcohol/rag) and check that the valves are sealing with alcohol and then flashlight in a dark room. This is exactly what I did to the Odessa mag heads (besides having a professional machinist cut/inspect Odessa's repair).

 

[PRH]

I find it really odd that they require a third party to look the heads over to maintain warranty.
You could bring them to some shop known for poor/shoddy work, they find several things they don’t like, and “fix”(****) them up for you.
Then you have a problem cuz the shop fucked them up....... and SM is now gonna take care of you?
Mmmmmm, I don’t think so Tim.

 

[j par]

Honestly, you could do this yourself. I wouldn't be afraid of it one bit. Mostly you'd be taking them apart and cleaning them well. I would check them over like you did your cast heads that you had apart and put back together.

Not afraid...

 

[j par]

I find it really odd that they require a third party to look the heads over to maintain warranty.
You could bring them to some shop known for poor/shoddy work, they find several things they don’t like, and “fix”(****) them up for you.
Then you have a problem cuz the shop fucked them up....... and SM is now gonna take care of you?
Mmmmmm, I don’t think so Tim.

what's your interpretation of this piece of paper especially the last sentence or two..?..

 

[318willrun]

View attachment 1715405528
what's your interpretation of this piece of paper especially the last sentence or two..?..

OK, nothing there states for you do disassemble or have a pro inspect the heads. That's just saying to make sure you have clearance when installing the heads, mainly the pushrod clearance.

 

[j par]

OK, nothing there states for you do disassemble or have a pro inspect the heads. That's just saying to make sure you have clearance when installing the heads, mainly the pushrod clearance.

This is your interpretation of all aspects?..

 

[Jadaharabi]

View attachment 1715405528
what's your interpretation of this piece of paper especially the last sentence or two..?..

It is To cover their butts. It makes you responsible for everything being right with the head.

 

[318willrun]

This is your interpretation of all aspects?..

yep. I believe these are the questions they are asking you to look at: Do the rocker sit on the valves (geometry)? Do the pushrods have clearance throughout the motion? Do the valves have clearance with the pistons? Does your cam lift give the valve springs "coil bind"? Any of these fail, that would be on you and they wouldn't stand behind it.

 

[oldkimmer]

That’s right. Ur sol if u touch them or not. I like the words: Potential warranty. Kim

 

[PRH]

All aspects?

Gonna be a little tough to verify the guides and seats have the correct amount of press fit into the castings.

 

[fishmens67]

The heads are yours once bolted on, ZERO warranty. Speedmaster did not build the motor, they are not installing the heads.
It on you ! have fun

 

[oldkimmer]

That’s why Cley and I opted for a super deal on our heads. We knew it was our baby if there was a problem. Kim

 

[j par]

The heads are yours once bolted on, ZERO warranty. Speedmaster did not build the motor, they are not installing the heads.
It on you ! have fun

False advertising.....

 

[j par]

CNC SM's are not covered...

 

[famous bob]

Not afraid...

aint skeeerd !

 

[j par]

Guides that are on the loose side won’t cause any real problems other than premature seat wear.
Tight guides on the other hand can be catastrophic.

If you can’t get anywhere with a sensible machine shop, then you’ll pretty much have to do it yourself.

Pull them apart, keep everything in order.
Remove any assy lube from the valves & guides.
Give them the wiggle test.
With everything clean and dry, there should def be discernible play.
But not sloppy loose.

Lap in the valves, look for a uniform shade of gray all around the valve and seat.
Don’t excessively lap the valves.
15 seconds or so is plenty.
If it takes more lapping than that, there’s a problem.

Measure the installed height of the springs, and bring them, along with a retainer to a shop with a high quality tester and have them tested(with the retainer) at the installed height you measured, and the lift of your cam(installed height minus cam lift).

Straight edge on the decks.
I like them within .003 of flat for a 4 cylinder head.

Finish needs to be quite smooth for MLS gaskets.

If it’s all good, and the spring loads are a good match for your cam...... put them back together.

These are the specs that are givin and (for now) assumed. My cam now and 234-244@50 on 108 with 526 lift with 1.6 rockers. Solid lifter.. thinking next cam will be 575 lift..

 

[stixx]

False advertising.....

This is not false advertising. It's the same for most any engine part you can buy. But you have to read warranty details...
they will probably come up for failures due to major manufacturing defects, but as many have said... once you have bolted them
on it's basically on you.