Speedmaster Rocker Shaft Saddles

[Earlie A]

I ran across this issue when checking some rocker geometries this morning. When bolting a rocker shaft into the saddle on a SM small block head, I noticed the shaft wiggled (quite a bit) in the saddle. I went ahead and bolted the shaft in then checked the shaft to saddle clearance with a feeler gauge. As can be seen in the pictures a 0.0015" feeler gauge can be inserted under the shaft until it almost touches the bolt. This means that shaft side to side movement is not being supported by the saddle at all and any load in the side to side direction must be controlled by the rocker shaft bolts alone. I would think this could be a tremendous side load on a 5/16 bolt anchored in aluminum threads. Not good.

I then went around checking the shaft play in any head I could find. I checked 13 heads. 5 Speedmaster, 2 ProMaxx, 2 Trick Flow and 4 mopar iron heads. 4 of the 5 SM heads had wiggle. None of the other heads had any problems.

These 5 Speedmaster heads were purchased over a period of 2 years, so this is not an isolated incident. Be curious to know if anyone else has experienced this.

 

[SSG_Karg]

Well known problem with the Speedmaster heads that was initially pointed out to me by Mike @ B3 Racing Engines. He set up a pair of heads for a friend of mine and that’s when I learned about the issue. That was 2 or 3 years ago.

 

[NC Engine Builder]

I did a post about this very issue a few years ago on here

 

[Earlie A]

Anyone heard of any failures? Given enough time or enough spring pressure and rpm this has to be a problem.

 

[NC Engine Builder]

There have been some failures, but the problem is easily corrected in a mill with a 7/8 ball nose endmill

 

[Earlie A]

Agree that it is an easy fix if you take it to a guy that is mopar machining expert like you. Wonder how many machine shops have an end mill that measures exactly 0.875? If the cutter has been sharpened to a smaller diameter the shop might try to cut the saddle with multiple passes which looks like what Speedmaster did to begin with.

This is just another expense to add to the 'real cost' of the Speedmaster head.

 

[Mtrhead]

Someone recently told me that China Machining was just as good as American....hmmmmmm

 

[gzig5]

Agree that it is an easy fix if you take it to a guy that is mopar machining expert like you. Wonder how many machine shops have an end mill that measures exactly 0.875? If the cutter has been sharpened to a smaller diameter the shop might try to cut the saddle with multiple passes which looks like what Speedmaster did to begin with.

This is just another expense to add to the 'real cost' of the Speedmaster head.

The end mill shouldn't be a problem. Tons of new ones available for about $100. Just need to find a shop with the know how to set the head up in the mill properly.

Or just mill the stands flat and make blocks that can be designed to correct the geometry without shims. W2/W5 heads had this method for years.

 

[PRH]

This is just another expense to add to the 'real cost' of the Speedmaster head.

It’s one of those, “now how much have you saved?” things.

That same problem has popped up on the BB Victor copy heads as well.

 

[Mopar Sam]

I milled my SMs for rocker blocks, but I used W2 rockers. I also put in 3/8" helicoils and used 3/8" bolts.

 

[Dart Frog]

Any head is subject to manufacturing for assembly discrepancy.. to me it seems like you spend $900 for a set of aluminum high performance Small block Mopar Head you should expect the price point to be somewhat reflective of the quality. I ran mine for going on 10 years now with approximately 30,000 miles and have got my money's worth. I had to replace one helicoil. And now I have a couple valve seals giving up. I've never run any spring pressure less than 310 on the nose and currently run over 400. It seems some people think they're going to get a high quality super small block head when they buy these heads obviously not the case. But if you're shooting for the 425 horsepower range on a weekend warrior or just a hot rod there's still a viable option.

 

[Dart Frog]

Someone recently told me that China Machining was just as good as American....hmmmmmm

I'll start with I am not a fan of offshore products. But China can and will make things to the specifications and quality demands of the buyer. So we can blame Edelbrock and speedmaster and almost every other American manufacturer that sticks their names on a Chinese product for the quality of that product. They're the ones inspecting and approving the offshore manufacturing and they are enjoying the benefits. Jmo

 

[RustyRatRod]

David Gill at Gill Welding cover this on a slant 6 head. The procedure would be the same on the V8s. Of course, this does really nothing for geometry, but it will get the shaft to fit right in the saddles.

 

[cookietruck]

David Gill at Gill Welding cover this on a slant 6 head. The procedure would be the same on the V8s. Of course, this does really nothing for geometry, but it will get the shaft to fit right in the saddles.

I didn’t watch the vid yet.

But came in here to say would a really thin shim fix this..

 

[PRH]

As I recall, didn’t Mike at B3 sort of stop doing geometry kits for the SM heads because of this issue?

 

[autoxcuda]

Could the Speedmaster rocker shafts gear they offer for this head be slightly larger diameter than stock.

Like that issue compounded itself onto this part?

 

[NC Engine Builder]

Agree that it is an easy fix if you take it to a guy that is mopar machining expert like you. Wonder how many machine shops have an end mill that measures exactly 0.875? If the cutter has been sharpened to a smaller diameter the shop might try to cut the saddle with multiple passes which looks like what Speedmaster did to begin with.

This is just another expense to add to the 'real cost' of the Speedmaster head.

Lol, it wouldn't take a expert, just a guy with a Bridgeport.

 

[Bobzilla]

Could the Speedmaster rocker shafts gear be slightly larger diameter than stock.

Like that issue compounded itself onto this part?

No. Shafts are the same.

Some of Speedmaster heads had, what looked like, two different size tools used to do the machining. Almost like they took one tool that was too large and made a pass across of the saddles, and then they used a second smaller tool and made another pass. So instead of a nice smooth curve to fit the shaft, the shaft sat "up" on the steps caused by that machining. Seams like a bunch of those were the CNC ported version.

 

[Earlie A]

No. Shafts are the same.

Some of Speedmaster heads had, what looked like, two different size tools used to do the machining. Almost like they took one tool that was too large and made a pass across of the saddles, and then they used a second smaller tool and made another pass. So instead of a nice smooth curve to fit the shaft, the shaft sat "up" on the steps caused by that machining. Seams like a bunch of those were the CNC ported version.

I have both the CNC version and the non-CNC. Both have the same issue. And you are correct. The shape of the saddle is not one continuous radius. There is a high spot in the middle of the saddle. This is the mating line of multiple passes as you describe.

 

[gzig5]

I have both the CNC version and the non-CNC. Both have the same issue. And you are correct. The shape of the saddle is not one continuous radius. There is a high spot in the middle of the saddle. This is the mating line of multiple passes as you describe.

Sounds like they are being lazy and avoiding a tool change to the correct diameter mill to cut it in one pass. Or, they simply don't understand how important it is that the shaft is fully supported and they increased the radius to allow oversize shafts to seat. None of the reasons make good sense, it's bad design/execution. Easily fixed but apparently SM doesn't care.

 

[PRH]

I don’t know how the saddles are machined, but those lines going length-wise don’t look like something you’d get from a milling operation.
Looks to me more like something that might occur in a broaching operation.

The saddles on a BB TF I have here look like they were done in a boring type of operation.

 

[Bobzilla]

I don’t know how the saddles are machined, but those lines going length-wise don’t look like something you’d get from a milling operation.
Looks to me more like something that might occur in a broaching operation.

The saddles on a BB TF I have here look like they were done in a boring type of operation.

View attachment 1716446438

Very true. Excellent observation on that.

 

[gzig5]

but those lines going length-wise don’t look like something you’d get from a milling operation

If it was done on a horizontal mill it could leave that pattern, but I don't see a lot of other operations that could use a horizontal so that might be inefficient when a milling center could do all the holes, pads, and rails in one setup.

I don't know how broaching would work on half a hole like that, but a Shaper could surely leave a linear pattern like that but doing a 7/8" radius on a shaper would be a *****, and very slow.

 

[TurboGLH]

I checked mine in 2022 with 200mi on the motor and the shaft studs had lost half their torque. I retightened and rechecked in 2024, they all had checked out at full torque.

I had mine on the Bridgeport when they were new for pushrod clearance, I'd have cleaned the saddles at the same time if knew.

But, if you didn't/can't correct it, checking after a few hundred miles seems critical

Rocker Arm help