My New Combustion Containment Devices (PROMAXX) opinions &----

[hofferwood]

-------Suggestions.

These are for my '66 Satellite with a '70 383 hooked up to a '71 727. All numbers matching (to something???).
The engine was "BUILT" by the previous owner of the previous owner. All I could get from the guy I got it from was "It's got a PURPLE CAM". Witch one he has no idea.

So I wanted the Sidewinder heads (just because). I talked to Todd at Marsh Performance and he said he didn't have any, and can't get any castings for 3 or 4 months----if then.
We talked for a while and he told me these are the same castings, and they do a good job on them.
Well I bought these fully knowing they have the wrong springs. They are setup for a hyd. roller cam. I got 'em and did the measurements on the spring pockets.
Then I talked to Todd and bought the right springs, retainers and keepers 10* (yes I wanted 10*).
They are supposedly

• Valve Angle: 15°
• Valve Seal Material: Viton
• Spark Plug Type: Angled
• Retainer Material: Steel
• Maximum Spring Lift: .600" Hydraulic Roller
• Through Head Oiling System
• Standard Port Locations
• Bronze Valve Guides
• a 5-angle competition valve job, diamond-honed bronze guides, hand bowl blending

LET THE FLOGGING BEGIN!!!!!!!! LOL

 

[496 polara]

So which castings are these?

 

[gkent]

What's on the valve stems ??

 

[RemCharger]

What's on the valve stems ??

Assembly lube

 

[Bobzilla]

These are for my '66 Satellite with a '70 383 hooked up to a '71 727. All numbers matching (to something???).
The engine was "BUILT" by the previous owner of the previous owner. All I could get from the guy I got it from was "It's got a PURPLE CAM". Witch one he has no idea.

So I wanted the Sidewinder heads (just because). I talked to Todd at Marsh Performance and he said he didn't have any, and can't get any castings for 3 or 4 months----if then.
We talked for a while and he told me these are the same castings, and they do a good job on them.
Well I bought these fully knowing they have the wrong springs. They are setup for a hyd. roller cam. I got 'em and did the measurements on the spring pockets.
Then I talked to Todd and bought the right springs, retainers and keepers 10* (yes I wanted 10*).
They are supposedly

• Valve Angle: 15°
• Valve Seal Material: Viton
• Spark Plug Type: Angled
• Retainer Material: Steel
• Maximum Spring Lift: .600" Hydraulic Roller
• Through Head Oiling System
• Standard Port Locations
• Bronze Valve Guides
• a 5-angle competition valve job, diamond-honed bronze guides, hand bowl blending

LET THE FLOGGING BEGIN!!!!!!!! LOL

View attachment 1822781View attachment 1822782View attachment 1822783View attachment 1822784View attachment 1822785View attachment 1822786View attachment 1822787View attachment 1822788View attachment 1822789View attachment 1822790

Check intake valve to cylinder bore clearance before slapping these on. If that 383 is .030" over or bigger they will likely clear but I think I remember it being close on a standard 4.25" bore diameter with those larger intake valves.

 

[hofferwood]

So which castings are these?

 

[hofferwood]

Check intake valve to cylinder bore clearance before slapping these on. If that 383 is .030" over or bigger they will likely clear but I think I remember it being close on a standard 4.25" bore diameter with those larger intake valves.

Yep, you're right I kinda forgot about cyl. wall clearance. The next warm day we get, I'll pull a plug or two and stuff my borescope down there and see if I can tell anything.
I may pull the intake and the valley tray the same day to check the cam lift at the lifters, to try and narrow down as to what "PURPLE" stick is in there.

These are the rockers I hope to use------3/8" pushrods are in it now too.

 

[PRHeads]

Rocker is contacting the stand below the shaft?

 

[PRHeads]

The as cast port openings on those heads aren’t a great match to the valley pan gasket.

 

[PRHeads]

Be sure to check the intake pushrod clearance.
3/8” don’t always fit without some relieving.

 

[hofferwood]

Rocker is contacting the stand below the shaft?

View attachment 1824027

Yes it is, that's why I took that pic+to show the old ISKY (I think) marking.
Would these be good replacement @PRHeads ?

PRW Power 9544005 PRW Shaft-Mount Rocker Arm Hold-Down Kits | Summit Racing

 

[hofferwood]

The as cast port openings on those heads aren’t a great match to the valley pan gasket.

Yes sir, I threw the paper one up there to get a look (I'll snug up the steel one to trace like you did).


These are the springs we decided on. With an installed height of 1.880, that gives us 129# on the seat (according to Compcams chart).

 

[hofferwood]

Be sure to check the intake pushrod clearance.
3/8” don’t always fit without some relieving.

Will do, If the valves don't hit the cyl. opening.------lol

 

[PRHeads]

Yes it is, that's why I took that pic+to show the old ISKY (I think) marking.
Would these be good replacement @PRHeads ?

PRW Power 9544005 PRW Shaft-Mount Rocker Arm Hold-Down Kits | Summit Racing

I’ve never used those, so I can’t help you there.

I bought a set of those Isky rockers in the 80’s, that had probably been sitting on a shelf for 15 years by then.

When I finally got around to using them several years later, I discovered they were quite a bit wider than the Crane irons I’d used in the past.

I ended up machining them down to match the width of the Cranes.
It looks like the tabs have been removed from your hold downs, like that was their solution for the width.

The other thing I remember about them was the spacer springs were super stiff compared to the Cranes.
I ended up making solid spacers out of copper tubing and got rid of the springs.
Fundamentally I have no issue using springs, but the ones that came with my Isky rockers were stiffer than I wanted on there.

 

[PRHeads]

As for valve to bore clearance………I’ve actually seen it where the 1.81 exhaust valve is the bigger offender than the 2.14 intake valve on a std bore 383.
Check both while you’re at it.

 

[hofferwood]

As for valve to bore clearance………I’ve actually seen it where the 1.81 exhaust valve is the bigger offender than the 2.14 intake valve on a std bore 383.
Check both while you’re at it.

Will do.
And just to let anyone that may be wondering, the motor is in the car, and running good. As a matter of fact it got to damn near 70 last weekend. My brother stopped by and we pulled the cover off of it and took her for about a 70 mile ride.