Engine and Transmission Tech

I'm just getting ready to machine the base plates for the paired rocker sets to go on my TA heads and was wondering if it might make sense to try and adapt those to the Rover heads as well. I know Volvo rockers have been used in the past as well as the Harland Sharp rockers and have been watching the discussion about the Olds heads but don't know how the rocker shaft sizes stack up. What's the latest thinking on this?

Jim

JIm, set the rocker height at 1/2 lift for smaller wipe on the valve stem. Should be level with retainer so if you drew a line from center of roller through center of trunion. Rocker stand height determines this.



Edited 3 time(s). Last edit at 12/22/2022 06:59PM by mgb260.

Closer to edge at start of lift ? Well maybe... Load on rocker/ push rod, is quite low compared to full lift.
Art.

Art, Mid lift gives less wipe on the valve tip.

Looked at the heads again, the rocker pairs are a no-go. The TA head has twice the number of bolts to hold the base plate down and the locations are better. The bolts would fail, it's been attempted before. Guess the full shaft rockers are the only option. Haven't looked at the Rover rockers yet to see if adjusters could be substituted for the hardened tips.

Jim

Jim, Maybe you could bore the rockers to fit original shafts?

It's an interesting idea but those use a 9/16" shaft so that's going up something like 1/4"? Might be enough metal left, I'll have to look. Also have to get some suitable caged roller bearings but a good thought.

Jim

Jim, a lot of roller tip rockers just have a bronze bushing. I'd be tempted to just use the rocker itself and lube with Moly grease when installed.

That's worth considering. Looks like the bearing OD is about 3/4" which means bored/reamed to the shaft diameter would take out another .050-1/16" which would be acceptable. That means using the aluminum of the rocker as the bushing but these heads do have the pressure shaft oiling port and so do the 300 and 340 blocks so it's just a matter of making sure the head gaskets have the hole. Lots of engines used an aluminum or light alloy rocker with no bushing. It'll eventually wear out the rocker but will continue to work. So that would be one option, to modify a set of the paired rockers.

Another option would be to find individual rockers (right and left) for a larger shaft. It seems like there would be something out there that would work without too much fiddling.

Jim

Maybe big block Mopar. May be too wide and shaft is bigger at .875".

[www.ebay.com]



Edited 1 time(s). Last edit at 12/09/2022 01:45PM by mgb260.

BB Mopar sadly won’t work.
The body is far too wide at 1.560 inches.
You might get away with thinning them down but it would be sketchy for sure.
I have a good sized selection of roller tipped rockers from my quest for the perfect Rover replacement. Haven’t found anything that makes me happy yet. None of the later performance rockers that I’ve seen use a needle bearing anymore. They all use a bushing or ride on the base metal that they are made from.

Good to know Fred. I just checked the shafts on these heads and they are the .805" diameter mentioned earlier. I guess a plain bearing makes sense, from an oil pressure standpoint anyway.

These Procomp rockers I got in that paired chevy kit are .900" wide

Jim



Edited 1 time(s). Last edit at 12/09/2022 04:56PM by BlownMGB-V8.

Jim, how wide are the stock rockers?

.840"
These are .060" wider so .030" removed from the side of the pedestal should put it in the same position, might not even need to do that much. Here's one that might be worth trying with the stock rocker shafts:

[www.ebay.com]

They look similar to the kit I bought but you wouldn't be paying for the extra hardware that you wouldn't be using. A little hard to tell but it looks like they probably do have the left/right offset.

I think I might use the procomps I have on the Rover heads. The shaft bearings and clip were the cause of the reported failures and that would get rid of that. The TA heads have 1 stud per valve like chevy so this might be a better choice for them:

[www.ebay.com]

Jim

Jim, First link, one rocker is straight and one offset. In the second link you don't want 3/8" stud you want 7/16". Pushrod oiling is recommended for roller rockers anyway.

[www.ebay.com]


[www.ebay.com]

[www.ebay.com]



Edited 2 time(s). Last edit at 12/12/2022 02:18AM by mgb260.

Thirty years ago. I put a big solid lift cam in my 350. Switched to 7/16" screw in rocker studs & Harlan Sharp roller rockers. Figured with the 7/16" studs that I could forego the stud girdles. Did fine.

What exactly is the purpose of the guide plates? Can't be to center the pushrods in the holes. Is it to center the rollers over the valve tips?

Jim

Jim, Rocker alignment.

OK if I go that route then I just need to find the stud set. Shouldn't be hard. Sounds like about $200 in rockers, studs and guide plates. Then bore out the procomp rockers to fit the shafts for the Rover heads. Cool. Means I don't have to machine up the new base plates for the rocker pairs.

Jim



Edited 1 time(s). Last edit at 12/12/2022 01:10PM by BlownMGB-V8.