Engine and Transmission Tech

Jukka and all, for better springs, I use "beehives". Light/steel retainer, clears fat rockers better. Cheapest from Comp Cams
are a decent upgrade. "Pacalloy" is top-end $. Art.

I agree with Art on the Beehive springs. I used a set for a Ford recommended by Jim N., came with retainers at a good price. On extra thing to pay attention to with beehives: They should if possible be set close to coil bind at full lift I think within 1/16" or so. This is because you don't get the full benefit of their characteristic damping ability otherwise.

Jim

I've not been able to locate a smaller dia retainers for beehive springs that use the 11 degree stock Rover valve grooves / keepers - unless someone else has a solution? ReelSteel used to sell a custom keeper for the more common GM retainers to mate with the Rover Valves, but not available for several years.

As a result, I am planning on using the Comp 712-16 with Comp 980 springs

And as far as the stock 3.9/4.0/4.6 valves (1.568 / 1.356) go vs the 1.63 / 1.40 of the assumed largest size you can get on the stock seat....

The stock valve throat is around 86% of the valve dia, and the seat job is ok, but not great. If you are going to stick with the stock valves, then a performance valve job, using a .050-.060" wide seat, and a back-cut on the valve, would really help. And a blend of the valve job to the throat of course!

That said, if you go for the 1.63", and bore the throat out to a few thou over 1-7/16", it works out to 88.5% of valve area. Just the CSA of the throat is 13% larger, and of course your curtain area is improved with the larger valve. Personally, I also like the larger throat of improving the shortside just a little by giving you just a little more meat.



Edited 1 time(s). Last edit at 12/12/2022 04:57PM by turbodave.

In response to the questions on the Head CC's, this is my spreadsheet I use for Static CR.

I have measured six different "10-bolt" heads at 28.5CC.

I have Comp beehives on Merlin heads as well as Wildcat heads.

But like Dave already mentioned, there are no retainers to suit beehive spring / Rover valve locks. Unless of course Rover valves are changed to others that use GM type 7 (or 10) degree locks.

Dave, thanks. 28.5 cc is what I'll go with for my planning.

Great info Dave!

Quote:

I have measured six different "10-bolt" heads at 28.5CC.

Edited 2 time(s). Last edit at 12/13/2022 10:46AM by MGBV8.

>But like Dave already mentioned, there are no retainers to suit beehive spring / Rover valve locks. Unless of >course Rover valves are changed to others that use GM type 7 (or 10) degree locks.

Well that's a complication. Have to look into that. It's the keepers that are the issue I take it?

Jim

And the valves. The keeper retention method is different from GM.

May be a good reason to go with larger valves. ;)

Looks to me like the 4.0 heads use a 10 degree keeper. The notch is the full length of the keeper and is straight. So a plain 10 degree retainer should work. I'm working on finding the sources I used for my beehive springs and retainers.

Here's Precision Products, it seems this is where I bought the keepers:

[www.pppcenter.com]

Jim

Yeah, no one else has a keeper of the Rover V8 dimensions, so you are stuck with the only thing that'll work with the standard keepers / valves.

I still feel like it should be possible to machine the common 10 degree ones out to 11 degrees to open up all kinds of possibilities.
Just to clarify, the 11-degree is the one-side angle; the included angle is 22 degrees - per this image.

A taper-attachment on a lathe would make fast/easy work of it, as would a 11-degree tapered end mill in a bridgeport.
I'll not be going over 6200rpm for my engine, so do i really need beehive springs? I'm just not sure....

Dave, are you saying the Rover used an 11 degree keeper?

I'm not sure if the difference from 10 to 11 degrees would be enough to make a difference. Maybe someone else can answer that. My actual measurement of one of the keepers from these heads gave 10.5 degrees as far as I could tell. We could be picking at nits here.

Jim N: I'm having a little trouble finding records of my spring purchase. Do you recall where those came from? Seems to me they were an aftermarket supplier for Ford parts, maybe for FE engines.

JIm

Jim, Alex's Parts.

Been doing some checking, and exchanging some emails with Alex. Of interest, the keepers used in the Rover head are very similar to the ones used by Buick. In fact there is only .004" difference in the stem diameter inside the keeper with the groove in the Rover valves being slightly smaller, a difference that would almost seem close to manufacturing tolerances. Point being that Buick keepers would probably work fine on Rover valves. Chances seem good that this would get us to a 10 degree keeper and matching retainer for a beehive spring. Waiting to hear back from Alex on that.

Jim

With only .004" difference with Buick keepers, perhaps lap/sand needed amount off of the parting/ mirror surfaces. In other words,
so keeper halves don't "bottom-out' with each other. What is current shop cost to replace seats ? With new seats, I suspect
Stage I Buick V6 valves should work.
Art.

Buick keepers are 11 degrees too but for 3/8" stems instead of 11/32". Rover are Metric I think 8mm? Also no Buick 11 degree Beehive retainers. Maybe you could make a reamer to cut the common 7 degree Beehive retainer to 11?



Edited 1 time(s). Last edit at 12/13/2022 06:44PM by mgb260.

Rover valve stems are not metric, they are 11/32". AFAIK all Rover keepers are 11 degrees.

I just confirmed Rover valve stems are 11/32" and are the same diameter as Buick 300 valve stems. Also there is a small gap between the ends of the keepers so they will easily accommodate the .004" size difference. With the same angle they should lock up pretty much the same. Alex had nothing in the required spring diameter and installed height which is 1.240 and 1.560".

I looked at 3800 Buick valves springs but they use a 1.8" installed height.
CC has a #26123 spring with an installed height of 1.470", OD is 1.105" and spring rate of 324 and .500" max lift. Used in Ford mod and Coyote. Finding a suitable retainer might be difficult but perhaps not impossible. Still haven't looked at the specialty retainer catalogs.

PAC has #PAC-1231X which has 127#@1.550" and 287#@1.0" That one might do OK. A little on the light side and getting close to coil bind (rated 302#@.950") but that's what's wanted anyway. Maybe a bit light on the open pressure, hard to say. It's another Ford spring.

Maybe we should be looking at the Mod motor springs.

Jim



Edited 1 time(s). Last edit at 12/14/2022 09:39AM by BlownMGB-V8.

From Jukka. in 2018:

Quote:

The Rover keepers are 11 degree. Comp Cams have a set of 11 degree retainers for 1.25" spring, part number 712-16.

Edited 1 time(s). Last edit at 12/14/2022 11:32AM by MGBV8.

Buick 75-78 V6 oddfire valves are almost perfect for oversize Rover valves at 1.62" IN and 1.42 EX. Probably a lot cheaper than Rover valves. Maybe the waisted stem on the Rover valve is 8mm. Rover uses a lot shorter spring than the Buick? I used Z28 SBC springs on the 300 heads. 110 lbs closed and 300 lbs at .500 lift. 1.70 I think, installed height. The Wedge shop has performance springs for the Rover heads.



Edited 1 time(s). Last edit at 12/14/2022 10:37AM by mgb260.