Engine and Transmission Tech

To add another data point to the chorus, Erson specced 130/300-325 for a recent hydraulic roller cam.

I'm using 300 heads and the Ferrea Buick 6000 valves, so my spring choices to get those pressures have no relevance to your search, though.





Edited 1 time(s). Last edit at 01/06/2023 12:53PM by Roverbeam.

Apparently there's not much metal to cut the pockets deeper. Dustin didn't feel comfortable with going .050" so we seem to be limited there. Next option: Offset retainers. We need to look for a beehive retainer with a .100" offset. I think the stems are long enough and if not then lash caps can make up the difference. 0.680" diameter on the retainer, 10 degree, 0.100" offset. I sent an inquiry to CC, nothing back yet. I imagine somebody does have it.

Jim

Jim, Here is another experiment for you. Crane used to sell the same retainers for both 11/32" and 3/8" valves. If I recall correctly the height would go up if using the 11/32" and down with the 3/8". Don't know if it would be enough though. Try one of your other Beehive retainers on the rover valve and see what the difference would be? What would the difference be with the 300/Oddfire V6 valves? I think you mentioned they would be 1/16" taller

Dave was talking about having a Rover cut up head maybe he can answer how thick the seat is. Another thought for another thread, maybe someone who has a 300 head and a Rover head can make a tempate to see if we can copy the Buick accessory mounting on the Rover head by drilling and tapping?

At the bottom of the page, there are 4 pics of a cutaway head.

[www.v8forum.co.uk]


Ever see a Rover V8 sawed open to show the coolant passages? :8

[youtu.be]

Based on those photos I wouldn't have any issue with going an extra .050" deep. Makes the offset retainers easier to find too.

Jim

Or deeper if needed.

Ok, I have some updates.

Reel Steel in the UK and TA performance have both confirmed that there is no valve keeper / lock (aka collets in the UK) that are the Rover v8 valve profile and have a 10 degree angle.

TA never got back to me on a group purchase, but ReelSteel did allude to them purchasing these in 100 engines worth at a time.

So, if anyone is really wanting to run the beehives (using the Rover valves), then I'd recommend a 10-degree chevy cap, and machined out to 11 degrees. I have a very retired good machinist friend who still has his own shop and would be interested in helping with this if anyone wants to be the first.

I was actually spending a lot of time myself in the last 2 days with my heads since getting them back from the shop who skimmed them and re-cut the seats for the larger DW500/DW501 1.4/1.63" valves.

I have both the standard Rover pre 1980 (single spring) machined valve caps/retainers, and the Comp 712. I measured the heights of these relative to the top of a valve, and the Rover ones are .234" and the Comp 712 are a little shorter at .225.

I then measured my current spring pocket heights to the top of the valve, and have 1.802" pretty much across the board, no more than 3 thou variation anywhere! This is nice work from the shop that did the seats....

So, 1.8 minus 0.225 = 1.575" installed spring height. Clearly that's not going to work as all the springs in our range are 1.700 installed height.
So, I had already purchased Manley 41824 spring seat cutter, and trialed it on a scrap head. Works very nicely.

I have already purchase Comp 980 springs and these look to be a good general fit for the application.

How deep can we go on the pockets? Well I've cut up heads previously, and .332" is the min material thickness across any of the heads from the factory spring pocket to the water jacket. This is on the exhaust; the inlet is definitely thicker. You'll note these are a mix of the earlier heads and the later 10-bolt. The easiest way to tell is in the height of the "yump" of the bottom of the port; the 10 bolts are a lot lower than the 14 bolt heads; while this gives more initial flow, it becomes less of an advantage as you start seeking higher flow figures. I suspect this change was to put more tumble than swirl into the mix, presumably for emissions.

As I'm using the Crower 50233 that has 0.488 inlet and .501 exhaust lift, and the comp 980 springs are rated to .490 max lift, I'm actually going to run an installed height of 1.700 for the inlet, and relax it to 1.72 for the exhaust. Hence the inlet will meet the comp figures of 243lb at 0.49" and 92lb seat pressure, but the exahust will be 243lb at 0.51" and 85.8lb seat pressure. I don't think the loss of a little seat pressure will be an issue, especially as the valve is lighter than the inlet.

My seat pressures are a lot lower than others quoted here, but I just don't think I need that much pressure for the waisted stem valves at a 6200RPM redline. If i was going for 7000rpm, sure - but that's not what I'm planning for.

So, I will need to machine the inlet spring pockets to increase the depth by 0.125" and the exhaust by 0.145". This should still leave just under 3/16" material above the water jacket. Its not as much as I'd like, but that thinnest part of the casting is only around 90 degrees and it gets a lot thicker in the other 270 degrees.

Really, the best solution here is to use valves that are anything from 0.10 to 0.20" longer than the Rover valves (and it gets you into common valve locks/keepers/collets. I now fully understand why longer valves are often listed. Of course longer valves also means spacing out rocker gear, and then longer pushrods, so it all suddenly gets very pricey!!!!









Edited 4 time(s). Last edit at 01/09/2023 12:59PM by turbodave.

10 bolt head exhaust section.

Dave, Great work! Did you see the Dodge Viper V10 springs I mentioned above. They are for 1.75 installed height. These are also 1.7 height:

[www.summitracing.com]



Edited 2 time(s). Last edit at 01/09/2023 12:07PM by mgb260.

Those and a few other springs would be highly suitable…
But the pressures still seem a little on the high side unless you are going to be turning some big RPMs or using heavier valves???

I’m just flat running out of time right now unfortunately, otherwise I would be purchasing a 11° Carbide mill and Setting up to machine some retainers to 11 degrees.

Maybe on my next set of heads!



Edited 1 time(s). Last edit at 01/09/2023 01:02PM by turbodave.

Well, here is a potential issue...

I drew it up in CAD to better visualise it (click on the image below and it'll open in a new window).
While Beehives are great, there is only so much that can be done using the stock rover valve stem dia and the matching 11 degree locks / keepers / collets. These 11 degree jobbies sure take up a lot of room :-(

Two retainers shown, the left is the comp 712 (incorrectly listed as 980), the right is the pre 1980 single-spring non-sintered Rover item.

The beehive spring shown is the Comp 26981 with the .650 ID / .825 OD at the top of the spring, and the 1.24" OD at the botttom.

I have positioned the spring to line up with the standard spring surface.

As can be seen, lots of interference. While we could move the spring lower, this would lose installed height, and no way to get this much back

Maybe we should be looking instead at the next dia larger for the springs (1.375 ish? to get a larger ID at the top?







Edited 2 time(s). Last edit at 01/21/2023 10:30PM by turbodave.

Dave, Could you do an image of these retainers if reamed to 11 degrees?

[www.summitracing.com]

Dave, Is this the reamer we would need?

[conicalendmills.com]

Hey Jim,
It is indeed a 11-degree (22 deg included) but you need one with a major dia of at least .590" dia (and a minor dia of .400), so none of those will suffice; it'd be a custom piece.

There isn't enough info on the comp site to make a drawing unfortunately.

I can purchase a set on amazon and measure them up to see how they would work (and return if its a no-go), but if you assume that you would use a reamer and set it up to just clean up at the bottom of the existing 10 degree, you are radially increasing the diameter by approx 8 thou at the height that the top of the spring would be sitting (or 16 thou on diameter)!

I think though, there still isn't enough installed height - you're still going to be digging material out of the seat pocket in the head.
I have seen offset retainers in the past; not sure if they were for 10 degree though; obviously the further up the top of the spring, the wider the keeper/lock/collet so you start losing diameter…



Edited 2 time(s). Last edit at 01/12/2023 07:31PM by turbodave.

I just confirmed with Tim that the 10 degree keepers that TA sells have in fact the Chevy type groove. Dave was right, no help there.

Still no luck I suppose on the tapered carbide reamer? Might be easier to find in the reamer category as opposed to the end mill category.

Creating a carbide tapered reamer is not a minor undertaking, but not impossible either. For this job I would start with about a 3/4" round stock in mild steel, cut the taper, make relief cuts to locate the carbide, and then braze pieces of carbide in position. Then back to the lathe to grind the taper with a tool post grinder, followed by grinding the relief angles. Using 3 edges would give a self-centering action although it could also contribute to chatter.

Finding the pieces of carbide is as much a challenge as anything, however here is one source:

[www.carbideanddiamondtooling.com]

They would need to be roughly about 3/32" thick, .200 wide, and 5/8" long but the above ones should work.

Jim

I ordered some of the carbide pieces, after they come in I'll see about making up the body of the tool. I have everything else here that I need to make it.

Jim

Hey Jim,

II just ordered some of the retainers and will draw them up and verify there is enough meat in them to make this happen.

Cheers



Edited 1 time(s). Last edit at 01/20/2023 07:53AM by turbodave.

OK Dave, if it looks like it'll work I'll cut your retainers if you'll send me a second set for my own use. Does that sound fair?

Jim

Anyone have cut-up pic's of the 300 alum. head ? I have such a head.
Art.