Engine and Transmission Tech

Gary Walker (a.k.a. "burner1" and I have been working together on a little project, and we're ready to announce our progress.

As many of you know, Gary has a nifty CNC-operated laser and he has used it to produce header flanges for GM's little 60-degree V6. Well, I approached Gary a little while back and mentioned that I'm planning to build a second set of headers for my Buick 215 V8 one of these days. I agreed to create a flange design, and Gary made prototypes for my use. If there's sufficient interest, he'll produce and sell copies of these flanges!

So, here's what the prototype flanges look like:


As you can see, the laser leaves a really nice surface finish. These parts are quite accurately reproducible too.


Disclaimer: I haven't actually built my new headers yet. Naturally, I may ask Gary to modify the design if a problem comes along but I don't anticipate any problems.

With these flanges installed, you should be able to tighten all of the exterior cylinder head bolts. There should also be lots of clearance around the dipstick. Also, since I like tri-y headers and I really like having a slip couplings at my collectors, I figured it's likely I'll want to cut some of the webbing between cylinders apart. (That's another reason why I chose to make the webbing narrow... I built my old headers with no webbing between flanges at all.)

The main reason I'm planning to upgrade my headers is that I'm now using later-model Rover cylinder heads. Rover 4.0/4.6 heads have appreciably larger exhaust ports, so I'll increase pipe size. I designed the flanges (above) to suit original Buick 215 exhaust ports, and they'll need a little extra die-grinder work all the way around to get up to Rover 4.0/4.6 port size. Prepping the ends of your tubing to a basically rectangular shape and then matching tubes to flanges is all part of the fun, right?

My flanges will be 1/4" thick, but if you prefer thicker flanges Gary can certainly make them.

Interested?

Will they clear studs ? It would be great if anyone would consider using these, to convert sbf headers, to fit the rover. Will these flanges accept 1 5/8 primaries ? Thanks, roverman.

I took a couple more snapshots that might answer Art's questions and anticipate others.

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Art asked about clearance for studs. I don't think they'd be a problem but these photos should help you decide.



This photo shows that I made a small mistake in my first post above: these header flanges shouldn't interfere with getting a torque wrench on the middle row of (5) cylinder head bolts on a Buick 215 head - but they would block socket access to the bottom row of (4) bolts. However, late model Rover heads don't even have this bottom row of bolts. Some experts recommend that if you do have them, you shouldn't tighten them to full torque spec.

Obviously, clearance to spark plugs and wires should be good too.

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Here's a close-up of a Buick 215 head. A Rover 4.0/4.6 head looks similar except the port hole is a little larger all the way around. Art asked about using these flanges with 1 5/8" pipes. This photo should give you an idea just how whopping huge a 1 5/8" header primary would be.

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If you're determined to mate Ford headers to a Rover engine, I suggest you consider creating "step-up headers." In other words, use a smaller tube diameter at the flange to maintain exhaust velocity and then transition larger further out.

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Just for grins, I took a snapshot of spare parts from when I built my first set of headers some 21 or 22 years ago. They matched stock Buick 215 exhaust ports nearly perfectly... but with 1 1/4" sized primaries they look tiny. Anyhow, they show what I meant when I talked about matching tubes to flanges. (I made a male die and used a big hammer.)

I had thought about trying my hand at making a set of headers, how much are you thinking about for a set of flanges?

Those look pretty good. Considering it is laser cut it might be worth considering adding a curve to the connecting bar to let it go up and over the lower head bolts. It looks like there would be room to do it. Also a reverse curve at the bottom would get rid of the extra metal in the flange which is serving no purpose except to add (a minimal amount of) weight. Ounces add up. It would make it look better too in both instances.

Presumably these could also be run in stainless if one were so inclined, though if they are going to be cermachromed, why bother, right?

Jim

When I built my latest headers I used laser cut flanges. They are all individual flanges because the connecting bar interfered with spark plugs. I had the completed headers coated at finnish aircarrier workshop (good to have friends working in nice places). Apparently the same coating is used in the rearmost parts of the jet engines where it tends to get hot. As good as new even after a few years driving.

Curtis, is it a concern that you cannot get to your bolts? I would think you would not be torqing heads with headers on.

If the webbing is in the way, it could be angled to clear.

Header flanges would be about $50 a set when we make them.

Gary

IMHO, you might have an "edited" program, for larger port id's, for those who might seek more power, from their headers. If your really using 1 1/4" primaries, you'll likely make about the same power with 300 exhaust manifolds. I've built/been around, numerous, warmed over 215's- 300's, and they all liked 1 5/8 primaries ! Not for put-put use, but genuine performance. Isn't that why we build headers ? Every 215 will run stronger with 300/340 manifolds versus tiny 215 stuff. Want more bottom end ? Make longer primaries, or use tri-y's, if you must. Circumferance of a 1 5/8" is 5.102", "maybe" you can make this work ? Using sbf headers isn't quite as dumb, as it sounds. If someone finds a set that will fit their application, will save a "lot" of fab time.Onward, roverman.

They look great!

Agree with Jim about removing extra metal from the bottom.
Angled joiner would be good too, but as said, access to the spark plugs is probably more important.

Cost to get a set to Australia?

Brendan

Nearly similar and available for years in the UK:

[www.ebay.co.uk]

Similar, but have design problems,ie. dipstick tube, horizontal bracing will hit studs and port shape is incorrect. roverman.

From what I understand, these should also fit the Oldsmobile 215. Sign me up for 2 set please.I would prefer 1/4" PM me when they are ready!

You just made my day.



Edited 1 time(s). Last edit at 11/27/2012 11:03PM by Beau Dirt.

I gues the question is where would you guys ultimately like the webbing. Does tq the heads really matter? I mean the exhaust is typically off when I tq heads.

How about like the flange on top in the following image:







Edited 1 time(s). Last edit at 11/28/2012 06:18PM by burner1.

Assuming you're not using torque-to-yield (one-time-use) bolts, you re-torque after 500 miles. Right? Why would you take the headers off to do it?

The proposed change would block installation of the dip-stick on 100 percent of Buick/Rover aluminum V8s.

Good point. Where would be a good spot for the web. The web could be cut out once the headers are built.

Jim wrote:

Quote:

... Considering it is laser cut it might be worth considering adding a curve to the connecting bar to let it go up and over the lower head bolts. It looks like there would be room to do it. Also a reverse curve at the bottom would get rid of the extra metal in the flange which is serving no purpose except to add (a minimal amount of) weight. ...

This very crude illustration shows my interpretation of Jim's suggestion. My apologies to Jim if I'm reading his words wrong. I used red for metal trimmed away and grey for metal added. (Essentially three changes, each independent of the other two.)

(Obviously, the real parts would be more artfully crafted than my quick-and-dirty sketch.)

Gary, I think the webs are well positioned already and that the design is elegant as it stands. Trimming away the outer contours is so quick and easy with a side grinder, I question that it's really worth worrying about. Adding material near the spark plug holes would only make the spark plugs less serviceable.

If something needs more development, it's port size. As Art suggested, the flanges could possibly be optimized to suit specific tubing sizes or porting strategies. I haven't yet squashed 1.5" O.D. tubing pieces to see how closely I can match stock late model (4.0/4.6) ports. Once I do, I'll be able to suggest a hole shape for that application.



Edited 1 time(s). Last edit at 11/29/2012 01:59AM by Moderator.

I would love to be able to retorque my heads without removing the exhaust. I think part of my blowby problem is caused by that lower row of bolts. I can't, thought. My headers have the flanges connected similar to what y'all are proposing.

On my headers, the connecting "webbing" is nearly cut in half with a V to clear the dipstick tube. Gary's change should actually help the dipstick clearance.

Those flanges are gonna have to be bolted on a Buick 215 head to be fine tuned. It's a very fine line between the middle & lower head bolt rows. Plus, the spark plugs. Just eyeballing a 2D pic won't do. You have to be able to get a socket on the bolts & spark plugs. Gook luck!

Does anyone have a trashed head?

Totally with what Carl and Curtis said. Curtis' illustration is right on the money and dipstick clearance is a priority even over socket clearance. A bit more curve in the web as opposed to straight lines will look better.

But there is another issue even if a minor one. All heads do not have the plugs in the same place. I used a "Headers by Ed" 300 Buick flange when I built my headers. It fit the 215 heads well enough but when I went to the Olds 215 I had to cut out the webbing because the plugs were in the way. So it would be good if you could check the fit on Rover, Buick 215, Olds 215, and Buick 300 heads. And allow for head studs. Also maybe Art could test fit a template to his TA heads as they may also be different.

Because the studs are not at a 90° angle to the ports things may get interesting around the studs. You will not be able to allow as much clearance as you might like and a thin wall socket may be required. So understand that going in and just do the best you can. We don't really expect perfection, we just want it. But sometimes you get what you need.

Jim

I think my bigest problem is I don't have the engine to look at or play with.