GT6+ Buick V6 resurrection.

[BlownMGB-V8]

Jim, I wouldn't.

While it looks trick, the Buick boys have had trouble with that conversion. Seems it tends to snap off the bolts fastening the plate to the head, and that was with cast iron heads. Anyway why would you want to swap out a more rigid unit for a less rigid one? My guess is that the base plate is not thick enough, this method is still unproven, and may need a base at least 5/8" thick for good results.

Rich, are you having your drill rods heat treated once they are done? Might want to think about that.

Jim

[Richard/SIA]

I do have heat-treat company available locally.
Wondering if I should make a couple of spare sets?
BOP-R V8's should be the same only a bit longer.

[mgb260]

I think the only issues with the stud conversion was the 3/8" studs, plus they were used in race cars with higher spring pressures. The 5/8" thick steel plate won't flex. The head rocker pedestals would  have to be milled flat on the Buick V6. I do agree that for all out racing at high RPM's the shaft system is more stable. Morana Racing uses a similar system for the Ford V6's. The Buick rockers are junk and the aftermarket are too expensive at twice the SBC prices.

[BlownMGB-V8]

Oh I definitely agree, it's a sad state of affairs.
I think the one that was breaking the bolts used a thinner base plate, but it's been awhile since I looked. As I recall though it might have been in the 3/8 to 1/2" range. Anyway the plate was not anchored securely enough for the load and was snapping off grade 8 hardware between the plate and the head. It wouldn't take a whole lot of movement to do that if it was repetitive as grade 8 is not real resistant to flex loading, but I wouldn't really trust something with a lower tensile rating but more flex in this application. Maybe a specialty aircraft grade fastener, but then I'd worry about the threads in the head. The basic problem is taking the load from 8ea. 3/8" studs through 5ea. 5/16" fasteners to the head. If you are clamping saddles around a shaft it is a lot more secure than just clamping a plate down to an interrupted flat surface. The flat bar being used did not have nearly as much torsional stiffness as a hardened round rocker shaft to start with, and then when you attach 8 lever arms to it and apply considerable pressure alternating all over the place it isn't hard to visualize twist progressing through the bar. The shaft by contrast is a bearing and does not experience any significant twisting, primarily only vertical and some side loading.

Where you have each stud anchored into the head it works fine, but in this case the bar itself has to resist any and all twisting. (Any side loading on the studs is translated into torsion down the bar.) How hefty does it have to be to do that? I don't know. Maybe the guys have it sorted out by now. I suggested 5/8" as the next logical step but it also depends on width, and could well be more than that. Until somebody has proven that it works I wouldn't risk destroying a set of heads to be the first.

Jim

[Richard/SIA]

KB used to make and sell the drill-rod shafts, I will see if TA Perf. has them now.
If not I will only need a few details to make my own.

As mentioned TD is just up the road from me.
I know the Buick V6 and Rover/BOP are essentially the same engine with different length heads and shafts.
So I'm sure they use the same rockers.

CNC is a nuisance to set up for just one pair of shafts so may as well do several if I do any.
I have the owner of TD's card and know that he is "In to" the sort of toys I sell.
Might be able to work a trade on a set just for myself, particularly if I will accept cosmetic "Blem" parts.

So the question for the board becomes, would there be likely interest in a "Group Buy" of TD rockers and drill rod shafts?

I would not expect to make anything on the rockers and I work cheap so the shafts would be fairly priced.
Need a likely quantity in order to negotiate a group buy from TD and a price on heat-treat.

[mgb260]

Richard, 225 V6 uses Rover style rockers and smaller diameter shafts, 231/3.8 V6 uses Buick 350 style rockers and larger diameter shafts. The stud conversion on the Rover V8 uses 3/8" allen bolts to head and 7/16" rocker studs on 5/8" x 1 1/2" bar. Looks pretty stout to me:

[Richard/SIA]

TA Performance gets $600.00 for the rockers which are made for them by TD, but I'm unsure if that includes the shafts.
Speed shop is even more and does NOT include the shafts.

I'm leaning toward simplicity but no matter what I'm going to end up with about as much into this engine and trans as originally intended for the entire car build.

Got the starter to fit once I knocked a corner off to clear the block properly.
Not sure what they expect me to use for bolts since the outside bolt does not leave room for a wrench to turn.
Looks like socket heads or modify the mount some more.

[mgb260]

Yeah, That's why I like the stud setup. SBC narrow stock style roller tip are around  $100 an full roller around $200. You can use self guided or adjustable guide plates like in the Rover thread.

[BlownMGB-V8]

Jim, that one does look heavier. Do you know of anyone who has been running them for any length of time? Anyone who sells the conversion? If someone can establish a successful track record it would mean more than just about any other claim. Minimum requirements would be something on the order of .500 lift and 120#.

Jim

[mgb260]

Jim, Lanocha Racing, Morana Racing and the Classic inline aluminum head.The Rover one in the link offered to, but he wants way too much. Dave Nelson(Hot Rod article) sells aluminum  setup.The double ended studs are available from Fastenal. If you use the studs with the hex you would need to mill off the rocker stands about .340 more. Also the top part of the stud may be too long for Polylock set screws. With stock height valve covers I would use stock Chevy style lock nuts with Electrical Pal nuts for jam nuts. Pic of Tim Lanocha's motor.

[BlownMGB-V8]

I've seen a lot of photos of that engine but never knew anyone who runs one.

I do believe it can be done, but I have also seen failures. So I still consider it a little uncertain. Which could be acceptable for racing but not so much for a street engine expected to last.

Jim

[DiDueColpi]

I'm in your corner Jim. (B)

The only reasonable excuse to convert to a stud mounted rocker is the cost of the parts.
The stud mount is inherently unstable and susceptible to harmonics and flex. Especially in the Rover application where a side load is present.  
That's why stud girdles exist. They band aid the weaknesses that the stud set up has.
A shaft mount system is far more stable. Read "more accurate valve timing". AKA more power.
The Rover setup suffers from poor material choices rather than poor design. For our purposes anyway.
In a stock environment they work well.
In a more highly stressed environment the weaknesses become evident.
A simple increase in shaft diameter and rockers to match. And the valvetrain becomes the last thing to worry about.

Fred
,

[BlownMGB-V8]

That's what I wanted to say.
The other big objection is that they are not adjustable. Well, unless you run solid lifters, you should be using custom pushrods anyway (about $100 from Smith Bros and there the same week) and will never have to adjust the valvetrain. One less thing to go wrong (Or 16 less.)

Jim

[Richard/SIA]

So I've done a first mockup of F.I. bodies.
Prefer the fuel rails on the inside as it puts the adjustment screws outside and would look cleaner.
If I angle cut the adapters I can put the intake trumpets strait up.

[mgb260]

Richard, I agree on the fuel rails inside. Look pretty good! Do you see where you can mill the bottom round? What is the outside diameter of the top.

[Richard/SIA]

My calipers say 43mm for the bottom at the widest point.
Making it round will also make it thinner at the flat portions so I think 43mm is the limit.
Top is about that too.
I need a smooth transition to 46mm at the bottom while passing through the adapter.

Need to find out what sort of injectors fit too.

Also received my feeBay purchased Weiand/Smokey Yunick 4V intakes today.
Will see if one of them fits well after cleaning them up.

[Richard/SIA]

Well one Weiand manifold has been "Gasket Matched" to the max so useless for the current engine.
The other looks OK but needs a lot of cleaning.

Now to deal with the angled carb mounting plate since my engine sits flat.
More research and fabrication.

[Richard/SIA]

Got the unmolested Weiand manifold cleaned up tonight.
Need to make a new adapter plate for it so the carb will sit flat.

Also got the front suspension towers off so that I can complete welding the reinforcements in place cleanly.
Then I can strip them in my blast cabinet before painting them.

It will be nice to actually begin putting paint on parts as it's a real sign of forward progress.

[Richard/SIA]

Plated over the area where I had cut away the front suspension towers to clear the oil pump and steering shaft with 14 ga.
With the towers off the frame gravity actually worked for me instead of against me.
So my welds are much better.
Will now be able to clean the towers up in my blast cabinet.

Cannot paint yet as I have one more welding job to do.
At the top where the original engine mounts were I plan to add a plate to tie into a removable cross brace.



What they looked like before reinforcement.
Pretty sure this is stronger and it's certainly cleaner.

[Richard/SIA]

Hmm, looks like a slight deviation from the strait course.

Buying an only used once auto body Rotisserie locally for about what a Chinese version goes for before shipping.
Should make future rust repair a lot easier.
Easier is GOOD!

[Richard/SIA]

Rotisserie purchase tapped me out for a while so I've done some work with material already on hand.

Here's a pic of the passenger side first layer of frame reinforcement.



These tubes will be plug welded at  intervals to the sides and bottom of the chassis channel.
Also to each other.
Then a third tube goes on top for the outside edge.
Finally it will all be boxed over.

This will add some weight but it's down low and will probably be stronger than original.
Only way I could find to make a T5 fit.

[Richard/SIA]

So on the day after Christmas I got some sunshine to work with.
Made the most of it and finished bending my reinforcements, then drilled most of the holes for plug welding them in place.
Have to flip the frame for a few more holes but may be able to begin welding on Thursday.


No, not for lightening. :-)
Tubes will be welded at the sides and bottom, as well as to each other.
Once the bottom layer is in place I will trial fit the engine again before fitting the top tubes which I may have to notch in a couple of places.
Final step will be boxing it all over with sheet metal.


Mig welds at each inch should be pretty solid.


Most holes done for both sides.


Reinforcements loosely fitted.

[Richard/SIA]

With the bottom set of frame reinforcement tubes welded in I set the engine/trans in place to see what might be needed in mods for the top tube.

Looked like just a couple of dings on the passenger side would do it.
Came to the conclusion that the engine was canted down at the front a couple of degrees.
Raised the front of the engine one inch and all sorts of chassis clearance issues disappeared.

Decided it was time to see how the body fitment was going to work with my planned engine placement.
Found that the engine will be inside the current firewall about two inches at the right bank after leaving clearance for motion.
Will have to do some trimming for width too.
Steering column looks like it may be challenging, need to find some good pics of BOPR conversions as they should be very similar.

Have to make more measurements of the engine installed height.
I may just barely be able to remain under the bonnet without cutting it.
That is a real goal that may force me to put the engine back down that last inch.
Looking for a more compact air cleaner, maybe a remote unit and carb hat?
I've even had wild thoughts of converting the fresh air intake at the cowl into a ram-air system similar to what my El Camino has.
Wondering if there might be a shorter carb available?

[Richard/SIA]

OK, the engine is at it's final location.
1" further forward and 3/4" lower than yesterday.
Cannot go any more forward and remain behind the steering rack, cannot go any lower.

Finally lowered the body onto the chassis with the engine mocked up, in stages.
Lower, cut sheet-metal, lower some more, cut some more until it all clears.
No I do not make drawings in advance, I work it out as I go.

This is barely working out in my LHD car, RHD would not do as well.
Left engine bank barely let me retain the lower portion of the firewall that I need for the gas pedal, but I did have to cut away at the top.
Right bank sits further back and required more trimming, had to make room for the exhaust header too.
Battery will have to be relocated and I think I may be able to adapt a modern flat air filter to fit in the remains of the old battery location.
Good thing the passenger does not need as much foot room since they have no pedals to push.

Will have to reinforce the cuts as they noticeably weaken the cowl.

With just slightly thicker than stock body mounts, using a steel square from the face of the engine to the top of the scuttle, it looks like the carb will fit under the stock bonnet with NO cutting!!!!!!

From here I should be able to do my final chassis reinforcement welds, flatten a couple of spots in the tubes, and box it all in.
Have to cut and box a curve in the top of the front cross-member to clear the crank dampener.
Engine and trans mounts can be completed now too.
Firewall work will be fairly extensive but if I can bend square tube it should not be too bad.
May have to use round tube but would prefer square for ease of attaching the new trans cover.

Steering column will need a couple of joints and a support but looks like it will not be as bad as I feared.

Nothing is pretty yet but I will try to get a pic in the morning.

[Richard/SIA]

OK, pics.







Side view, top of the air cleaner should just clear since the GT-6 has a factory power bulge.