Engine and Transmission Tech

What does the stock setup look like?

Jim, Those are the stock rockers with the 93-95 3800 Buick V6 rollers instead of aluminum sled with tie bars that seem to break.




Edited 2 time(s). Last edit at 07/10/2017 07:07AM by mgb260.

The tie bars break because those puny little studs are flexing?

Carl, That may be part of the issue. The 8mm bolt is pointed like a self tapping screw and has pulled out of the bridge also. One guy has redrilled and tapped for 10mm Allen bolt threaded through the bridge with lock nuts. If they would have used steel tie bars like Oldsmobile it probably wouldn't be an issue. You still need a way to guide the rockers. With the slots in the bridge you can use Ford pedestal roller or conventional 1.7 rockers also. 4.9 are 1.6 ratio. Dodge Magnum look similar and their base channels have guide plates for the pushrods. Dodge Magnum rockers pic:




Edited 2 time(s). Last edit at 07/10/2017 04:47PM by mgb260.

Another interesting thread on rockers and cams.

[www.fiero.nl]

That does need sorted out. There was an attempt to use SBC rockers on SBB heads by attaching a base plate but it resulted in stud breakage. Too much flex. I wonder if twin tie-bars would be feasible, intake and exhaust? Might be able to link the tie-bars together for more rigidity.

Jim

Adapting parts from other makes or making parts specific for this motor for performance is the answer. It was never meant for a hot rod and just a daily driver/grocery getter.

It's interesting to me the sled rocker design being used on other engines. I have a Ford Windsor block/ Cleveland head stroker motor and I insisted on using Crane high-lift sled-type rockers with two things in mind;

- The fulcrum has that squared alignment pedestal boss that prevents the rocker arm from rotating
- The sled design of the fulcrum makes the rocker center under the fulcrum and prevents side-to-side shifting.

I have heard that Cheby BB rockers would work on Cleveland heads but I had also heard that roller rockers tended to tick because of the lateral forces from the angle of the pushrod due to the splayed design of the valve angles. As the valve is opened, the centerline of the lateral forces of the pushrod crosses the centerline of the angle of the rocker, pushing it side-to-side.

My Clevor has a roller cam conversion with valve lift of .525".

Paul

Paul, Maybe the Buick roller pedestal would work in the Ford rocker?

Remote oil filter adapter from Chad's Porsche swap site:

People have asked me my thoughts on porting the 4.9 heads. I agree with David Vizard's theories on porting. 52 percent of bore for max intake valve size and 80 percent of that for max exhaust valve size. This is to prevent cylinder shrouding. That calculates to 1.886 intake valves and 1.509 exhaust valves. SBC 1.84 and 1.50 305 HO valves would be ideal. Unshrouding chamber on outside of both valves and polishing to help prevent detonation at higher compression. Removing cast iron guides and replacing with tapered bottom bronze guides with .500 Viton seals. The floor of the port should be flattened in the corners dropping to the throat and bowl. An old head cut in two for intake and exhaust would be beneficial to see how far you could go. The intake manifold ports that curve around the pushrod hole can be ground out on opposite side to maintain width or a tube pressed in and ground down on that side. If you can get 200cfm intake and 150cfm exhaust at .500 lift, similar to ported SBF or Buick/Rover should support 350HP with the Delta E303 grind cam. Remember to use longer pushrods to compensate for reduced base circle of reground cam.



Edited 1 time(s). Last edit at 07/18/2017 11:17AM by mgb260.

Recent thread from Pennock's Forum on John's Supercharged 4.9. Studs and stud girdle. ARP rod bolts. I contacted John for more info. WOW! 52,700 hits on this link!

[www.fiero.nl]



Edited 1 time(s). Last edit at 09/28/2019 09:29PM by mgb260.

May have found an answer to replace the aluminum tie bars for the rockers. This would be for the V8 not the V6 shown, plus staggered instead of straight. Ties them all together and prevents rotation.

If you are using the Delta E303 cam you have to Dremel the rocker slot longer, also tap for longer rocker bolts Like John explains in this thread:


[www.fiero.nl]



Broken tie bar pic for thread above. Dremel the connecting piece off and use bottom fixture like above. I will have a prototype laser cut for the 4.5/4.9.




Edited 2 time(s). Last edit at 09/30/2019 03:28PM by mgb260.

Jim,
I have been working on this Ford BB 1.7 rocker arm swap also. This is what I have come up. Mounts to the Cadillac rocker arm rail. Keeps the pedestal fulcrum from rotating. I can cut the orange piece out on a CNC plasma cutter.
Cheers,
John

John, Very Cool! Welcome aboard!

Thank you, Jim. Its nice to be here!

Do you think these headers would work in a MG with a Cadillac 4.5/4.9 engine?
Cheers

Maybe the long tube headers would me a better option for a MG with Cadillac 4.5/4.9 engine.
Cheers

John the shorty ones with a longer, straighter collector without flange would probably work good. Most use the RV8 style that goes through the fenderwell. The hole also lets some of the heat out of the engine compartment. Pictures of RV8 style headers:






Edited 2 time(s). Last edit at 10/02/2019 11:59AM by mgb260.