3900 FWD to RWD conversion

[CNCguy]

Since I posted much for awhile, I thought that an update on our latest work was in order. As some of you know, TCE has been working on several projects including a RWD conversion kit for the 3900s. This was initially designed for the MG swap market but would be at home in many other applications like a Stalker, rock crawler or whatever. The 3900s U-flow cooling required building a new coolant return system that uses a stock thermostat and housing.

We built four conversion kits on the first run and are planning to build three or four multiple throttle body setups for the 3900s similar to the ones were made for the Minus One. We have another welder coming and will be making long tube headers for the V6 MGs. These headers may fit some other applications. We plan to expand the header line when we get all of our tooling finished and become more efficient at building them.

I had planned to put the prototype 3900 conversion in an old school Mini Cooper but due to too many projects and time limitations, I've decided to go with a Chevette because of its light weight and being RWD.

[soultron]

In a chevette?
That will fly!

[bbeck]

The motor looks good, and the project sounds fun. What computer are you using to run this system?

[CNCguy]

It should be pretty peppy. The engine will be controlled by a Megasquirt unit and bolted to a 700R4 tranny. The next step will be to swap out the rear axle.

[IsaacHayes]

Does the kit address the VVT?

[Canyonero]

Can I fit one in an Isuzu Trooper?

[CNCguy]

In an effort to keep the overall length of the engine as short as possible, the VVT has been eliminated by using a modified cam on the prototype engine. Billet cams will be made for future engines.

I am sure that it could be put in a Trooper but would require considerably more work than the 3.4 swap. Issues like oil pan, accessory mounting and exhaust would have to be addressed.

[bbeck]

are these cams going to be available for fwd engine swaps? so we'll be able to swap in a 3900 instead of the 3400 or 3500?

[CNCguy]

The cams will be available but a 3900 can be swapped in with the stock camshaft if the cover will clear in your car. It would drop right into a W-body as is by using the external crank trigger and OBD-I. If you leave the VVT unhooked, it would run in the default position.

Vehicles with mounts that are located on the timing chain cover would be a problem since the VVT actuator protrudes from the TC cover. Another issue would be for vehicle that have an engine mount that bolts to the lower front of the block since GM moved one hole and eliminated another.

[IsaacHayes]

J and L bodies I would see the cam solenoid as causing issues with fitting. And they use the timing cover as mounts (at least the later years do I know), so something would have to be fabricated for that. And they have a torq strut down below on the front... and older years a mount. Hmm. Regardless of those issues, I'd really like to see one in a L/J body, and then with a little boost!

Unhooking the VVT causes no issues with running? It would function not retarded or advanced?

[CNCguy]

IIRC.... the default VVT position is at full advance. Joseph Upson has one in a Fiero and it's running with the VVT disconnected.

[bbeck]

I would like to run one in my car. I can't seem to find that great of a deal on one around here. Mine would be in an 88 L-body. I would like to do away with the VVT and put a nice cam in it.

[Joseph Upson]

IIRC.... the default VVT position is at full advance. Joseph Upson has one in a Fiero and it's running with the VVT disconnected.

Actually it's at full retard, although it would run either way, at full advance you would have limited top end. I was told to install the reground cam straight up which turned out to be just shy of the full retarded position so the cam is slightly retarded from the 0 deg mark where the intake valve just begins to open, or the full counter clockwise position. The return spring was removed and the actuator is being held at that point by hollow aluminum tubing internally.

[CNCguy]

I had not looked at the actuator in quite a while so I dug it out for review. Perhaps I am looking at this the wrong way but it appears to me that the locked default position is about 9 degrees advanced from straight up and the actuator can go to -18 degrees (measurements are in cam degrees, were taken with a protractor and based on the assumption that the pin is 90 degrees from the timing mark). My understanding was that advance was advancing the cam position relative to the crank. Or am I wrong about the way cam timing is measured? Doesn't a sloppy chain retard the cam timing? It can be confusing since all measurements are taken at the crankshaft.

I took a couple of pics for illustration and not accurate for measurements. I know... I'm not the best photographer. For those not familiar with the actuator, the pics were taken from the back side and the arrow depicts engine rotation. I need to get some accurate CMM measurements on this thing and make up some inserts to lock the actuator at zero degrees for those who want to run a stock or reground cam without VVT.

[bbeck]

what are going prices for all of you for these engines?