The LZ9 MGB is finally running

[IsaacHayes]

So is the gen3 to gen4 cam swap kit ready? What is involved for swapping it in? Any machine work? The H/X pipe might make it quieter...

[robertisaar]

The H/X pipe might make it quieter...

WILL make it quieter...

and whats this about a gen3/4 cam swap? a 3 cam in a 4 block or a 4 cam in a 3 block?

[CNCguy]

There are a few LZs being built using the cam bearing spacers. We ran a small batch of spacers several months back. With the spacers, you can use a GEN-III cam and TC setup.

[IsaacHayes]

Does the gen3 timing cover fit the gen4 and match up with all the coolant ports?
So all is needed is the cam bearing spacers and you can throw in a gen3 cam? I don't see them listed on your site. What holds the spacers from moving?

[CNCguy]

There is an outer shell that a stock GEN-III bearing fits in. Then the assembly presses in like a standard bearing. In the end they are like thick walled bearings. I haven't added them to the store yet.

The older covers will bolt to the block.... BUT... you still have the issue of the coolant return system since the LZs have U-flow cooling. I have a couple of ideas but haven't done anything with them yet. As I always say... time and money.

[ForcedFirebird]

Womans car is fine with me as I have no doubt about my manhood.

Well, the way you'll be flying by the haters, it will be hard to say what the gender of the driver is

As I always say... time and money.

Isn't that the epiphany of all us fabricators?

[robertisaar]

i've got PLENTY of time, but no money......

but the local shop MAY be picking up a GM product line soon, and predictions are that they will need 50-60 more people....

guess who's ass i'm kissing when that day rolls around?

[IsaacHayes]

Can you use the gen3 setup, with the gen4 cover, and then make a flat block off plate for where the phaser went, that would give more clearance? Will the gen3 chain/etc fit under the gen4 cover?

If you add those cam adapters to the store I bet they would sell... lots of FWD people could then start using the engine with the external trigger and 3500 UIM...

[Superdave]

that's the sound the 60v6 makes with a stiffer crank. even the gen 3 3500 sounds like that. Much smoother, they idle way different too.


Nice! Looks like it hauls ass.

[robertisaar]

so, all other things being equal: crank stiffness alone changes the tone that much? wow...

i'm going to have to a hear one in person to make any final judgements, but to me, from the vids i just saw of the MGB, i consider it a loss compared to my 3100....

SD:that video of you messing around in the snow with the team green insert: which motor was that?

[Joseph Upson]

There is an outer shell that a stock GEN-III bearing fits in. Then the assembly presses in like a standard bearing. In the end they are like thick walled bearings. I haven't added them to the store yet.

The older covers will bolt to the block.... BUT... you still have the issue of the coolant return system since the LZs have U-flow cooling. I have a couple of ideas but haven't done anything with them yet. As I always say... time and money.

I think it sounds pretty good, more like a high end european motor. Some of the sound difference is due to the length and diameter of the exhaust. An easy way to address the U-coolant flow in the 3900 for fwd cars is to turn the heads around so the coolant passages exit to the rear and connect them with a "Y" tube welded to flange plates bolted to the heads over the outlets. You'll have to add a water fill neck in there somewhere, perhaps an inline filler neck instead of welding onto the "Y". Hope you plan on having it dynoed soon.

[Superdave]

so, all other things being equal: crank stiffness alone changes the tone that much? wow...

i'm going to have to a hear one in person to make any final judgements, but to me, from the vids i just saw of the MGB, i consider it a loss compared to my 3100....

SD:that video of you messing around in the snow with the team green insert: which motor was that?

3500. you can really tell inside the car, the whole RPM range sounds alot different than a 3400. I'll have some new track videos in a week or so..

http://videos.streetfire.net/video/Inside-the-3500Z_195986.htm

that was with true duals, it's quieter with the X pipe now...

[robertisaar]

now THATS what i expected to hear from the 3900.....

i'm guessing it all comes down to exhaust components.

[Joseph Upson]

Here's mine with the 5" glass packs and 2.25" exh I believe, before they were replaced with the N1 style mufflers. I like the way it sounds with the new mufflers better, seen in the last video I posted.

http://videos.streetfire.net/video/3900-V6-Turbo-Fiero-tunning-runs_159990.htm

Note the ease at which it chirps the tires, that was with the camshaft locked in the full retard position indicating that it was producing more power between shifts in that position (higher rpm) than it is now with the camshaft fully advanced because it doesn't do that as easily anymore. As CNC suspected and I agree, the stock camshaft likely has its peak performance with the cam somewhere between the stops which suggests the best thing to do when using the stock cam is to degree it in to about 4 deg advance. I believe at the moment my cam is at more than 10 deg advance in the locked position.

[pocket-rocket]

I think it's a cool little car. Really, if you think about it, most old British cars don't have an aggressive, masculine appearance. Too bad that thing wasn't done a month earlier, Marc. You could have gotten some 1/4 mile times at the meet.