Lz9 + 4 spd manual trans in 86 GT swap

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Shaun41178(2)
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Lz9 + 4 spd manual trans in 86 GT swap

Post by Shaun41178(2) »

Doing this swap for Howard. Initial mock up shows there might be a clearance issue with the shift cables for the trans, once the adapter and tb go on. We shall see.

I'll post more updates as the swap progresses.
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by Shaun41178(2) »

Old 2.8 and cradle is out.
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FieroPhrek working on that ls4 swap for 18 years and counting now. 18 years!!!!! LOL

530 whp is greater than 312
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by Shaun41178(2) »

Engine is off the cradle I'm kind of interested in trying to see if using the factory front cover and water pump assembly will be too difficult or just swap over to the fiero stuff.

Coolant hose routing and alternator packaging are the big concerns with using factory LZ components. I'll have to mock it up and see.
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by Shaun41178(2) »

Gotta trim/grind the front mount like you do on the dohc 3.4 swaps. I also trimmed some excess webbing on the oil pan. A bit off the pan and a bit off the mount instead of it all off the mount. But that's it.
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by Shaun41178(2) »

Mounted. Easy.
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by The Dark Side of Will »

Shaun41178(2) wrote: Wed Nov 15, 2023 1:38 pm Gotta trim/grind the front mount like you do on the dohc 3.4 swaps. I also trimmed some excess webbing on the oil pan. A bit off the pan and a bit off the mount instead of it all off the mount. But that's it.

IMG_20231115_133433017.jpg

Image
Had to slot the upper bolt hole on the bracket to get it to fit?
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by Shaun41178(2) »

There is no upper bolt hole.
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by The Dark Side of Will »

Shaun41178(2) wrote: Fri Nov 17, 2023 11:52 am There is no upper bolt hole.
I must have gotten my wires crossed about which bolt hole is there and which is moved on the GenIV blocks then.

What else is the bracket attached to? One bolt ain't gonna work.
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by eHoward »

Had the same thought which is why we are trying to source an 88 bracket.
The Dark Side of Will wrote: Fri Nov 17, 2023 12:12 pm
Shaun41178(2) wrote: Fri Nov 17, 2023 11:52 am There is no upper bolt hole.
I must have gotten my wires crossed about which bolt hole is there and which is moved on the GenIV blocks then.

What else is the bracket attached to? One bolt ain't gonna work.
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by The Dark Side of Will »

I thought the 3900 had the upper water manifold at the back. I guess I was wrong about that.

Are the water manifolds two separate pieces or one large cover as with the Gen II & III engines?
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by ericjon262 »

eHoward wrote: Fri Nov 17, 2023 12:38 pm Had the same thought which is why we are trying to source an 88 bracket.
The Dark Side of Will wrote: Fri Nov 17, 2023 12:12 pm
Shaun41178(2) wrote: Fri Nov 17, 2023 11:52 am There is no upper bolt hole.
I must have gotten my wires crossed about which bolt hole is there and which is moved on the GenIV blocks then.

What else is the bracket attached to? One bolt ain't gonna work.
I would like that mount if you don't use/want it. Let me know.
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by Shaun41178(2) »

The Dark Side of Will wrote: Fri Nov 17, 2023 2:39 pm I thought the 3900 had the upper water manifold at the back. I guess I was wrong about that.

Are the water manifolds two separate pieces or one large cover as with the Gen II & III engines?
The water manifold is one piece but it's separate from the timing cover.
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by zok15 »

The Lucerne water manifold and alternator location may be the best for a low fab 3900 install. Think the hinge box just needs a trimming, and maybe an idler bolted to one of the PS pump mounting holes, but also maybe not.

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AC or and idler down there needed:

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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by ericjon262 »

This is still a work in progress, if you want to be the trial tester, let me know. This is based on an L shaped mount I picked up earlier, and an LZ4 block/oil pan that's been in my garage.

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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by Shaun41178(2) »

Interesting idea on the mount. We could do a test fit and give feedback if you want and take some pics.

I've got the front torn off and prepping for the lgd cam swap.
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by Shaun41178(2) »

Got the intakes, valve covers and pushrods out. Still need to remove timing assembly and lifters, then the lnj cam can go in
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by ericjon262 »

this point on the LZ9 block is about 13mm off the pan rail, and about 130mm from the crank centerline.

Image

however, on the LX9 (and presumably earlier blocks), the same bolt location is about 126mm from the crank centerline. both are about the same height though, at 13mm above the oil pan rail.

Image
Last edited by ericjon262 on Tue Nov 28, 2023 6:31 pm, edited 1 time in total.
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by The Dark Side of Will »

Are the block casting numbers different? It doesn't look like there's enough iron to move that bolt hole outboard 4mm
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by The Dark Side of Will »

Shaun41178(2) wrote: Mon Nov 27, 2023 9:36 pm Got the intakes, valve covers and pushrods out. Still need to remove timing assembly and lifters, then the lnj cam can go in

IMG_20231127_212702085~2.jpg
What's the point of the LNJ cam again?
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Re: Lz9 + 4 spd manual trans in 86 GT swap

Post by Shaun41178(2) »

The Dark Side of Will wrote: Tue Nov 28, 2023 10:52 am Are the block casting numbers different? It doesn't look like there's enough iron to move that bolt hole outboard 4mm

The earlier blocks have the bolt pattern the same as the 2.8. there is no need to move the bolt hole out further

Eric is saying the lz9 is out a bit further. But it's close enough with a stock mount bracket to fit. If there was a second bolt boss in the lz blocks, you would prob have to enlarge the mount bracket holes slightly

Lnj cam doesn't require the bearing spacers and deletes the vvt. The lnj could possibly be reground as well
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