Old and New: 5.7 Vortec to 6.0 LS Swap, ‘69 FJ40 (2 Viewers)

[Rock40]

Ugh, the price you pay for hardcore wheeling. Took the PSC ram apart today in order to internally limit the stroke. Pretty obvious that the shaft is bent , 2nd one in a year

Cooler arrived tho and I got that installed and plumbed.

It’s close. Once the ram is back together I’ll try to fire it off

 

[Rock40]

This is more or less done, almost

Limited the stroke of the PSC ram to 7” using some pieces of UHMW

It drives

I like how clean everything turned out.

Things that worked:
All the AN fittings. Zero leaks at initial startup, gotta appreciate that
The repurposed FJ40 turn signal light, works great as the low oil warning
Electronics, zero gremlins so far
Speedometer, the 4k signal generated by the ECM works with the Autometer gauge, needs to be recalibrated which is simple

Doesn’t work:
Charge light on the dash. Rewiring didn’t work, light stays on permanently even though the alternator is putting out 14.6V
Clutch adjustment. Unfortunately this is a big one. I “almost” put an adjustable pivot ball in the bellhousing then threw a stock GM one in. Well I can’t get enough stroke to get the clutch to disengage to McLeod’s spec. Instead of pulling the whole engine, I’m hoping I can separate it from the trans about 1.5” and swap the pivot balls out

 

[Rock40]

The LS seems a bit quieter compared to the 5.7, not much tho. At least it’s not making a bunch of lifter noise

The power output is respectable. 2nd/3rd gear fairly hard on the throttle and it REALLY takes off. Wraps the link suspension up significantly. 4th gear feels milder, I’m putting money on the horrible 3.7:1 gearing, huge gear split in the SM420 and 37” tires as the main culprit here

All and all, not bad. I’ll keep working the kinks out

 

[Augustiron]

Nice.

What's the new 1/4 mile time?

 

[peesalot]

Where did you tie steam vent in ?

 

[Rock40]

Nice.

What's the new 1/4 mile time?

Still slow as all get out with the SM420, it simply can’t shift fast enough

 

[Rock40]

Where did you tie steam vent in ?

Steam vent, that got tied into the water pump actually since my older BeCool radiator didn’t have the appropriate fitting and I didn’t want to weld one in,

I’m REALLY fighting with trying to get the clutch to release properly currently

 

[peesalot]

what have you got for set up ? I am using a late 1970 MC & a stock slave, gm bell house & fork, luk clutch, at rest its about a credit card off fingers, I have found the MC don't like cold, at least my museum piece that still works doesnt, it burps fluid down inside of firewall then seals up, its happened 3 times over 20+ years sitting outside. What is yours doing or not doing ?

FWIW I am with ya on the shifts, the gap between 2 & 3rd is huge, you can pull 2nd to the rev limiter and it still bogs when grabbing 3rd. But you can run third fer awhile, let it eat.

 

[Rock40]

Here’s the steam line. Found an OEM 4 way piece from a 5.3 in a junkyard, both the front and rear of the heads are tied together

Used a 4AN compression fitting on the GM tube and ran it over to the water pump outlet. Threaded the water pump 1/8” NPT and called it good. Seems to work, doesn’t leak

 

[Rock40]

what have you got for set up ? I am using a late 1970 MC & a stock slave, gm bell house & fork, luk clutch, at rest its about a credit card off fingers, I have found the MC don't like cold, at least my museum piece that still works doesnt, it burps fluid down inside of firewall then seals up, its happened 3 times over 20+ years sitting outside. What is yours doing or not doing ?

FWIW I am with ya on the shifts, the gap between 2 & 3rd is huge, you can pull 2nd to the rev limiter and it still bogs when grabbing 3rd. But you can run third fer awhile, let it eat.

For now, stock FJ40 clutch master and slave. I’ve already replaced both with Japanese made units. Old ones were working fine but I wanted to eliminate that as a potential issue

I have a stock SM420 bellhousing and stock fork.

I essentially cannot get enough “travel” out of the slave to properly release the clutch as McLeod calls for .050” clearance between the disc and flywheel when released. And that is with virtually ZERO play between the throwout bearing and clutch diaphragm fingers

I’ve already pulled the motor (again) to swap throwout bearings AND now I also have an adjustable clutch pivot ball

Throwout bearing: left to right

Original CenterForce from the 5.7, original McLeod that came with the clutch and adjustable height McLeod

I also cut up the dumb AA slave bracket AGAIN. Shortened one attachment point so the slave moved inwards towards the centerline of the crankshaft. Now the slave can push on the innermost point on the fork which should make the pedal heavier AND provide a bit more throw

 

[Rock40]

So….. even with the adjustable pivot ball and the fancy adjustable McLeod throwout bearing, I’m nowhere near the .050” McLeod is calling for. I’m probably more like .010”-.015” if I was to give the throwout bearing any free play.

It nearly impossible to get the transmission into 1st without grinding and the disc is obviously dragging on the flywheel

Should also mention that the clutch pedal is adjusted ALL the way out for maximum stroke on the master cylinder. Still can’t get there

Of note though, is the fact that the Toyota master cylinder has a 3/4” bore and the slave is right around .810” (yes I know it’s actually metric but my Mititoyo calipers aren’t metric). I believe the next step is swapping master cylinders to something with at LEAST an .810” bore or greater, probably 1” Hopefully that will be able to push a greater volume of fluid and as a result, achieve a longer stroke out of the slave cylinder

I’m open to suggestions and also somewhat stumped. The old CenterForce clutch never had any issue properly releasing. The McLeod is a full 12” clutch but I wouldn’t think that would cause an issue

 

[peesalot]

What year MC ? I have same set up and I have a bit of push left after the disc releases so I know I have enough travel. I have had to double pump it to get it to quite dragging after it sits for months, no leaks or drips. I am curious which MC and I would call Georg and ask in his experience does the McCleod take more travel than the LUK ? I know for me the stock fj40 MC & slave will release the LUK on the ls. 17 years this way no issues other than when I originally installed ls and used old clutch, mistake, almost killed me & my son when it disitegrated on a long hill climb. If you can confirm the LUK & McCleod should use sam etravel I would get a late year 1970 production MC if yours is a 69

 

[Rock40]

What year MC ? I have same set up and I have a bit of push left after the disc releases so I know I have enough travel. I have had to double pump it to get it to quite dragging after it sits for months, no leaks or drips. I am curious which MC and I would call Georg and ask in his experience does the McCleod take more travel than the LUK ? I know for me the stock fj40 MC & slave will release the LUK on the ls. 17 years this way no issues other than when I originally installed ls and used old clutch, mistake, almost killed me & my son when it disitegrated on a long hill climb. If you can confirm the LUK & McCleod should use sam etravel I would get a late year 1970 production MC if yours is a 69

Thx, this is good info. I’ve got the later version master cylinder, truck must have been a late ‘69 as it’s the common triangular 3 bolt mounting pattern.

I’m suspicious that the pressure plate fingers are likely different from the CenterForce somehow. As in they need more overall travel to release. I’ve never run a LuK clutch, only CenterForce but decided to branch out and run the McLeod

I’ve got a Wilwood master with a .0875” bore on order. At about $70, it’s an inexpensive attempt at least. I should be able to make an adapter bracket easily so it’ll mount to the factory 3 bolt pattern. Being a larger bore in relation to the slave means it should push more fluid and get additional travel out of the slave. We’ll see

 

[FuglyYota]

Thx, this is good info. I’ve got the later version master cylinder, truck must have been a late ‘69 as it’s the common triangular 3 bolt mounting pattern.

I’m suspicious that the pressure plate fingers are likely different from the CenterForce somehow. As in they need more overall travel to release. I’ve never run a LuK clutch, only CenterForce but decided to branch out and run the McLeod

I’ve got a Wilwood master with a .0875” bore on order. At about $70, it’s an inexpensive attempt at least. I should be able to make an adapter bracket easily so it’ll mount to the factory 3 bolt pattern. Being a larger bore in relation to the slave means it should push more fluid and get additional travel out of the slave. We’ll see

So I’ve got no idea if this will help or not. I have a similar setup in that I have a GM v8 (5.7 vortec) with an SM465, stock iron bellhousing, what looks like the same basic clutch fork, and a 12” clutch. I run a later model FJ40 master with a slave from a ‘81 Nissan 280zx. Why? Because I had the same problem you do when I put it all in with the stock slave.

I measured the bore of the master, went to the parts store with calipers, and found that slave. It had the mounting configuration I wanted to the GM bell, with the bore that was about the same as the master. It works. Pedal travel and effort are fine.

Fun fact: It needs to use the inner mounting on the fork, if I put it in the outer one, the slave has so much travel it pops the piston out of the bore.

Other fun fact - I make my own pushrods from all thread, carefully rounding and polishing the end in the slave as the length is beyond what the Nissan one can handle.

Final fun fact - they’re really cheep. Like $14 online or less than $20 at the store.

 

[Rock40]

So I’ve got no idea if this will help or not. I have a similar setup in that I have a GM v8 (5.7 vortec) with an SM465, stock iron bellhousing, what looks like the same basic clutch fork, and a 12” clutch. I run a later model FJ40 master with a slave from a ‘81 Nissan 280zx. Why? Because I had the same problem you do when I put it all in with the stock slave.

I measured the bore of the master, went to the parts store with calipers, and found that slave. It had the mounting configuration I wanted to the GM bell, with the bore that was about the same as the master. It works. Pedal travel and effort are fine.

Fun fact: It needs to use the inner mounting on the fork, if I put it in the outer one, the slave has so much travel it pops the piston out of the bore.

Other fun fact - I make my own pushrods from all thread, carefully rounding and polishing the end in the slave as the length is beyond what the Nissan one can handle.

Final fun fact - they’re really cheep. Like $14 online or less than $20 at the store.

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Really interesting. I’ve never seen that setup before using a Nissan slave. Looks to be mounted on the passenger side of the bellhousing? I will have to see if the SM420 bellhousing has those mounting holes, they are different from the SM465