LS-1/T-56 Update #2

[Phantom]

Well - I'm definitely committed now. The engine, transmission, driveshaft, radiator, oil cooler, associated hoses, exhaust, etc. are all out of the car. As it came out a lot of it basically fell apart. The entire exhaust was hanging by one nut at the header and a half-cracked through hanger at the rear. The engine mount washers broke in half as they came off. Other stuff was also about ready to go. I guess 25 years and 200,000 miles is as long as you'll want to go on an original system without tearing it down and rebuilding it. The good news is that the engine bay is solid - no rust, broken welds, etc.

The new engine and tranny get trial fitted over the next couple days and then it's off to the body shop the end of next week for detailing of the engine bay and repair of a few other small items.

QUESTION: I know the AFM and Carbon Cannister mounts can be removed to clean the engine bay up. Are ther any other little "tabs" that can safely go too? What about the mount for the fusible links and the solenoids involved in the vacuum system? This is a '77 280Z

[Guest Anonymous]

Go get em! Cool thing, I remember the excitement when I got to start to, that was cool. And yeah, when I did mine all was fine until I took the exhaust loose on the L6, out of what ever it was, three bolts, two snapped off which I was more than ok with, and one held on to impact wrench blows and wouldn't break. I finaly disconnected the exhaust where it bolts onto the stock pipe and just pulled it with part of the exhaust on..

 

Anyway, good luck with it, it'll gonna be a great conversion when its finished.

 

Regards,

 

Lone

[jeromio]

The vac solenoids etc. are for the HVAC. So, if you're keeping that, you'll wanna retain those. Although, I have a 280Z hvac system and I'm not using the solenoids.

 

Everything else can be ripped out. I even took out the entire wiring harness since I decided to just rewire it (headlights, blinkers, etc.).

[Phantom]

Jeronimo,

Since my FSM is with the car I didn't get a chance to read up on the solenoids. Do they control the position of the doors on the A/C system? Do they control anything else? How did you get around not using them?

Also, what about the fusible links? Can they just be done away with or do I need to relocate them to a better position? If so, where did you move yours?

[jeromio]

Phantmino -

 

I didn't use the fusible links - or even the solenoids. My system isn't exactly stock and doesn't exactly work all that well. I swapped a 280 HVAC unit into my 240 - hack job. I would've used the solenoids, but they don't seem to work - 15 or so years of sitting out in a salvage yard. Frozen up. They are meant to work in conjunction with the vacuum reservoir (which in my case was cracked - man I got a screwed up system). Their main purpose seems to be to boost vacuum pressure for the vac servos. I suppose the LS1 will have plenty of vac though, so, it prolly won't be an issue. With my L28, the flaps, etc. did seem to work, but very slowly. The heater valve actuation was rather weak.

 

Here's a diagram provided by FastFrog. It's much more clear than the one in the factory manual:

 

http://240z.jeromio.com/hvac.html

[Phantom]

Thanks Jeronimo. The diagram really helps. Solenoid "D" controls the pot vacuum servo that adjusts the engine idle speed on the L28 when the Ac is turned on so it defiitel can done without.

Solenoid S2, however, is used to turn the vacuum off whenever theAC system is off. It would be activated by the blower fan position switch.

An item of note is the S1. It is a little plastic check valve so vacuum can only go one way. Not sure if it really does any good but it sure can wreak havoc when it fails or is installed backwards and it shuts down the vacuum supply.

The vacuum bottle just acts as an accumulator so it doesn't affect the engine when a vacuum item is actuated. It probably can be done without on the LS-1 - unless the LS-1 has a vacuum advance as part of it's timing? If it does, I'd keep the bottle in mind.

[jeromio]

LS1 don't gots no vac advance. I think the res., S1 and the checkvalve are all meant to maximize vacuum in cases where the revs are low and someone is fiddling with all the controls over and over. I think maybe my servos are just old and crappy.

 

How are you planning to mount your A/C compressor? Are you gonna keep the Datsun towers?

 

(BTW, my "Phantmino" salutation was meant as a subtle yet apparently overly vague way of pointing out that it's jeromio, not jeronimo Seems to be a fairly common but puzzling mistake)

[Phantom]

Jeromio,

Oops - dense I am!!

For what it's worth - the bottle will increase volume but will not amplify the vacuum. What you've got - you've got. It is exactly what it's called - a reservoir - so that there is enough vacuum to actuate the system. If the system has items that are hanging up the bottle won't make a difference. Letting the engine drop to idle where the vacuum is srongest will. Beyond that you are SOL.

Haven't figured out the accessories yet but am currently planning on keeping the stock towers. I don't want to maodify any more than is necessary to do it right. May have some more on this by this time next week.

[Phantom]

Jeromio,

Another thought on vacuum. The 280ZX turbos had an electrically run vacuum pump to provide vacuum since a boosted car has a pressurized intake manifold. If all else fails you could pick one of those up at a wrecking yard and give it a try. It's one more thing to add to the car but it's not very big or heavy.