i am going to build a Datsun 280Z and had previously decided to go with the 6.0 truck version of the LS1. i wanted to eventualy turbo it with an sts kit.

while i was looking on a datsun board i found a guy building a twin turbo setup for an LT1. he was using a corvet manifold turned upsideown. it seems like a very doable project. but i have some questions in genral about the LT1 before i decide.

what is this opti-spark thing? i dont know much about the LT1. what is this and are there problems with it? can they be fixed or converted to a regular ignition system?

i hear there are not many choices when it comes to heads for this motor. what about this? what do guys use?

heard it is easier to go 12's with the LS1 but after that it is cheaper to go LT1? is this just because of the huge aftermarket support of the LS1? i want to go low 11's witht his project.

i want to have more than stock cubic inches. whathave guys been doing as far as that? i know there is the classic 383 but i was going to build the 6.0 i was thinking about to a 402. so how far do people go with the LT1.....and i dont want too big of a stroke.

and finally how have people gone about giving these things a little boost? any special setups? how to they handle it?

so pretty much just convince me to use an LT1 in my project....its cheaper....make me want it!!!!

thanks

 

LT1 parts are cheaper than LS1 parts due to the LT1 being a regular small block design. You can use pretty much any 1 peice rear main seal SBC rotating assembly. The main differences are the heads are reverse flow cooled(through the heads then the block), the waterpump is driven off the timing chain, and it uses an optispark distributor(which requires a different cam dowel pin then a regular SBC cam).

The optispark is driven by the cam. It uses a LED that shines through a spinning disc with 360 slots. A photo optic eye reads the light and uses it as a trigger for when to fire. The problem is it sits below the waterpump and above the crank pulley, and is extremely sensitive to moisture. Not a good combination. There are replacements such as the Delteq setup(their full replacement kit is almost finished), the LTCC box which uses LS1 coils but still uses the optis eye, and you can also use a standard distributor. You either have to drill a hole out on the back of the intake manifold(and remove the EGR and its a tight fit even then) or buy a different intake, and then remove the plug in the block. You'll still have to leave the opti plugged in though because the computer uses it as a cam ref sensor and wont run without it. I wouldnt be to worried about the optispark though, generally its not that huge of a problem, just a pain to get off.

As far as displacement stick with either a 355(LT1 bored .030 over) or a 383 for forced induction. You can go larger(396,409,421), but anything larger than a 396 wont be reliable, and for forced induction most stick with 383 or smaller for reliability. Since its going into a Nissan Z car, the turbo kit will have to be custom, but just so you know theres more than a couple companys that make kits for the LT1(Pro Turbo Kits being probably the best).

As far as heads, the LT1 has alot of choices. AFR, ARAO 32 valve, Edelbrock, Trickflow, and Canfield have all made reverse flow cool heads for the LT1/LT4. AFR offers several heads(190cc,195cc 210cc, 220cc, 227cc, and 215rr heads) in several flow ranges, Arao makes 32 valve heads that flow around 400cfm but are expensive(5+k) and require alot of custom work. Trickflows heads are a good forced induction head due to their larger combustion chamber which helps drop compression. Edelbrocks are an average head, but affordable. Canfield made a head a while back, but I dont know much about them. But the greatest thing about the LT1 is its a SBC and there for any SBC heads will bolt right on, but have to be converted to reverse flow cooling.

Hope that helps

 

Damn fine post there Meangreen

 

Check out mas28O over on www.hybridz.org He's a prime example that you don't need turbo/nitrous/blower to run good times in the old z cars with an lt1 or ls1.

You could just do a 355 heads/cam setup for the lt1, put down ~420rwhp, which would be enough for a 10 sec pass. Just a thought. Lloyd Elliot has heads/cam packages(stock ported heads), and for ~$1700 for his package you could get the 420rwhp with the other supporting mods. Hell then you can run a 150 shot and run a deep 10.

 

lol, it's no big deal to do it. That is, if you have the time and money.
Mine's fairly simple.
Pro Turbo Kits basic assembly with a GT45 Competition turbo (102mm)
Cold Fusion Direct Port EFI nitrous kit
396 LT1 all forged with a Callie's crank

all stuffed into a nice little 240SX. You will actually have more room in that 280Z than I do, and it should be an easier swap since there is already an LT1 conversion kit offered for that car.