Rebuild or JDM Swap

[RGVZX]

Ok guys I have a 91 Z TT and I dont know what route to take, should I do a rebuild or do a JDM swap!!! How much would a basic rebuild cost me? If I was to do the swap whats the best place to order it from, Ive been looking into jdmenginecorp.com!!! Thanks!!!

[marty1mc]

It depends on how bad your current motor is. If the crank is in decent shape, I would rebuild. JDM motors can't be certified for mileage or wear. It's a real crap shoot. They all will tell you between 40k and bla...bla...bla... It's BS, they have no clue.

You can get a decent rebuild kit from Z1 for around $1600. If the motor had a lot of metal damage, then I would also budget a new oil pump.

[es.biggs]

I would rebuild. A rebuild on a budget can be done for less than $2,000, including engine parts, mounts, hoses, clutch, etc. The exepensive things that would bring the cost up a lot would be oil pump, lifters, turbos, and wiring harness. If you can afford to replace those, difinitely do it.

You're really rolling the dice with JDM swaps. Some people have great experiences, but some people have had vrey bad ones - rod knock, spun bearings, bad compression, etc.

[RGVZX]

My current budget is no more than $1700!!! See what happened is I started taking apart the top part of motor such as plenum fuel rails etc... to get to remove heads but since motor is in car I got to the point where I cant remove egr to remove lower intake then remove heads!! I also noticed that the waterways on the car are bad seems they only ran it with water and no antifreeze!!! When I ran compression test cyl 1 had no compression and all the rest were at 80 psi and if im not mistaking a good motor has to be around 170psi!!! I found jdm motor with transmission on jdmenginecorp.com for $1675!!!

[vulcanrush]

jdm engines are such a crapshoot, but get a compression-test first.

[RGVZX]

Jdm online has one for the same price with a video compression test, and all cyls are over 170 psi! I would rebuild but no one here knows about Z's! Nobody wants to touch these cars! I live in mcallen tx

[vulcanrush]

texas is the place for z-knowledge, second to possibly california.
you have kyle over at ipp, and two of the best machine shops in the country, g&g and westside performance.
so many shops in texas, search tt.net for more.

as for the compression-test on video, i'm not a big fan of that, i prefer to do it in person.
if it turns out to be junk, the hassle of sending it back, even if they pay for it. and you know they'll give you a hard time about getting your money back. also, what's to say they didn't pour a spoon of oil to get the compression numbers up. not accusing them, or anything, but just looking out for your money.

if you're on a budget, it's cheaper to do it right.

[RGVZX]

I finally found somebody that knows about Z's, he came to check out my Z and told me that its a head job ima need, it could be a bad valve or simply headgaskets! $750 for all work done including parts!

[vulcanrush]

search first before you decide to get this gentleman to do it for you, go on tt.net and search around, if it's just headgaskets, that's pretty pricey.

[AchilleZ32]

I think a complete rebuild might be beyond your skillz yo. However, as for your compression numbers, I believe you're doing it wrong.

[es.biggs]

Yeah those are some funky compression results. Are you sure you did the test right? Either way, you had one cylinder that was way off from the rest - that inconsistency means there is a problem.

also, what's to say they didn't pour a spoon of oil to get the compression numbers up. not accusing them, or anything, but just looking out for your money.

^^^^ That's a very good point. I had bad compression on one of my cylinders once, was getting 60 psi - I poured a spoonful of oil inside and it went up to 170.

Do the turbos have to be removed to get the heads out of a TT?

[BigTDogg (MA)]

Do the turbos have to be removed to get the heads out of a TT?

I'm sure some crazy sonofoabitch has done it, but it's definitely not recommended to try it. You'd at least need to disconnect the water and oil lines.

Personally, I'd find a good condition used USDM motor, do a 60K/120K service on it and be done with it. For your budget, just engine, no upgrades, I think that would be the smartest money spent.

If the mechanic did their own compression test, post the numbers. Compression can be bad for many reasons; some only require a head pull (head gasket, bent valves), others require a rebuild of the bottom end (hole in piston, shot rings).

[txQ45]

If you have zero on one cylinder that's usually a bent valve.. the 80psi ones being completely across the board isn't a blown headgasket.
I work on them here in Dallas,, and do contract work for a couple of shops that won't work on them .. would rather have me come over and do the work then add $$$ for their hourly rate..