Alright over the holidays I found a deal for a complete H/C/I LT1 from MAF to oil pan for $800 bucks, even came with an alt and complete wiring harness. The guy was gonna put it in a RX7 and changed his mind and went MS4 cammed Ls1.

The motor has a mild rebuild. Block was linehoned and has +1 bearings, stock crank, stock rods, and new stock piston and rings. Cyl were not bored. Heads and Intake were locally ported, work doesn't look bad at all. The cam is a GM846. Injectors are 26lbs and I think are stock Ls1s, not sure. TB was also ported locally. The motor has about 500 miles on it. The guy I bought it from got it from a local builder who's known to build strong motors but keeps it all secret.

Here's my problems:

1. The motor was sprayed a 200 shot about 6 times with less than 500 miles on it.
2. Idk which valvesprings are on it since the builder is a secret squirrel and won't tell me. He just says to trust him on it. He did recommend a new timing chain.
3. I pull timing cover off to look at timing set. The chain had so much play in it I could almost take it off and the gears were worn.
3. The new Opti that was on it is fried. The cap looks like it got a lil hot and warped the cap.

I don't know if I trust the short block to hold up. I don't have the funds to do a 355 rebuild.

My question is, should I run the rebuilt block that I have concern about or swap the top end over to the motor that's in the car now that has close 135,000 miles on it.

My gut is telling me to just buy a new chain and gaskets an do the topend swap and if I can afford it, new valvesprings. I figured I'd ask you guys for your opinions.

If I had the funds I'd have the heads/intake flow benched and springs tested.


So I ask, what would you do if you had less than $700 to spend?

 

well thats a steal for the setup i would say just transfer all the stuff over to ur motor atleast you can trust ur set up then sell the short block on here for some1 to buy (lol)

 

yeah I couldn't say no when he said all he wanted was $800. I believe he paid 1200 or 1500 for it. I'm leaning towards the topend swap and going through the other block as the funds allows.

Kinda figured there would be responses since this seems to be a very opinionated site. Oh well.

 

Id just keep the motor you have now in the car and wait until you've got the cash to go through the new motor. Personally, I wouldnt go through the trouble of putting that top end on a 135,000 mile engine. A lot of people do it but thats just me.

 

Sounds very iffy as is... I'd be very afraid of the timing chain issue at the least.. Why not put the funds toward what you have already? $750 is the budget LE ported heads.... tons of used parts like cams etc come through here, just depends on your goal, if something is wrong with your car I'd understand doing it but to me is sounds like a big chance on something being beat, if its just too good to pass up, I'd consider the breakin down parts and flippin it deal also.... The cam etc seem old school, and he won't tell u what parts are is b/c they either suck or he has no clue what they are.... talk to a pro builder like LE and he tells u every spec u wanna know.....

 

Swap the topend over and later when the funds come up you have a good block to build.

 

I wouldn't like it at all if i was buying an engine, but the guy wouldn't tell me what's in it. There is something wrong with that.

 

Do LS1 injectors actually flow more than LT1 injectors?? For some reason I thought they flowed Less?

 

What a great opportunity if you have the patients...

I'd leave the car as it is, tear the new-to-you engine down and build it exactly like you want it.

When it's where you want it, take the old plant out and install the new guy.

It's like having your cake and eating it too... You get to drive your Z and take your sweet time building up any level of engine you want from a stock rebuild to a nasty overkill stroker with crazy short block strength so you can run massive induction with never a concern for bending the internal drivetrain.

But I wouldn't even consider going through the hassle of exchanging the top-end of the old motor without rebuilding the bottom end...

 

I'm leaning towards just leaving the motor in the car alone and shoot for 12.5s. While I'm chasing that goal I'm gonna go through the newer block with a .30 rebuild with forged mahle pistons. I'm also gonna have the heads flowbenched regardless if I swap them over or not. I just gotta know what I've got to work with and, if my patience and penny pinching allows it, save up for a custom cam and new springs.
I feel this would be the smart way to go but the temptation of swapping the topend is extremely high and I hope I can keep myself from doing it. You figure I would've learne d my lesson the first time when I did the Hotcam in a 100,000 mile plus motor and it spun a bearing within 5000 miles. Even the thought of just swapping the heads and intake are tempting. I just gotta be patient and start saving.

 

I was told they were LS1 injectors but who knows. lol. I do know they have 26lbs stamped on the side of them. Maybe I should take pics so someone here might be able to identify them or other parts or if the port job was good or not.

 

Is it a 26 or 28?

 

i undestand not telling everyone about your build but if he is tring to sell it to you and not running it anymore he should diclose all info to you. sounds fishy on that part

 

I would not run ANYTHING without knowing the part number of all the parts used. There is just too big of a range of parts quality, from top of the line bulletproof race parts to aftermarket garbage that is worst then stock.

"Trusting" him could leave you with crappy cheap springs that work fine for that cam but as soon as you change cams you hit coil bind or snap a spring at 6000 rpms.

If the parts are good, and they work, why wont he just tell you what they are?!? Its not rocket science and I'm sure he is not building anything that a million builders havent done before him.

PS: LS1 injectors are indeed only 26#s on an LT1. They run a vastly different fuel pressure - 58psi compared to an LT1s 43.5.

 

I'm def changing the springs, just wanna get these heads flowed first. As far as the builder not telling me what springs they are, it has become quite annoying along with why he ran a 200 shot 6 times with less than 500 miles on it. I told him I was going to change the set up with a different cam and springs and he had the nerve to tell me what he had in there was better than any combo I could come up with. I told him I've had mine since 2000 and have been researching this stuff for years and that there are plenty of h/c packages that would blow his setup away. He just laughed and said he had to get back to business and to quit wasting his time since I didn't buy the motor from him. Guess I called him too many times and finally hit a nerve. Haha, as annoyed as I am it felt good to know I was annoying him. Think I call him again tommorrow.