the car is a 91 z28. engine has 23X,XXX miles and is showing it's age so i wanted to replace it with something reliable. so i ordered a l31-r engine, part # 12530283, it should be here tomorrow(may 5) but we will see. so far i got my SCPC vortec baseplate, and some GM reusable vortec gaskets(which i love because i hate paper intake gaskets) and some other odds and ends, like new motor mounts, fluids, plugs, wires dizzy cap, rotor, t-stat...

questions so far are:

i got my baseplate however the gasket mating surface has some gouges in it. here are some pictures, it's got a few more but these are the only ones that really bother me. they are not deep, if it was an old used manifold i would not be too conserned, but it's the fact that its a brand new one i just spent $400 on. should i send it back?



cylinder #1


right rear coolant passage



fuel injectors? what size should i run? i just plan on running it stock for a while. the car has aftermarket injectors i believe they were 24 but i'm not sure(ill look into it later) with my limited knowlege i think i could get by with just stockers but i wanted to make sure.

my overall goal for the engine is fast burn heads, mini ram, a mild cam, roller rockers. but thats going to be well over a year out, i still have to recover from all this.

 

Talk to SD about the base. Doesn't look unusable to me, but like you said, it is new.

24 lb injectors would be fine. 22 lb stock injectors would also probably be fine. 19 lb stock injectors would probably be fine except under full throttle high RPM situations.

 

Doesn't look all that serious to me.

 

thanks guys for the replys...

old engine pretty much ready to come out.



and the new engine is here



couldn't find my bolts for the engine stand so it's going to have out on the floor for now.

 

i have a question about the oil cooler i guess. the thing that runs coolant to the oil filter area. do i need to keep it. i'm quessing its some kind of oil cooler that uses engine coolant??? i was just wondering if there was any reason for the coolant going over there, the stock set up just seems a little ineffecient... i wanted to have an adapter and have a aux. oil cooler that actually has oil running through it.

 

Swap a B-body LT1 oil cooler on there then

Neither cooler will net much benefit outside of a longterm race environment

 

slowly making progress... just stuck waiting on stuff to come in the mail...

 

well the swap has been done for a few months now, i have been daily driving the car for the last 2 months. getting about 20mpg back and forth to work, the best i got was 26.3 mpg on the highway. the car has alot of low end torque and absolutely no top end. few things i added were an lt1 dipstick, and gmpp spark plug wire looms, which were designed for l98/zz4 heads but i got them to work for the vortec heads.

only problems ive had, bought a rebuilt starter from autozone that lasted about a month or so then died on me, took it back and got a replacement one, and i have been thinking about getting an lt1 style starter because they are smaller and dont make as much noise as the older style starters. another problem is, i got a ticking coming from the top end, sound like a lifter, but the old engine had the exact same tick so im thinking maybe it could be an injector, my plan was to install some bosch 3 injectors, so we'll see what that does for me.

 

No top end? Well, the stock TPI engines made peak HP at 4400 rpm, and the stock L31 made peak hp at 4600. What would you like your powerband to be? And what axle ratio are you running?

 

from my experience the newer l31 motors that i have installed actually needed the lifters adjusted after a while.

another thing to check is the cooling system. i have had one that started leaking a tiny bit of coolant near the rear. no it will not turn the oil white either. best way to tell is to remove a valve cover and look under it. if there is moisture under there then enough coolant is getting in the oil to cause it to thin some. like i said it never turned the oil white. this only happened to me once. just a thought. oh and like atiila said. your stopping it short on power.

 

i know, i wasnt expecting there to be any power on the top end before i did the swap, truck cam+tpi=all low end. i have problem with it, i just want the car to drive around for now. as for the axels im just running stock 3.27 gears

 

that reminds me; the number one cause of cracked Vortec heads is coolant leaking from the rear of the intake manifold gaskets.
When I saw 26.3 mpg, I assumed 3.08:1 gears and 26+" tires. So I'd say you're doing very well.
But you can have more cam and still keep your mpg and torque while gaining some top-end. I can spec you a couple of options if you're curious.

 

hey buddy i dont mean to harp on this. but now that i have went back and read over all this. you need to pull a valve cover. that was a brand new crate engine from gm that did that to me. in the end it needed new lifters to solve the problem.