I have an 87 Iroc L98 with a knock.

Opinions on

1) Rebuild...will these cars be worth anything with factory everything justifying just rebuilding what I have.

2) Crate motor...if so which? I can only find a few places have the correct rear main seal and cam?

Price to rebuild cranks, rings, gaskets, head rebuild, ....everything but tanking the block and sticking in a new cam and bearings is pretty much the same as a jasper crate.

I am fine with the hp and torque where it is and would like to keep the TPI.

Budget will not allow an LSX swap.

 

rebuild it.. get the machine work done and put it together yourself.. having an engine that you built come to life and run strong is one of the best things about working on cars.

 

If u have the space, pull out the stock shortblock and buy a new 96 vortec gm shortblock. It costs the same or cheaper than rebuilding and you'll have a better shortblock than the factory gave you. If the car becomes valuable, rebuild and reinstall the org motor. (Or sell it with the car to the new owner if that happens)

 

Without tearing the engine down, it's hard to tell how much damaged has been done. Rod knock is normally from a failed rod bearing. Failed rod bearing usually means damaged crankshaft and a con rod that needs to be replaced or resized.

By the time you spend all the money for new parts, bearings, gaskets etc plus all the required machine shop work to do a proper rebuild, a replacement engine will be much cheaper and should also come with a warranty.

 

Does the Vortec Intake from SDP or Edelbrock have to be used?

What about the cam...isn't the cam going to be more suited for a truck or towing?

 

Its only a shortblock that I'm talking about. (No heads or cam)
You will only get the block, crank/bearings, rods and pistons/rings and cam bearings. all assembled.

You will use everything else from your motor. Cam, heads, intake ect ect.

 

Looks like I need the Vortec base and can reuse everything else.

The cam in the L31 long block is a bit less than the L98 cam.

Anyone have any idea what performance numbers are like with the L31, vortec intake base, stock L31 cam, and stock TPI?

 

Ttop350

Went with a vortec long block with my stock runners, plenum, throttle body, and exhaust manifolds.

Car runs but cranks forever before starting...?

Stock chip is in it now I have a new chip but have to put it in.

Any thoughts on the hard start?

I've owned the car almost 20 yrs and it always cranked 2-3 times and started

 

Dizzy or a sensor. Oil pressure sensor - when it goes bad it can cause a hard start. It also goes bad from over cranking.

A word about jasper reman blocks... My dad got one for my GTA 20 years ago and it turned out to be an ex-taxi cab motor. With the wrong heads and internal issues which in turn gave him issues for several years til he finally got fed up with the car and almost junked it. I would stay far away from Jasper- for their price you could get a much better block for the same money or cheaper.

 

What about this. It's a stock L98 long block from autozone. http://www.autozone.com/powertrain/e...1398_332922_0/

 

Alex

Stories like your dads scared me away from Jasper.

I went with a Vortec long block with the Vortec base and my stock TPI.

The car has no drivability issues once it fires...some times it starts second time it cranks. With a fuel pressure gage on the schrader valve there is little to no pressure when the fuel pump primes before the start is engaged...once you engage the starter and the engine cranks a handful of times pressure hits 39 psi and it starts.

YA
I ended up going with a Vortec long block....give price, lead time, and the fact everything is brand new from the general.

Thanks

 

if I was a betting man which I'm not ... I would put money on the oil pressure sensor- it is on the fuel pump circuit and when it detects oil pressure it acts like a switch for the fuel pump. It is on the left hand side of the block down low towards the oil pan

 

It was a back up system for the fuel pump relay but with out it the car will have hard starts

 

I don't think it is the oil pressure switch as it is actually doing what it is designed to do. When the motor cranks for a while, the oil pressure builds and then turns on the fuel pump as described by long cranking then fire up. No pressure at the rail means the 2 second prime is not happening. This is controlled by the ecu through the fuel pump relay. Look there first. JMO!

 

Could be - it depends - do you hear the pump running (a 2 second buzzing sound) when you turn the key to on. This resets itself every 10 seconds of you don't start the car and turn the key off/
Could also be maf issue- they are known to do funny things without throwing a code.