Rob Roy

Found a low cost, low mileage 89 GT Engine. Is this a direct swap into the S4, or would the computer etc need to be changed?

Bill51sdr

I'm thinking you will need at least a chip swap in the LH to allow for the higher redline. Others more knowledgable will reply...

Hilton

The GT has a different firmware for LH and EZ-K - although someone with an EPROM burner should be able to make you the correct chips. The GT has different fuelling maps and also a higher rev limit.

I'd guess the S4 software would work, but you'd probably get less power out of it. Someone like John Speake may be able to say for sure?

Here's the firmwares for the various LH and EZ brains.

http://www.928s4.com/lh/lh_homepage.htm

Hilton.

Jim bailey - 928 International

Theoretically the GT engine is not happy in an automatic. The GTS with larger displacement they backed down on the cams for better idle quality in the automatic version. The brains will work but just not exactly the same. There would be little if any improvement in power.

Rob Roy

Thanks.

I am in the process of pulling my blown S4 motor for an R&R and cam acrosss this, and it got me to thinking - leave the current engine in while I clean up the GT and then do a swap. That way I can keep driving her longer. Sounds like it might not be worth the time and hassle

I haven't seen the motor yet, but will try to tomorrow. If I don't go for it, I'll let the board know of its whereabouts - they are asking around $1,500

Jim bailey - 928 International

That would be a STEAL the camshafts are worth that !! which is what you could do swap in YOUR cams and sell the GT cams....

Rob Roy

so aside from the cams, what are the differences? (too lazy to do a search)

John Speake

The cams in the GT engine are happier with the 775rpm idle speed that the GT LH gives. But the downside is that a GT EPROM does not have the 50rpm drop of idle speed (from the normal S4 675rpm) when you engage drive with the auto 'box.

Best to stick to the S4 ECUs, at least the LH. EZK EPROM could be changed to some advantage to suit the GT cams. Adding a little idle igntion advance to the EZK might help with the idle consistancy.

Vilhuer

Too lazy to answer your question.

Cheburator

Different pistons
Stronger heads than the ones in the '88
Port matching on the intake side
Different torque + power curves

Heck, if you don't want it - I will buy it for $1500 and have it shipped to the UK... I can always do with another spare engine for the race car...

John Veninger

We need to keep it in the US, so I'll buy it and give you a $100 finder's fee

Rob Roy

Ba$tard


j/k

DR

You will also need to swap the Temp Gauge sender and oil pressure sender from your 88 to the 89 engine. The 89-up have different connectors/sensors for those.

I sold an 89GT engine for use in an 88 (or 87) auto and the owner was VERY pleased with the results. Said it would "run circles around his older engine". His quote, not mine. I don't recall if I sent him copies of 89GT chips or if he had Autothority Chips.

Rob Roy

Bummer. Too good to be true.

Went and looked at the engine it is still in the car. I was told that the passenger compartment had experienced a fire - the whole car was toast. The motor may or may not be salvageable, but all plastic and rubber bits were melted. Internals may be ok, but I'm not going to spend that kind of money on an unknown. If anyone is interested in it, PM me. It is located in Houston.

Again, thanks to everyone for their feedback and advice.

Jim bailey - 928 International

Much depends on how the fire was exstinguished as to what might be usable BUT the cams should be OK. Also would not be that unusual for one to be set on fire after a major mechanical "OH ****" that way the insurance company buys the car for the value of a running driving car !!