scott84

Howdy all!
The mongrel, as I call her started life as an ordinary 1990 Base GTU. At some point before I bought her she had a full s5 T2 swap engine, trans, rear end. Then she must have lost compression and one of the PO's rebuilt the engine and repainted the body did a whole mess of work to her. But the guy that I bought the car from didn't know anything about the car and that's where my troubles started. When I got the car there was a skew of electrical issues and boost leaks. Once I got those fixed the car ran great, it ran like a bat out of hell. It was fantastic but short lived because I was ignorant in the ways of turbo rotary's and fuel cut defenders. The car had an intake and turboback exhaust and a FCD. This set up flowed way to much air for the stock fuel system to handle and with the FCD allowing more than stock boost levels it lead to detonation. And that lady's and gentlemen is how I ruined rebuilt engine with around 4000 miles on it if that.... .

So I had a turbo S4 engine that I got really cheap that someone left behind in storage. The story was that this was a rebuilt engine that was ran for a while but not long. I had planned on running this motor till I get my S5 motor rebuilt... Yesterday I tore into the S4 engine for inspection, I do not planned on splitting the housings. I was not impressed when I found an apex seal spring in the oil pan. I inspected the apex seals and they all seam to have the same sort of spring rate when pushed in so I imagine it was an old one and the pan was used as a parts dish during disassembly and was not cleaned enough? idk that't just plain scary. I also found out that it is a bridge ported motor, whether it's a half or a full bridge I don't know. The S4 engine came with 2 different fly wheels, so I decided to do a little research on them. The flywheel that is on the engine is a n350 which is totally wrong, this is a s4 engine the n350 flywheel came on the NA s5 engine! The other flywheel that came with the engine is a FD flywheel which is also wrong! But who knows this s4 engine could have s5 internals and front counter weight and everything would be balanced right then? If I do put it in and it seams to be unbalanced then I'll know why... To convince my self that this engine wasn't a boat anchor I preformed a real redneck compression test. I squirted oil in the housing and stuck my compression tester in the leading plug hole and wrapped a rope around the fly wheel and yanked that sucker as hard as I could. which was only really one revolution and I saw a blip of almost 30 on my gauge. It has compression! So I did the other rotor and saw about the same! So I put the check valve back in my tester and yanked some more, on one of the rotors it went as high as 90 after a few pulls and the other was about 65. It seams as if this engine isn't a total loss yet.

Here's some pic's from yesterday.




The apex spring I found in the oil pan.


The N350 Flywheel. Notice the bolts snapped off in the puller threads...


The floating engine. I am using an engine hoist thats rated to pull up to 3500 lbs when the booms extended. I could just pick up the car with it .
I am concerened on how lose the oil drive chain is. It seams really loose for an engine that should rev to 9k, does it tighten up any when the front cover is installed? Is there a way to tighten it up?


Any ways Thanks for looking guys!

Hatchet Jack

I guess your spare engine must have had an na tranny behind it. I was wondering if it was just a turbo engine used in an na setting, being bridged and all, but then I saw that AN fitting on that front iron. You should be able to feel whether or not it's half or full bridged by feeling the ports to see if all ports have a bridge. I have no knowledge tuning with a stock ecu, but a bridged turbo on a stock ecu doesn't seem possible or safe.

I bought a 75k turbo S4 engine that sat for a while, but the surface of the center iron was bulged near the bottom on both sides, making that iron useless. You might consider taking yours apart, keeping track of where all the seals go, and reassemble using new soft seals if all the hard seals are ok, just to make sure everything is in spec. Or you can just wing it! Either way would be fun.

Hatchet Jack

Oh, a new oil pump chain is around $35. Cheap insurance.