The engine in my GSL-SE is starting to show it's age, so will need to be replaced in the near future.

I've read in the 2nd Gen forum about S5 engines being put into S4's. This thread is questioning about putting a S4 engine in what I guess would be appropriate to call a S3.

I have access to a S4 engine that I know is in good shape and only has about 30,000 miles on it. If I were to change out the front cover, oil pan, and use a S4 counterweight for my lightened steel flywheel, can I otherwise just bolt on the GSL-SE intake, exhaust, etc. etc. and drop it in?

Thanks in advance for sharing your 1st Gen wisdom.

 

Yes.

The ports are *slightly larger and will match up with the GSL-SE intake about 97%. It will bolt on, It will work. I've seen it myself.

 

All this "S5", "S4", "S3" stuff is confusing me...Someone translate?

~T.J.

 

the only thing that i can think of is that you may need a block-off plate for the center housing. i don't know if the SE manifold will clear that thing (i don't what it is EGR ????) ... but yes, the engine will work.

 

Series 1 = 79/80 Or SA22C
Series 2 = 81-83 Or FB
Series 3 = 84/85 Also FB
Series 4 = 86-88 Or FC
Series 5 = 89-92 Also FC
Series 6 = 93 + Or FD

 

Well, Series 6 = '93-95, Series 7 = '96-98, Series 8 = '99-current

 

Ok, I knew the first gen series', I just didnt know anything else. Thanks .

~T.J.

 

Thanks to all. Hope to return the favor sometime.

 

Don't the 2nd gen engines have different oil injection set-up also? They have 2 oil lines going to the lower intake manifold and 2 to the rotor housing, correct?

 

Yes, you just use 2 of the the GSL-SE injector lines to the rotor housing,and you can "bridge" the other two outputs (to each other) for higher flow.

That's how I am doing the Cosmo.

 

Directfreak, I thought the other 2 oil injector lines going to the manifold were to lubricate the side seals. Would it not be better for him to just block off the damn omp and use premix?

 

You could do that, but remember when you use premix, you always have to set it for HIGH RPM Use (5% of the time). So it will always be running real rich and fouling plugs, etc the other 95% of the time. This is why you see many 7's with smoke/black marks out of their exhaust onto the paint of the cars too.

For a Race car - Premix is the only way to go. I am still not 100% sure I am not going to just pre-mix myself. My car will be driven about once a week only. So it might make more sense to me for the worry-free aspect of it.

 

Wow, you just reminded me of something... remember the MSD thread where everyone was on my case because my carb was "obviously" "tuned wrong" if it would consistently foul plugs in subzero cold start situations?

Well, I completely forgot that the stock engine had a dead OMP and that I was premixing 2-cycle oil to the gasoline at 1:128. That might have caused some plug fouling issues under extreme conditions

Too lazy to dig up the old thread.... yeah, let's just let that sleeping dog lie.

 

Ha!! Interesting...

 

Peejay, what was the ratio you were using?

 

1:128. (See above)

Or, one ounce of oil to one gallon of gasoline.

The OMP on the 12As goes from about 1:150 at full throttle, to about 1:400 under low load. As Directfreak pointed out, when you premix you have to go about as rich as the engine will ever need, so it never has insufficient oiling. The rest of the time, "so what?". In truth, I'd never actually figure "well I'm putting in X gallons so let's get out a measuring cup...", I just dump in an 8oz bottle when filling the tank, which would be anywhere from 7gal to 10gal. Most I ever was able to put in the tank was 13 gallons when I ran it dry once - used TWO bottles that time

 

One thing no one mentions in the omp vs premix debate is the lubricating properties of the oils. Motor oil may not burn as well but it probably lubricates better than 2 cycle oil in the same ratio, you think?

 

Not if the oil youre buying is "real" 2 cycle oil. Thats the whole purpose of 2 cycle oil, to lubricate...Not just be in there to be burned . I would say that 2 cycle oil will lubricate the same (if not better) than motor oil, and it definatly would burn cleaner seeing as how its designed to be burned .

~T.J.

 

Hmmm. It may be flawed reasoning, but: the more you get on the throttle, the more fuel is injected, and so the oil quantity is increased. The ratio would not be too rich at low rpm, the amount injected is automatically reduced. Similar to the OMP; it is connected to the throttle linkage and injects more or less, depending on the rpm. Like the premix, it's also always the same ratio also, i.e. 100%.

In other words, the richness of the premix is also self-regulating. Just a thought.

-John.

 

Well thats not quite true. Thinking, but not completely through.

The ratio of gas to oil remains the same in premix usage. Volume oil to volume gas. One ounce oil for one gallon gas as peejay stated 128:1. ...is the same at any larger or smaller volume going into the engine. Were as the metering system changes with throttle position. Whatever Peejay said 150:1 to ?400:1?. I know that if you add 16gallons gas and add 16oz of 2cycle oil to the gas, thats A LOT more then you add to the engine oil pan when you have to add because of the metering system drained some out!!

 

The factory OMP setup varies this. At low load, it only injects 1 part oil to 400 parts fuel. Even though the fuel is reduced, the OMP reduces oiling even more. The engine requires propertionately less oil at lower load.

So, premix is always a compromise... either it's too rich at low load, or it's too lean at high load. So what you do for safety is go for what you need at high load. Being too lean means increased engine wear, being too rich just means, oh, say, reduced spark plug life and increased chance of fouling-out.

I'd rather go with premix, though... 2-cycle oil is, by its very nature, DESIGNED to burn completely, and is designed to lubricate surfaces well when it is heavily diluted by gasoline that is atomized in air at a ratio of roughly 1:30,000 by volume

 

Interesting.

I missed that part, obviously. I had thought the OMP output was reduced 1:1 with the throttle.

Yes, it is a little more, isn't it. Perfectly obvious, now that you mention it, and shoots a rather large hole in my theory, doesn't it?

Thanks, Guys.

-John.