Engine swap (repower)

[ddbyrd3]

Re: Engine swap (repower)

Do you have the chart, or data that you used to determine that? Or where can I get it?

 

[Dhadley]

Re: Engine swap (repower)

The J140 is obvoius. T means tilt & trim, X means X-long (25") and CI is 1981 using INTRODUCES with I = 1, N = 2, T =3 etc to S = 0

 

[Dhadley]

Re: Engine swap (repower)

Oh -- the last letter means basicaly nothing in the field unless the parts manual specifies it. It has to do with production runs and any changes made mid model year.

 

[ddbyrd3]

Re: Engine swap (repower)

Well I am glad I asked.... I was looking into mounting a 1987 150 V6 but it has a 20" shaft. Are the mid sections, and lower units swappable between a 1981 140 and a 1987 150????

 

[Dhadley]

Re: Engine swap (repower)

Anything can be done but there would be a lot of fabricating involved. Its not a direct swap type deal.

 

[ddbyrd3]

Re: Engine swap (repower)

I didnt think so.. Time to do the compression check on the V4 and get to the root of the power problem..

 

[kirkland]

Re: Engine swap (repower)

Just make sure boat is securely fastened to the trailer (might want to put extra ratchet straps around boat and trailer) and have someone film it so if it does go wrong you might win 10K to pay for the adventure....

 

[ddbyrd3]

Re: Engine swap (repower)

Boy wouldnt that be a sight... <br />Boat off of trailer, sitting in the back of my Suburban....

 

[kirkland]

Re: Engine swap (repower)

Guess i should have went to page 2 before replying to this post.... my bad

 

[ddbyrd3]

Re: Engine swap (repower)

OK, just completed the compression check. I am happy to report that cylinder #1 was 110<br />#2 was 115 #3 was 109 and #4 was 110.<br /><br />Based on these findings, would it be reasonable to verify the head gaskets?<br /><br />There is a section of head gasket that I could measure for thickness if anyone know the measurement of the low compression verses the standard.<br /><br />If not, what would be the next step???

 

[Dhadley]

Re: Engine swap (repower)

Did we verify the timing? If I remember right you were going to check it under a load.

 

[ddbyrd3]

Re: Engine swap (repower)

I havent had time to verify under a load just yet.. hopefully in the next couple of days.. Do you know the standard head gasket thickness? There is a small portion exposed that I was going to measure with a set of calipers just to see if I need to look at the head gaskets. Or based on the compression numbers di I even need to worry about that?

 

[ddbyrd3]

Re: Engine swap (repower)

UH yea,, the cough at idel is nearly gone. When I increaded the timing those 2.5* the idel rose just a tad. I believe it was 1000RPM no load on the trailer. I brought it down to 800 under the same conditions by re-doing the synk & link adjustment. It is much better now..

 

[ddbyrd3]

Re: Engine swap (repower)

OK.. I have another question. I called Sierra (Head gasket supplier for iboats) and asked them for the head gasket thickness between the standard head gasket p/n 18-2956 and the low compression head gasket p/n 18-3898. <br /><br />They informed me that the STD gasket was .057 thick and the low compression gasket was .060 thick.<br /><br />My question is; can a mere .003 make that big of a difference as far as effecting the compression???

 

[Rudy Brown]

Re: Engine swap (repower)

I wouldnt think .003 would make any difference.

 

[Dhadley]

Re: Engine swap (repower)

The standard OMC / BRP gasket is about .045 and the thick one is about .060.

 

[ddbyrd3]

Re: Engine swap (repower)

WOW .045 is a bit smaller than the .057 I was told by Seirra. Now .012 thats a different story.. That appears to be considerable..<br /><br />What do ya think DHadley?????

 

[Dhadley]

Re: Engine swap (repower)

We ran motors with the standard and the thick (OMC) gaskets and really didnt see much, if any, difference. The only reason I'd run a thick gasket is if the block or heads have been cut too far.

 

[ddbyrd3]

Re: Engine swap (repower)

I still need to verify the timing, I will do it this weekend, should I consider changing the head gaskets at all???

 

[Basscat 1]

Re: Engine swap (repower)

Not with that kind of compression I wouldnt.