Cylinder block compatibility 1150

[Shfftr]

I just picked up a 69 Starcraft with a 1977 merc 1150. I bought it knowing there was no compression in #3 cylinder. I understand that happens often due to running lean creating too much heat. Fearing the worst I searched for some used cylinder blocks. I found several. My engine calls for block#7401A2, I have run across several blocks #6192A1 and 6432A1. I believe the 740 superseded the 643 which superseded the 619. I would like to know if 619 or 643 would be a useable block for my engine. Thank you for any help. Steve

 

[Chris1956]

Re: Cylinder block compatibility 1150

It is probably the same amount of work to replace the block, versus repairing your block. Is she only needs a boring and 1 piston for #3, you might just repair it.

In both cases you need to figure out what caused the problem in the first place and repair that as well. If it were me, I would rebuild the waterpump, fuel pump and all carbs. Do a link and synch and that should fix any issue.

 

[Faztbullet]

Re: Cylinder block compatibility 1150

I understand that happens often due to running lean creating too much heat.

A bad trigger will do this also......

I would like to know if 619 or 643 would be a useable block for my engine.

Those are early model blocks and a few differences are the starter and mounting ,carbs as real early had KD carbs and studs are straight across and WMK are staggered, Earlier models had different fuel pumps(held with screws not 1/4 bolts,fuel pump mounting location,bleed and balance routing differences and real earlier the exhaust is like a letter "D" and not 2 separate ports. Also most used blocks will need boring as they wear out a taper at intake /exhaust port even though the cylinders look fine. They only way you can tell is to mike the cylinders or the quickest is to run a rigid hone down cylinder and the wear areas will be dark and untouched.

 

[Shfftr]

Re: Cylinder block compatibility 1150

I would like to thank both of you for your advice. I am going to pic it up tomorrow,hopefully the PO can give me as much in information leading up to the problem. That may help in diagnosing what happened. I won't purchase any possible replacement parts until I can get into the engine and see what can be repaired or possibly replaced. I see I have a lot to learn. I believe I will have my work cut out for me this winter.

 

[Chris1956]

Re: Cylinder block compatibility 1150

Shiftr, If you can do the work yourself, a repair of one cylinder is about $200-$225. I did not include carb, waterpump or fuel pump repair costs, since you need to do those anyway you proceed.

 

[Shfftr]

Re: Cylinder block compatibility 1150

I believe I can do the work other than bore cylinder if needed. I hope it is still salvageable with a simple honing and some new rings and piston. If it has to be bored,might be hard to find machine shop to do the blind bore. Hopefully,able to start in it this week and see the damage.

 

[wired247]

Re: Cylinder block compatibility 1150

You can still find the occasional "new" NOS or service block for $500-$1000 . Sometimes less. Depends how much you like your current motor.