replacing Mercruiser 4.3 v6 1993 engine with Chevy s10 4.3 v6 1993

[achris]

..... Also since the replacement engine has quite a few miles, I've been told at least 120K, I'm thinking about replacing the lifters and possibly the camshaft as well. Also I would definitely like to replace the timing chain and gears. Even so Im trying to go as low on expenses as possible, Id like to get the engine in a decent shape.

With that many miles on, I'd look at the 30 thou oversize pistons and 10 thou undersize bearings. That will also mean some machine shop work. For a cam, head to crane or one of the others and get a standard RV grind (This Crane looks like it'd work nicely. HR-194/271-2-12). Lifers and timing sets should be kept standard. (Summit should have)

Chris......

 

[dlogvine]

With that many miles on, I'd look at the 30 thou oversize pistons and 10 thou undersize bearings. That will also mean some machine shop work. For a cam, head to crane or one of the others and get a standard RV grind (This Crane looks like it'd work nicely. HR-194/271-2-12). Lifers and timing sets should be kept standard. (Summit should have)

Chris......

Im going to do the inspection of the block, but based on the condition of the cylinders and pistons, I expect just to hone the cylinders, clean up the piston grooves and replace the lifters, timing kit and gaskets. Also possibly grind the crankshaft 0.001 over or just polish it.

 

[Rick Stephens]

Im going to do the inspection of the block, but based on the condition of the cylinders and pistons, I expect just to hone the cylinders, clean up the piston grooves and replace the lifters, timing kit and gaskets. Also possibly grind the crankshaft 0.001 over or just polish it.

If you do that, get your rings and slide them into each cylinder without the pistons and mic the end gaps. That will tell you how much wear. The ring manufacturers have a very specific range that the ring gap should fall into.

 

[dlogvine]

Finally I took the engine apart. The pistons, bores, lifters, cam and crank shafts are in great condition, much better than I expected. The only setback was the flywheel, I was not able to remove the bolts holding it, so Im taking the whole think to the mechanics shop to vat it, clean and magnaflux. I'll get it miked and then based on the results will order the rebuild kit. Looks like I'll just have to polish the crankshaft, it was in remarkably good shape considering the mileage (I suspect that the mileage is significantly lower than what I've been told based on the small amount of wear in the bearings and other parts). I'm thinking about using all the parts of the small block from this engine, except for the intake manifold and just change all bearings, piston rings, timing gear, gaskets and freeze plugs. Will update on the rebuild. For $100 for this engine, it is a great rebuild project. One question, is there any way to loosen the bolts holding the flywheel? I used the impact driver with 6 point sockets, PCB blaster and even tried to heat the wheel with the blow torch. Still no results. Added compressor pressure started stripping the bolts. I know that the machine shop will take the flywheel off but what could I do without the shop?

 

[Bondo]

One question, is there any way to loosen the bolts holding the flywheel? I used the impact driver with 6 point sockets, PCB blaster and even tried to heat the wheel with the blow torch. Still no results. Added compressor pressure started stripping the bolts. I know that the machine shop will take the flywheel off but what could I do without the shop?

Ayuh,.... I've got an IR2235 1/2" impact that I haven't found a bolt that small it won't remove,....

 

[Rick Stephens]

Ayuh,.... I've got an IR2235 1/2" impact that I haven't found a bolt that small it won't remove,....

Either that or a long breaker bar with a socket that does not recess the flats. Have to bolt down the starter gear.

 

[dlogvine]

I have a 1/2" pneumatic impact driver, my compressor was too weak, so I've got one from my friend. Still no results, it was going with a lot of power but the bolts were not moving and the socket started stripping the bolts... Tried to heat them up to break them free, no luck...

 

[dlogvine]

No Title

Tried a longer breaker bar, no luck - I feel that Im going to break the bolts before they will move. However on the bright side, Was cleaning pistons with Chem Cleaner - works miracles, after a couple hours of soaking carbon deposits are getting either completely washed out or get soft so I can remove them with the brush pad. Got a little scare, my friend was removing one of the pistons and it went down the cylinder and banged it on the concrete. Left a mark on the edge, however this mark does not affect the side, so the piston still could be used.

 

[dlogvine]

was working on the cleanup of carbon deposits. second time the heads were easy to take apart and cleaned up most of carbon of the pistons and Springs assembly easily. there is still some gunk on the intake channels. Retainers were removed easily, mich much easier than the first time . probably will buy a part cleaner bath and wash the whole head in it

 

[dlogvine]

after a thorough inspection, looks like the camshaft needs to be replaced, has some serious scratches. machine shop Mechanic confirmed my original guess. now I'm waiting for the machine shop to vat the engine and inspect it. today we pulled out the original engine from the boat and despite some rust on the bottom side of the engine looks like it is in a good shape, heads were immaculately clean almost like brand new, will remove the spark plugs and test the compression tomorrow. if it will show good compression, I'll just use this engine after some surface cleaning and new paint. will have to replace a couple hoses, they were hard to remove and had to cut the ends of the water hose and one other, cant remember which. Definitely will have to replace the starter and alternator, they are gone beyond any repair, distributor cap and rotor and drill out a couple rusted out broken bolts. will see how much work needs to be done tomorrow

 

[dlogvine]

I checked the compression in the cylinders of the original engine. The readings were not good, 1 cyl 150psi, 3 cyl 95psi, 5 cyl only 60, 2 cyl 145, 4cyl 120, 6 cyl 82psi. I wonder if there could be another explanation besides the bad piston rings? I have a suspicion that the head gaskets are in bad shape and leak that causes the compression to go down from the front to back cylinders. My friend is convinced that it is the rings problem, but considering low hours on the engine, good oil and no water inside the engine, I am not convinced that the rings are the problem.

 

[Bondo]

Ayuh,... A leak-down test can tell ya whether it's the rings or the valves,...

 

[dlogvine]

Thx Bondo, I decided to take it to the machine shop, to test it all and magnaflux it. Also there were a couple rusted out broken bolts, that I failed to remove and the flywheel is stuck pretty well. Let them do it all.

 

[dlogvine]

I looked at the intake manifold, it has a fuel injector setup, not a carburator, like the original boat one. Could i use this intake manifold and what should i change to make the engine work with the fuel injection instead of carburator.

 

[Bondo]

Could i use this intake manifold and what should i change to make the engine work with the fuel injection instead of carburator.

Ayuh,.... Wirin' harness, injectors, 'puter, etc.... Probably a few thousand bucks worth of accessories,....

 

[dlogvine]

Ayuh,.... Wirin' harness, injectors, 'puter, etc.... Probably a few thousand bucks worth of accessories,....

Question answered, thx, definitely not worth it. Will just find a decent quality and price intake manifold online from mercruiser 4.3 and use it.

 

[Rick Stephens]

Go get an Edelbrock Performa. I believe you want the 2111. Find it at Summit and other places.

Rick

 

[dlogvine]

Go get an Edelbrock Performa. I believe you want the 2111. Find it at Summit and other places.

Rick

Too expensive + Ill have to get a different carburator, this is the restoration budget project and not my own boat. Im trying to get it done as cheap as possible. And I saw a couple regular cast iron 2BBL intake manifolds on ebay for under $150. Or if I decide to go with quadrajet, there are a couple for under $200, or one with the carburator and thermostat housing for $330.
Thank you for an advice though, if it was my own boat, Id have done exactly that

 

[dlogvine]

I took both engines to the machine shop and after almost a month of them dragging their feet in inspecting the engines, today I got the results of inspection. I am very suspicious about the results, because on both engines they have almost identical problems while the marine original engine had barely 250 hours and the replacement from chevy S10 had more than 100K miles. The results said that both engines have cylinders with gap exceeding 0.0010 inch (requiring new boring and expensive procedure), both heads have weak springs, blocks required resurfacing the head connection surfaces and couple more very similar in both engines results, I dont remember exactly which, but will get the detailed analysis tomorrow.
The question I have is the following, since I dont trust this mechanic much (he did lie about the time frame of the inspection on multiple occasions, from week and a half original estimate to more than a month in final, and other little lies), how can I make sure he is not lying about the results of the inspection just to get more money for the job not needed? I can take it to another mechanic to remike all the parts but this will cost extra money. Could I ask him to remeasure the questionable parts in front of me,so that I can compare the results? Or any other suggestions? Thank you

 

[Rick Stephens]

Only way to be sure is take it to a difference machine shop. Kind of a mess to try that now.