1990 vs 1992 4.3 block swap

[Chris51280]

Awesome. I will do that. The only thing I have not watched out for are the lifters. Since I'm getting a different cam, I hope that won't be too much of a problem. Thanks for all the clarifications. I marked all the pistons where the go to and left the rods assembled. The chain from the mercruiser is a single roller chain and has 1/4" slop. The chain from the car is the link chain and streched. I think I can use the roller chain and be fine. It's within spec. i know that I should change it but I try to keep my budget low now. I'm in at 450 just for parts. Still got to do the stringers and floor. Who knows what else will come around. I would want to rebuild the carb and the trim cylinders.

Thank you for the info chris. Will post the progress here. Cam should ne here January 2nd

Merry Christmas

 

[achris]

If they are roller lifters, no problem as the retainers keep them aligned.

If you're carrying the chain across, take the sprockets too.

Chris......

 

[Chris51280]

So i cleaned the heads today and lapped the valves. I noticed a small nick at the top left where the combustion gasket ring will be. It was there when I took it off since im sure I did not cause this. I have noticed that the gasket in the merceuiser was a thin stainless steel sheet vs the automotive thicker gasket. I do have the one from the car but have more sludge on them. I would just change out the one that has the nick.
i have noticed that my mercruiser engine was rebuild at some point since it is .03 over and the crank is underside as well.
This brings me to the question, if someone would machine the heads, how would i know. Im afraid I replace one head that was machined with one that was not possibly. That would create different compression ratios.
I tested the compression before I took it apart and it was at 150 on all cyclinder

 

[Chris51280]

Got most of my order from summit today and started assembling things. I checked the gasket design and it seems i won't have a problem with the little imperfection. I should also be ok with the oversize bore as described by felpro.
installed all of the freeze plugs but one. I have to install the cam bearing first. This way its easier to install the one on the transmission side without the plug right next to it.

 

[Chris51280]

I assembled the cam bearings and the crank bearings and assembled the cam and crank. I checked the piston ring gap and cleaned the piston grooves. Top ring has .018" and second .02". Its on the high side but still within spec. The underside of the piston has alot of carbon build up. Not sure if it makes a difference. I was able to use the heavy crank instead of the light crank from this engine. Will use the damper that came with the crank.

 

[Chris51280]

Got all pistons in. New rings installed. New double roller chain which is very tight, but I believe will stretch anyways. One cylinder head down with the bolts sealed. Need to get another permatex tube. 0.2oz lasted only for one side.

 

[Chris51280]

I got a small problem. The dipstick has a hole. It is right where the block had cracked and it must have sprayed water on It for some time. What can I do to fix this? Are there tubes available that can be formed? The GM one is for the car and bend differently. I may be able to repurpose the one fron the car and make it work.
the elbow is probably on its last leg and a good thing I looked into it as well. I could mill across and get a nice squared face again

 

[Scott Danforth]

buy a new dipstick tube from mercruiser

 

[achris]

buy a new dipstick tube from mercruiser

nla...

 

[Chris51280]

I found some that are +$100. fleabay wants $80 for a used one. No way I spend that much on a piece of tubing. I figured I get either 3/8 copper tubing or get on mcmaster carr and get some thin walled steel tubing for $20 and make one myself.

 

[Scott Danforth]

I found some that are +$100. fleabay wants $80 for a used one. No way I spend that much on a piece of tubing. I figured I get either 3/8 copper tubing or get on mcmaster carr and get some thin walled steel tubing for $20 and make one myself.

if its a tube that goes to a fitting in the bottom of the pan, easy to make

if its a tube that gets pressed into the block, its a bit more difficult

you either need to make sure the tube goes all the way to the bottom of the pan so you can extract the oil, or you need to install a remote drain hose

remember, oil dip-stick tubes are flared where they press into the block

you can also acid dip your current tube to clean the rust, then patch it by soldering a section of copper tubing over the hole.

 

[Chris51280]

Here is what i did. I filled the oil pan with 4.5 quarts and it turns out it is the exact level to the baffle. This equals to about 4" from the pan rail.
I drilled the hole open with a 3/8 drill bit since the original tubing was at .365".
I got myself 3/8" tubing and matched the old tube as good as possible. I made the 90degree radius a little bit bigger so the dip stick has an easier curve to follow since the old one had a bigger diameter in that area.
then I made sure that the bottom of the tube is very close to the bottom,of tve oil pan which was about 8.5".
I checked with the dip stick in the tube where my full line is with 4.5 quarts of oil in the pan and cut the beginning of the tube.
the only thing I don't have is the garden hose adapter. I can still get a 3/8 tubing over the dipstick tube and suck it out this way.
i will use a little rtv to seal the gap between the tube and hole

 

[Scott Danforth]

you could simply braze the tube to the block there

 

[Chris51280]

Not sure if my skills allow for that. Lol. Its already a tight fit and pretty sturdy. Don't think it will go anywhere.

 

[Chris51280]

Ok. Installed oil pan and offline oil filter. Filled up oil and tested the pump with the left over distributor minus the gear. I attached the drill to it and turned it clockwise. Then I forgot to plug the oil pressure sensor. What a mess. After it was plugged I checked that all my rockers get oil pumped. All good

 

[Chris51280]

[No message]

 

[Bondo]

Ayuh,....... Lookin' Good,.... Can't wait to hear it Roar,......

 

[Chris51280]

So it looks like an engine again. It is slower now and I have to check my pictures to see where some of tge wiring goes.
I also rebuild the mercarb yesterday with help from MadProps .
my question is, what is the center power valve for? How does that work with the air horne? With the plunger sitting on Top and depressing the needle, more fuel gets into the engine, correct? When,does the needle,close and what makes that plunger retract?

 

[Scott06]

Vacum operates the plunger ... high vacum means throttle is not open very much, little to no vacum when at WOT, valve opens up to riches the mixture as needed for full power

 

[Chris51280]

Exhaust manifold is on. Carb is on and the choke works again. It was stuck open when I got the boat. More wiring finished. New spark plugs are in.

So what is the latest on the gasket between the manifold and elbows? Some said leave it painted, some said to take the paint off. The gasket material is graphite. I think I will put some aviation gasket between the exhaust and water jacket. I know it says to install dry but what does it hurt? The sealant can withstand 400f and will not dry out.