Mercruiser 3.7 Build, 1970 Cj5? Part 2, Fab And Adapting!

This is bad. Coolant into the combustion chamber, or an external leak, shouldn't hurt anything else. But coolant in the oil, if the leak is severe, could wash down the bearings and lead to total engine failure.

 

With fresh flat metal on both sides, and no plans of overheating,the compression will seal!
Water and oil mix should be avoided by the sealant around all the holes in head gasket, I hope.

Last sleeve on cam, getting ready to put cover on.

 

Those holes in your head gasket with all the raised sealing beads fall in the open deck of the water jacket on your engine. There is no block deck to compress against to seal. The leaking occurs between the open water jacket and the pushrod galley. The Mercruiser gasket has a raised sealing bead along this whole surface between the two.
-Donny

 

There is a lot that still can be done without the head gasket in place.
I have to agree that the head gasket with the Ford beads will be hard to seal with the open deck as the crisscross of the deck on the beads is going to create paths for coolant to escape and that just isn't worth the risk.
Whatever time it takes to get the right part is time well spent.
I have a 4.3 that I built in my jeep.
Mild cam, light weight flat top pistons. 3 days in a circle track engine shop getting everything neutral balanced... and in 5 years it has gone 10miles down the road under it's own power; because a loose needle bearing broke a tooth in the Transmission. I knew I lost the needle somewhere because I have the replacement still in its bag I just assumed it would be fine. Now I have enough issues with the Transmission to justify a sm465 swap. That needle bearing was less than a dollar. But I had myself believing the jeep needed to run for my wedding just to hold the sign by the highway "turn here for _ and _ wedding". Totally not worth rushing or substituting for the right part.

 

The marine engine is sealed up way better than our car versions.
Factory manual says use this perfect seal almost everywhere, and I'm doing so.
And over 30, 5/16 pan bolts, every 2-2-1/4 in all way round.
Gaskets were nice and thick also,
Cork gasket on pan, adhieive peel off on 1 side.
I have a thick and a thin fuel pump gasket.
I've left my pump at Napa for them to cross to a 16$ pump instead of the 70$ original.
Head back Monday. Hope to have rest of short block done by then.

 

Carb apart and in soak tank.

 

Ready to install.
I opened the mains up with my jet reamer just a tad to compensate
for the gas of today, also reamed the squirt hole a tad.
Float set a little on the low side, for off road sloshing .
I will eventually extend the bowl vent.

 

Getting closer.
6 of my 8 lifters went in fine, 2 were bad in the box?
1 was too large, would not go in hole, 1 was so small it rattled ,side sways in hole?
New sealed power brand. Parts these days?

 

Setting up valve train.
Had .028 took off deck, .015 took off head.
Had to shim pedistal rockers, to get preload right.
Shim kit came with, .019,and .035 shims.
After several trials, 1 of ea seemed best, bout .054.
After I felt drag on push rod while rotating, 7/8 to 1-1/4 turns preload on lifters.
Then torque to 20 ft lbs.
Hope to start on a engine start up stand by the weekend?
Got a retorqued head after run to operating temp,(bout 20 min).
Santa needs to bring me a shorty header? LOL.
Their center exit, I think I can use either side ok?
Anyone want the other side for a future project?
I sell for half my cost on set plus shipping.
Cost 120$ set.
So 60$ , + ship?

 

Looking good! Did you decide on the short t-90, long t-90, or SM-465?

 

Ant decided yet?

 

Just tidying up loose ends tonight, fuel line, pump to carb.
Throttle linkage.
Spark plugs.
Dip stick.
Then prime oil.
Then distributor?

 

Getting good

 

Dare not ask about dyno sheets this time of year, but just curious what torque/hp numbers you are shooting for or expecting from this build? Very interesting design and application, so I am looking forward to see where this falls among the other more common power plants. I apologize if this was mentioned somewhere in the thread or previous thread, I may have missed it.

 

Just thinking about the exhaust header you mentioned previously. With the engine setting on the stand the exhaust flange is verticle as opposed to the V8 angle. If a header designed for a 460 is bolted on, it will stick out away from the engine instead of tuck next to it. You may have thought about this but haven’t mentioned it.

 

These 470's are rated at 165-170 hp in 2bbl form, with about 270 ft/lb torque. Reletively compact and light weight, they are an interesting unusual engine.
-Donny

 

Hope to be around 200hp. But don't really care, torque is what I want.
The head work, header, and compression increase, should raise the stock numbers slightly.
Big torque, under 4500 rpm, should make a great off road engine?

 

The 4bbl version has a hotter cam which is what brings the horsepower numbers up on these engines. Yes, these have huge torque down low which should make an excellent off-road powerplant. I can't find the torque graphs from way back, but most of the full torque was in by 2000 rpm. Almost diesel-like!
-Donny

 

Those peak numbers are very close to the 4.3s. Stock My 4bbl1985 4.3 is only 155hp at 4000 and 230 ft lbs at 2400rpm. The later non turbo 4.3 was 200hp at best with 260ft lbs @ 2800rpm.
To make the same power and more torque with 2/3 the parts is darn neat.
Better yet It is likely 2/3s the weight of my iron v6.

General Motors 90° V6 engine - Wikipedia

 

So how does this 3.7 compare to the dauntless 3.7 ?
Ps the striped block was bout 65lbs? Felt bout same as the head?
Bet this engine weighs no more than my 134?

Funny story.
Before the distributor went in, I primed the oil system.
Next day saw a drip or 2 on ground,looked at engine and the pan bolts were still
Only snug so they would not push gasket out, so I tightened them up, wiped off pan, and thought I was done? Next day, drips on ground again,looked at engine and, no rear main seal.
When I primed the oil it pushed out around the rear main.
Went to gasket pile and no seal? Looked over an hour, still no seal.
Decided it was time to clean up some of my mess, had not put up any tools since I started the build over a month ago. Got most put up when the wife calls me in for lunch.
Had a half drunk,warm,mt dew, went to drop it off in the freezer on way in and
Their it was, in the freezer, I had put the seal in to shrink,when I opened the gasket kit.
My short term memory, ant what it used to be?