6.5 NA Top End Rebuild w/ pics

[Axleman]

Here are some pics of the top end rebuild that we are doing in my 94 H1. I blew a head gasket over the New Years weekend. These pics were taken with my Hitachi PDA phone, so the quality is only so-so.

After the hood had been removed.


Doghouse and engine cover removed.


Cooling stack removed.


Engine, after accessories were removed.


The top end is off.


The cylinder in the front is the one that was affected (#2). The white specks are remnants of Block Seal that I used to get home.



Close up of right cylinder head (#8). Note the small crack between the valves. However this wasn't the problem...


This is the cylinder where the head gasket leak occurred. The head is corroded away, valves are awful. On the far right you can tell where the gasket failed.



This is one of the new heads I got from Alabama Cylinderhead.


The right cylinder head is installed. If you ever have to do this yourself, it is MUCH easier to install the exhaust manifold, injectors and glow plugs on the head BEFORE putting the head back on.


Both heads are on and torqued.



I'm replacing the injection pump and many of the accessories as well. I'll post more pics as progress is made.

Scot Smith
1994 HMC4, Locked
"They're right, Wider IS Better..."
Southern Axle & SteeringRemanufactured Driveline & Steering Parts for Hummers

[Axleman]

Here are some pics of the top end rebuild that we are doing in my 94 H1. I blew a head gasket over the New Years weekend. These pics were taken with my Hitachi PDA phone, so the quality is only so-so.

After the hood had been removed.


Doghouse and engine cover removed.


Cooling stack removed.


Engine, after accessories were removed.


The top end is off.


The cylinder in the front is the one that was affected (#2). The white specks are remnants of Block Seal that I used to get home.



Close up of right cylinder head (#8). Note the small crack between the valves. However this wasn't the problem...


This is the cylinder where the head gasket leak occurred. The head is corroded away, valves are awful. On the far right you can tell where the gasket failed.



This is one of the new heads I got from Alabama Cylinderhead.


The right cylinder head is installed. If you ever have to do this yourself, it is MUCH easier to install the exhaust manifold, injectors and glow plugs on the head BEFORE putting the head back on.


Both heads are on and torqued.



I'm replacing the injection pump and many of the accessories as well. I'll post more pics as progress is made.

Scot Smith
1994 HMC4, Locked
"They're right, Wider IS Better..."
Southern Axle & SteeringRemanufactured Driveline & Steering Parts for Hummers

[Buckeye Hummer]

That's like watching the surgery channel.

Thanks axle.

Jason

[Black H1]

How far did you drive with the stopgap sealer in place and did it cause any more damage?

[Axleman]

We had to drive about 120 miles after the gasket blew out. I put 1 bottle in before we left. We had to stop frequently to let the water cool down and add a gallon or two. About 90 miles into the trip, we were having to stop every 5 miles or so to cool off. I put in a second bottle and drove the last 30 miles without stopping. The block seal didn't do any extra damage, in fact we probably wouldn't have gotten home without it. I have heard of other Hummer owners that used this product at an earlier stage of failure and drove for months afterward before making repairs.

Scot Smith
1994 HMC4, Locked
"They're right, Wider IS Better..."
Southern Axle & SteeringRemanufactured Driveline & Steering Parts for Hummers

[Axleman]

Here are some more pics.

The old timing chain had a lot of slack in it, so we installed a new one.


Then we put the cover back on and attached the injection pump.


This is a close up of the rebuilt injection pump I got from Taylor Diesel in Nashville. With 150,000 miles on the engine, I figured it would help to restore some power. I also put in new injectors made by Delphi Automotive.


Here is what the fuel lines look like.


More in a few minutes.

Scot Smith
1994 HMC4, Locked
"They're right, Wider IS Better..."
Southern Axle & SteeringRemanufactured Driveline & Steering Parts for Hummers

[Axleman]

Some pics after installing the intake manifold.




We are stuck now waiting on more parts, so I'll have more pics in a few days...

Scot Smith
1994 HMC4, Locked
"They're right, Wider IS Better..."
Southern Axle & SteeringRemanufactured Driveline & Steering Parts for Hummers

[Axleman]

Tonight, I put on the new hi-flow water pump. My old water pump was rated at 85 gpm, the new pump at 130 gpm (!). The kit came with a new crossover pipe with dual thermostats like the later model 6.5 turbos. Dual thermostats are needed to handle the increased flow rate from the pump. The thermostats provided in the kit are Robert Shaw super-duper special 'stats set at 180 degrees. The kit came with a new bracket for the throttle linkage. I also purchased a specially calibrated fan clutch that operates at a lower temp than the stock clutch along with a 9 bladed fan. These kits were obtained from Kennedy Diesel

Jerry Hedger from Independence Hummer in Charlotte, NC is sending me a kit that uses the currently blocked off water jackets on the two rear cylinders. He uses very high quality components in his kit, including stainless steel braided hoses. This kit fits both NA and Turbo engines. In the stock setup, coolant is not circulated well or at all at the rear cylinders, as evidenced by both of the rear cylinders in my old heads having cracks between the valves. The addition of the kit will allow coolant to circulate in the rear of the engine and help to keep head temps down. I suspect after making these cooling upgrades, I may have to do like the big trucks and close off the grill to let the engine warm up in the winter!

I'll post some pics of the new parts in a day or so.

Scot Smith
1994 HMC4, Locked
"They're right, Wider IS Better..."
Southern Axle & SteeringRemanufactured Driveline & Steering Parts for Hummers

[DURAMAX TIM]

Since u were right there I'd have looked into an aftermarket bump stick (cam), some extra power is usually handy.

Yell'r 04 Lux w/ air, sunroof,F&R brush bars
04 Chevy D/A CC SLT LB

[Axleman]

Sorry, I haven't posted here in a while. Actually, I am now installing a rebuilt longblock with goodies such as what you suggested. I also installed a front locker and have added a separate hydraulic pump to run the Milemarker winch.

[cinci]

Axleman,

I am just installing a Milemarker hydraulic in my H2, due to the same issues that most install it in the H1, namely better approach angle due to its smaller size. However, I would be interested in your seperate pump setup and any performance inprovements that you see. I have seen some of your posts on this on the HML.

[Axleman]

When I get it worked out, I'll let you know.