84 85hp Say it isn't so.......................

[84force]

Been having a ongoing problem with lack of power and rpm. Finally able to get all 3 cylinders firing. Still I have the same problem as always, lacking power and low wot rpm. It was suggested that I do a leak down test. I had trouble with the equipment and failed to obtain readings during the leak down test but, something interesting happened. When I pressurized no.1 the air pressure was leaking into no.2. The more pressure applied the more pronounced the pressure leak. Is it possible that I have a head gasket leak? If so, could this cause the lack of power and the low rpms that I have been trying to correct all along? Any suggestions would be a great help.
Thanks!

 

[justin65]

Re: 84 85hp Say it isn't so.......................

Been having a ongoing problem with lack of power and rpm. Finally able to get all 3 cylinders firing. Still I have the same problem as always, lacking power and low wot rpm. It was suggested that I do a leak down test. I had trouble with the equipment and failed to obtain readings during the leak down test but, something interesting happened. When I pressurized no.1 the air pressure was leaking into no.2. The more pressure applied the more pronounced the pressure leak. Is it possible that I have a head gasket leak? If so, could this cause the lack of power and the low rpms that I have been trying to correct all along? Any suggestions would be a great help.
Thanks!

Just like car motors yes it can.
The leaking cylinders will work against each other.
I would start by replacing the head gasket. Check over the old gasket for any leak over paths. While you have the head off check the pistons, walls and water jackets out.

 

[84force]

Re: 84 85hp Say it isn't so.......................

Thanks Justin,
I plan to pull the head tonight. If the head is warped do you guys have a suggestion to how much can be removed if I have the head resurfaced? Any tips or tricks associated with the removal of the cylinder head on this application? Thanks again to everyone who has helped me we with this ongoing project!

 

[Frank Acampora]

Re: 84 85hp Say it isn't so.......................

If you need to re-surface the head, the old chrysler manuals used to say not to take off more than .010. But if you remove the head gasket and re-install the head, if you still have clearance when turning over the engine by hand, then you could go as far as .060. I have actually done this on a 15 hp engine. It ended up with 140lbs compression. On a bigger engine, you won't gain so much compression though.

 

[84force]

Re: 84 85hp Say it isn't so.......................

Thanks Frank,
I will check this out, you have been a big help and I am grateful. This is a great forum, full of great advice, and great people like you. I will continue to ask questions and look forward to the responses form all of you.