'77 KHL620 build.....New to community, LONGtime Datsun fan......

[77_KHL620]

Ok, so we can all be on the same page, here is the COMPLETE story of the truck.

 

A longtime friend of my father bought the truck in the summer of 1977. He was a rancher and (still is) an Oregon State Brand Inspector. He bought the truck to drive while inspecting cattle brands in the Central Oregon counties of Jefferson, Wasco, Crook and Deschutes. He drove it for years until it had an engine problem and he had the engine replaced. He bought the motor that is now in the truck in the mid to late 1980's and says it had less than 40,000 miles on it when he parked it in 2005.

 

Fast forward to April 2012. My father asked his friend about the truck. After coming to an agreement to trade 4 cords of firewood for the truck, my dad got the title from his friend who was the original owner.

 

My father took the truck to a mechanic friend in Prineville who put a new water pump in the truck, put new brakes on all four corners and replaced all the fluids. He then took it to another mechanic friend in Madras who replaced the plugs, plug wires, coil, distributor cap and rotor, and put a rebuilt Weber carburetor on it. It ran fine when it left the mechanic.

 

After about a month or so, my cousin kept asking my father about the truck. He bugged my dad and bugged my dad until my father agreed to give him the truck in exchange for $200 and he had to help my dad split 3 cords of wood and haul 2 cords. My cousin agreed to this. Unfortunately, "flake" as he is known, never delivered on his deal. After taking the truck and 'dinking' with it, it barely ran was blowing white smoke or steam from the tailpipe. My cousin said I could have the truck, and I worked it out with my father as well. I went to get the truck and had to drive it 7 miles from Culver to Madras. It BARELY made it under its own power. #2 plug appears to have been smacked HARD by something. I also found oil in the tailpipe. I have not yet drained the oil and anitfreeze to check for mixing but plan to do so tomorrow. HELP!

'

[flatcat19]

Sounds like it started out being a headgasket-then elevated to something else.

 

Are the plugs in it the ones the truck calls for?

Maybe fish a magnet through the plug hole and see what comes out.

 

Spin the engine by hand to see if there are any obstructions.

 

GL!

[77_KHL620]

Oh there is no problem with there being obstructions. The motor will start and run but it sounds like it has a hole in a piston as it is missing on one cylinder. I found a rebuid kit with gaskets, bearings, pistons rings, etc for about $250. I just have never rebuilt a Datsun motor by myself before and don't want to just jump into something without having someone knowledgeable about engines helping me.

[flatcat19]

Well-

First off, diagnose the problem before buying anything except tools.

-Buying a rebuild kit(pistons, etc.) to find that you only need a headgasket or something else is just throwing away money.

 

Second, pistons are never the same size as the hole you want to put them in.

-You can buy 85.00mm pistons all day. None of them will be the same size. Ever.

Some will be a little bigger. Some the opposite.

 

There is more to it than that. That was more food for thought, really.

I would suggest pulling the head off and see what you're working with.

After that, then you can formulate a game plan.

 

Do you have a different daily driver?

[flatcat19]

And something to watch to get you started...

 

[datzenmike]

KNOW HOW TO BLOCK THE CHAIN TENSIONER!!!!! Ask how if you don't know and save yourself a days work.

 

 

Remove the head and inspect. Look at the piston tops. Severe overheating can break the ring lands and you might even see chunks missing. (chunks that might have hit the plug)

Over heating can also cause the valve seats to loosen

[77_KHL620]

I have a reliable daily driver (2010 Sentra SE-R). And I will definetely find out what I need before purchasing anything. I have several mechanic friends.

[datzenmike]

Make sure they know about the chain tensioner.