Pistons for D 318 with heat plug?

Looked through all my D318 stuff including the #14 Grader with turbo (140 hp) and also Series "G" engines and none of them show a heat plug piston. If they exist they may have been after market.
Rack settings can be adjusted to accommodate turbos but usually require matching governor and governor spring changes.

My D69U 318 has at least one non standard piston, one oil ring others have two oil rings no heat plug. Can't recall any mention of two piece pistons in 318 I don't want them too many part company.
Only have three out so far will be interesting to see what is in the other holes sorry not much help to you but someone may know of piston options.
wimmera farmer

Those pistons were offered by M&W many years ago. They were part of a high horsepower kit. I know a guy that put them in his 6. Worked great for about 5 years then the plugs started to come out of the pistons. He ended up pulling the head and welding all of the holes shut. It is still running with those pistons. I dont remeber any more than that. I was pretty young at that time.

Thanks guys for the info. I have a turbo for the machine but not sure how to adjust the rack settings to compensate for it. Will the after market pistons hold up to the turbo if there is enough fuel fed to the engine?

Might want to read up on this conversion instruction sheet for the time.
I would assume late rods were slightly beefed up and the late pistons were the cam shaped units. The older piston/rod combo required 0.020 higher rack settings (according to my rack setting charts).

Lots of these units died from rod and rod bearing failures if abused.

Pistons are one part of engine design that has been upgraded time after time, until there are virtually dozens of piston designs and part numbers for one particular engine.
Aftermarket manufacturers redesign Cat piston design .. or use obsolete Cat piston design .. to get around patent and "registered design" infringement claims.

Design improvements for pistons have typically been ..

1. A regular reduction in the number of rings to reduce friction and improve power output. Ring numbers over the period from the 1930's to the 1960's went from 5 ring, to 4 ring, to 3 ring.

2. Redesign of ring shapes and material of construction. There have been numerous different ring designs and materials used.

3. Cast iron inserts in pistons, to improve piston and ring life. These started appearing in the early 1950's.

4. Heat plugs in the center of piston crowns. Cat started using these in the mid 1950's.

5. Cam-ground pistons, designed to make the piston conform more accurately to the bore when at operating temperatures. These appeared in the early 1960's.

Cat commenced using heat plugs in pistons in the mid-1950's .. right about the time the first turboed Cat engines appeared. It was found that the increased combustion temperatures of turbocharging, along with increased fuel supply (rack screwed up for turbocharging) caused piston crowns to start to melt at the point where the hot gasified charge from the precom and injector met the piston.

Stainless steel heat plugs were fitted by Cat engineers at this point in the piston crown, to absorb the concentrated combustion heat. Cat settled on bolt-in heat plugs, as they can absorb variations in dimensions that can vary from the aluminum material in the piston, when combustion temperatures vary widely.
Some aftermarket manufacturers tried cast-in heat plugs, which made pistons prone to cracking in the heat plug area.

Ask your engine kit supplier for pistons designed for the turbo D318. If you do not use pistons with heat plugs in them, and you add a turbo, you risk piston failure under heavy load. You should also fit piston cooling oil jets .. these are a vital part of piston cooling in turbo engines, and there has not been a turboed Cat engine built in the last 50 years that doesn't use piston oil cooling.

Your Cat dealer should be able to supply the P/N for the pistons with the heat plug, and you should then be able to cross to an aftermarket P/N. I always found that genuine Cat pistons performed better than aftermarket pistons, and they often weren't much dearer.

Yes, you need to screw up the rack when you fit a turbo, to increase fuel delivery, to take advantage of the extra air supply being pumped into the engine.