Head Gasket

[RamD50]

Well today on my way to work my poor truck decided to blow its head gasket. How much work am I in for? Anything I should take care of with the head off?

[Law Dog]

Oil pump when you have it apart, the weak link of the g54b, get the head done and add studs over the old head bolts they say it prevents the head gaskets from blowing but that might be moresalesmanship rather then fact. Check the head and block most blown gaskets I have seen are from cylinder to cylinder maybe there is a fix that I'm not aware of to prevent this but it is the death of many a G54B. The last 4 I dealt with all had blown head gaskets.

Water pump also cheap investment!

[85Ram50]

Do the timing and balancer belts, water pump, and new head bolts. I got mine at a Mitsubishi dealer. I never broke a motor down before and it was pretty simple to do all that for me and help on here. Oh yea new PCV valve too maybe take the chance of having drained it of all fluids to replace a bad heater?

[pennyman1]

2.6 is chains, they can be replaced cheaply enough. Use a straight edge on the block and the head to check for flatness. Rest of the essentials have been covered.

[RamD50]

While my head is off should I go ahead and delete the jet valves? And would I get better fuel economy (and not have to jet my weber) if I went back to a factory style cam instead of the Mikuni phh cam?

[geezer101]

IDK if the cam will make that much difference with the Weber but from what I have read up you need the distributor re-curved for the whole package to work at it's peak (head+carbs+distributor+cam*) IMO you should be able to get way better economy with the single Weber downdraft 32/36 and a re-tune on the stock cam (only way to to know is doing a comparison with both the cams which is a PITA but will give you something solid to work with). I would definitely have a go at cleaning up the ports and the inlet manifold while it's off the engine. It will improve idle smoothness and throttle response. The jet valves are one of the weak links in the top end of the 4G54 engine but as I have posted before, the overall design of the jet valve head has inherent flaws that leave it prone to cracking. Removing the jet valves takes out one of the weak links.

*for the twin Mikuni PHH carbs

[pennyman1]

The stock cams are on ebay for cheap, but don't toss the mikuni cam - they are almost impossible to find.

[Law Dog]

While my head is off should I go ahead and delete the jet valves? And would I get better fuel economy (and not have to jet my weber) if I went back to a factory style cam instead of the Mikuni phh cam?


You decide to plug them jet valves get a set off Amazon they come from the same place but the shipping is 1/2 through Amazon! FYI

[RamD50]

Well I'm just getting a non-jet valve head since mine is toast, lol.

[Law Dog]

That's what I did on another one I see some come without the fuel pump slot in them, but mine had no jets with the slot but I have 2 more heads with jets in them I need to plug.