G54b 3 different heads

[nerfe12]

In my junkyard adventures I have found a couple variations for my 2.6L G54b, so I'm wondering which would be best for building decent performing truck. My truck is 4x4 so that might be a factor in choosing. My options are a Hydraulic Jet Valve head, Mechanical Jet Valve head and a Mechanical Non Jet head.
When I say mechanical and hydraulic I'm referring to the manual and hydraulic lash adjusters.
I'm not trying to pour a ton of money into it so I'm looking for something reliable and with decent power, maybe close to the 200hp range. Not sure if that's possible without strapping on a turbo to it haha
I do know that the mechanical head would take a larger cam better than the hydraulic

[geezer101]

Mechanical non jet valve head - jet valve heads are prone to cracking, the jet valves themselves can fail and if you choose to use a high lift cam, hydraulics can compress enough to negate the extra intended lift.

[pennyman1]

the mechanical non jet head - is it off a caravan / k-car, or a replacement head? There are a lot of differences between the 2.

[nerfe12]

the mechanical non jet head - is it off a caravan / k-car, or a replacement head? There are a lot of differences between the 2.


It was on a Mighty Max but the markings are the same as the Clearwater heads. I believe those are for the caravans right?

[pennyman1]

if its the same as Clearwater then it is a Clearwater, which is the better head - grab it, but be sure to untorque it the right way to minimize warping - its the reverse of torque down.

[nerfe12]

Will do, thanks pennyman1. Just one more question, are the specs for the lash adjusters the same as the head with jet valves? I've been looking around and the only specs I find are for the jet valve head.

[pennyman1]

there are no adjustments for the lash adjusters - they adjust the lash like a hydraulic lifter on a regular motor.

[nerfe12]

there are no adjustments for the lash adjusters - they adjust the lash like a hydraulic lifter on a regular motor.

Now I'm a little confused, sorry pennyman. So even though the it is has the manual lash adjusters instead of hydraulic I wouldn't have to check the clearance on it? Between the the points of contact with the valve stem?

[nerfe12]

I ask because when I took my Jet valve head to get machined the shop gave me specs to adjust it if it was ticking too much, for hot and cold adjustment

[geezer101]

Yes, you need to manually adjust mechanical tappets with a 12mm ring end wrench and a flat blade screwdriver. Preferred method is hot adjustment (they are typically noisier cold until they expand from heat cycles)

[nerfe12]

Yes, you need to manually adjust mechanical tappets with a 12mm ring end wrench and a flat blade screwdriver. Preferred method is hot adjustment (they are typically noisier cold until they expand from heat cycles)

Ok, cool. But would you guys know if the gap would be the same for the jet and non-jet heads? I can't find anything for the non-jet

[geezer101]

Hot clearances are 0.008" on the intake valves - 0.012" on the exhaust valves. Add .0.002" for setting them cold. I prefer to set them by feel hot. Just a matter of grabbing the rockers and adjusting them to the point where you can feel them barely moving with the valves closed. I find that setting the clearances with feeler gauges can be a very hit and miss affair if the rockers are exhibiting signs of wear.

[pennyman1]

I missed the prt about the non-jet head being mechanical, sorry for the confusion. I think those valve adjustments look too big to me - I thought they were .006 intake and exhaust, but I am going by Geronimo's head, and his is an early g54b motor. The manual would be the best source for the correct setting - use the 1984 valve lash adjustments, as 85 up are hydraulic.

[nerfe12]

Ok thanks guys!