weld cast iron head?

[zed]

My machinist friend here in South Africa is good at his job. But, he says he can't weld the combustion chamber of my 3F Landcruiser head, because this will cause it to warp.

I want to weld the head to reduce the big combustion chambers, to increase compression - which is real poor, like 8:1 stock. I've read on the 'net of iron heads welded up to raise compression. Is he right? Any tips if he's wrong?

[MikeRL411]

It would be easier to go with taller pistons or longer rods.

[bagged_datsun]

if i remember correctly the only way to really weld cast iron is to heat the whole head up to a few hundred degrees and then weld it :o

[ggzilla]

An expert welder can do it no problem. Hobbyist welders generally don't have the know-how.

 

Solution: Replace the 1955-designed 3F engine with newer Japan import engine. Even a small 3 liter six will have more HP than the 3F. Might even be cheaper.

[Guest DatsuNoob]

It would be easier to go with taller pistons or longer rods.

 

Or figure out the clearance of the valve height at TDC, then get the head milled to spec. probably alot cheaper too.

[zed]

thanks for the replies. You guys in the USA have it pretty good with motor prices - a used Japanese import V6 here is very expensive, like maybe $US3000 - because of the import levy to protect the local motor industry.

[datzenmike]

It would be easier to go with taller pistons or longer rods.

 

This will work if the engine already has a minus deck height. In other words if there is room to allow the piston to travel higher without extending out of the block and hitting the head surface.

 

For Nissan engines a positive deck height should not exceed 0.3mm above the block. This would safely fit within the crushed gasket thickness of 1.2mm and still allow room for rod stretch at high RPMs. Both the L16 and later Z22E motors are examples of positive deck heights.

[HRH]

Yeah, my Datsun guru can weld cast iron no problem. You just have to find someone with the experience and confidence to do the job. What is a v912 head? I imagine we didn't get that in the states, but I've never even heard of it associated with an L block.

[Braden]

either have the head shaved, either get flat top or domed pistons, or get the 4f motor, might i ask why you would want to boost your compression on that old straight 6 anyways? it has plenty of torque for offroading and on the highway it handles like a lead sled

[Orange620]

Since you're basically just using the weld to fill an area not repair a break, you could probably use high nickel content rod at a lower temp than using actual cast iron rod, which is what you'd make a repair with. Your welder would know.