Doing some stupid shit to an old datsun head

[snelens]

The chamber design will be the secret squirrel stuff, but I'll post it up anyway, along with an explanation of how/why it works.
I've drawn from the knowledge of others on many occasions, you can't learn all this stuff on your own, there is far more than a lifetimes knowledge to obtain - may as well pass on what I can.

Very, very impressed with this attitude. Well done, man.

Feel like doing an alloy head to suit a pinto? Head came from Esslinger and has had a botch job of porting. I think it is like this one;

[Gassed250]

Very, very impressed with this attitude. Well done, man.

Feel like doing an alloy head to suit a pinto? Head came from Esslinger and has had a botch job of porting. I think it is like this one;

That's a 2.3 head

[TK]

Onwards!

Belted the guides in, they'll have to come out again for porting, but they have to be in for seat inserts & seat cutting.
Reamed them to size in the seat & guide machine & then on to fitting the seat inserts.

Machining insert recess's for the intake seats:





De-burr the holes & belt them in with some never-sieze so they don't gall on the way in - .007" interference fit:



Repeat process for exhausts:





These are tool steel seat inserts - pretty tough, they'll hold a good seat for quite a while.

[TK]

I've dug up some ecotech V6 valves that are 8mm stem & slightly larger than the valves I'll be using in this, I just turned them down to the right size in the lathe & bingo I've got some dummy valves for cutting the seats etc.

Time for lunch, then seat cutting, then clean up the spark plug holes, then out with the grinder.

[chartreusehj]

Could you explain in simple terms re the head offset and the reasoning behind it?

The flow through the open valve WILL change if the discharge through it is impeded by the bore wall.

ie: Move the intake valve further away from the bore wall= room for bigger intake valve/better flow/more valve lift before valve hits block.

[Dogsballs]

nice work. interesting on the peening with the hammer, very very cool idea to help settle things

[TK]

You can actually measure the hardness gain after peening, it's quite substantial, taking the weld from barely good enough to hold a gasket to just below std head casting hardness.
If it's not done there can be problems!

[GSRman]

Wow

[Mighty Mouse]

jeasus man you don't fuck around.
looks like it'll be completed by 4:21pm at this rate.

[dat2kman]

I unshroud valves and notch out tops of bores. 50mm inlets, in a Datsun head.

[9triton]

Onwards!

De-burr the holes & belt them in with some never-sieze so they don't gall on the way in - .007" interference fit:

These are tool steel seat inserts - pretty tough, they'll hold a good seat for quite a while.

done with head and seat at room temp ? or chilled seats ?

[TK]

Yup, room temp, on some heads it's best to warm the head up (like x-flow coons & TB42 Nissan), but the datto's are fine.

Feel like doing an alloy head to suit a pinto? Head came from Esslinger and has had a botch job of porting. I think it is like this one;

Yeah, why not! - hope you're not in a hurry tho!

I unshroud valves and notch out tops of bores. 50mm inlets, in a Datsun head.

Not in an L you don't!

Cutting seats, as there is nothing left of the original chamber there is no datum to base seat height on, so I measured another head, figured in the difference in thickness of the heads (how much had been milled of the other one) & used that measurement as seat depth.

Intake seats cut to height:



Exhausts cut:





Throat cuts done:





That's all I can do on the seat machine, no room for a top cut, I'll have to do the top cut by hand with a grinder (yay).
Out of the machine, bump intake guides down out the way for porting (exhausts are just going to get ground flush with the port roof), run a tap through the plug holes & on to the porting station:

[260BC]

Errr, with a diesel you don't need spark plugs

[TK]

1st chamber done, haven't CC'd it yet.
I'll just post pics & let the cleverer guys comment for now, gotta bugger off in a tick:

[cracka]