Real Fiero Tech

It very well may be a different casting, from my understanding of the evolution of the SD4 head casting, It was: 10027776/10027775 1st Run Iron head, with Production based exhaust runner shape, and large pushrod pass through holes (must be sleeved and ported) 10031322/10031323 Redesigned Iron head w...

There is a 437 head on eBay for $1500 (I think that's a bit high) s-l1600 (15).jpg The chambers are interesting, they have a lot of work done to them. They must have been welded to achieve the heart shape. No other SD4 head I have seen has that much material in the chamber, they all have a sort of b...

After reading the later version of the SD4 build book, I discovered there are 2 versions of the Fel Pro sd4 head gasket. Pontiacs description differs from Fel Pro's and the interchange was goofy, but the aluminum head has a different fire ring arrangement to eliminate brinelling. 1015 has a steel fi...

Found this dry sump pan on eBay for a "Pontiac 2.5l V6" $30, has some damage. Bought a brand new duke pan on Amazon for $70, hopefully after some careful grafting I will have a better dry sump pan. The pump I had bought years ago was actually a power-steering pump, so I found a different o...

I found a cheap harmonic damper on rock auto. This one is from a chevy straight six. Two v belts spaced 1/4 apart.

Flow of iron head with 2bbl Edelbrock intake.

Did some playing around.
The dry sump pans need modification, no room for a starter.

I pulled the pan out off my storage shelf.
I will need to Fab up a windage screen since it never came with that component

I think these were really only intended for sanctioned racing, which is always a lot of work and expense. And at the time all this stuff was a catalog PN, and easy to order, but racers have moved on from the tractor technology of the Duke.

I may have found the right rockers for use on the duke heads, if the information is all true through the 801 head. It been confirmed, mostly, up to the aluminum 437 head. Most manufactures have dropped the Duke from their catalogs, but BBC roller rockers have been used on the duke heads. 1.606 is th...

OId Camshaft, I emailed Lunati for information. I assume the name means cam is a 295 Duration @ 522 peak lift. cam.jpg I would like a cam that goes to at least .600 lift, hard to find flat tappet cams that high, but Isky offers one. Solid roller is a huge jump up in lift and duration. The oil pump i...

Pistons where pounded out of the block Sunday afternoon.

Nice rods, but the pan is on the sludgy side. Looks like the oil pickup is welded? Was the bracket modified to make up for the extra thickness of the main cap toppers? Going to have the block tanked? I've read that Ross pistons tend to have stiff skirts that beat the cylinders up and oval the botto...

I pulled the pan off last night.

1. Lots of crud.
2. I have never seen journal braces like these
3. No obvious signs of stress, cam journals look a little rough, but not ruined.

I suspect based on the deposits in the cooling jacket, someone ran BARs leak in the coolant.

Your "spare" might be in better condition than mine, ill have to pull it apart and see the insides this week, I had originally planned on running a spec stage 2 unit, but 4 cylinder flywheels are all gone except used these days.

I pulled the shortblock from the car tonight.

I was always wondering what kind of clutch was used. What a nice surprise.

The 4-2-1 header looks salvageable mostly surface rust. but I think the primaries will be to small for the 801 head.

Those are really slick.
I like it.

I reflowed the test today. I plugged the EGR port to see if it lowers exhaust flow. No effective change. I redid the intake, but changed how I mounted the dial indicator over to a mag base, because I did notice deflection, I should reprint those parts with CF nylon to see if that helps, but It did a...

I think the flow stalls after .500 lift because the short side radius is very abrupt. I also think some work on the valve seat may help, it has a simple 45 degree seat and valve currently.

Iron Head flow numbers.
Ran on a SF-750 @ 28" H2O
New graph Below.