Buzz's Engine Makeover

[TopNotch]

Well, now that I'm laid up recovering from a heart attack, I have time to write this...
You may recall from this thread that I had acquired a later model cylinder head that I was going to use on my duke rebuild. As it says in that thread, my research showed that the head was a 91-93 VIN A head, and I thought it would fit on my 88 duke block. Well, as it turned out, two of the bolt holes didn't match up. So in true "make it work" fashion, I modified the head as shown in these pictures:

I filled in the old hole with a mild steel rod, and drilled a new hole. The rod is held in with JB Weld. With nearly 1000 miles on the engine since getting it back together, and no problems, I think it worked. Here's the other hole I fixed:


I wanted to use Big Block Chevy roller rockers on the head, so I had to drill and tap the rocker stud holes as shown in these pictures. (The head in the pictures is my old one, which had a crack, but it was good practice.)



Actually, drilling and tapping for the bigger studs was easy. But enlarging the holes in the guide plates was hard -- they are made of extremely hard steel.
The roller rockers I used were some stainless steel ones I found on Ebay. Below is what they look like on the engine. BTW, the pushrods I used for this combination are Melling MPR-389. They are for a late 60's - early 70's Ford V8.


The head was not the only mod I did to the engine. I put in an Accelerated Motion camshaft with a little more lift and duration than stock, and an all metal timing gear set:


I also put on a later model starter to save weight. This picture compares it to the original.

BTW, the new starter works just fine.

Below is the engine back on the cradle, with re-assembly almost finished.

Before I put it in the car, I put in oil, put in the pressure sender, and cranked it over with a battery. A meter on the sender showed I had oil pressure.

Back in the car...

The finished product...


So, you may be asking, "How does it run?" Well, it runs fine, but I'm not sure how much better. Before the rebuild, it would start to run out of "oomph" at 4500 RPM. Now it feels like it has more to go, but I'm afraid to run it up higher. Maybe after I have a few thousand miles on it.

[Roger]

Sweet!
Very nice indeed!

I'd call it a 'FrankenPat' engine.

What did you do with the bore and stroke (if anything)?
Did you use the stock type oil pump?
Any ignition mods?

Inquiring minds want to know.

[TopNotch]

I had the block bored .040 over, so the engine is a 154 instead of a 151, and had the crank ground. No mods to the ignition or oil pump, but the oil pressure is very good, even at slowest idle.
And BTW, if anyone is curious about the valve cover, see this thread.

[TopNotch]

Yesterday I ran my rebuilt duke briefly up to 5000 RPM. It felt like it still had more to go. Before the rebuild, it used to begin running out of "oomph" at 4500 RPM. 5000 RPM is scarey territory on a duke, but it ran nice and smooth.

[oldone]

pat thats a nice piece of work, but i still don't know how you know all this stuff ( rods out of a 70's 80's ford?) . are you back to work or taking it easy for a little while? nothing like rebuilding a motor to ease you back into the work place.

[TopNotch]

I figured out how long my push rods had to be, and I found a chart online from the Melling company listing all the push rods they make. I found the ones that were the length I needed, and then looked up in another Melling document to see what they originally went to.
Edit: I rebuilt the engine before the heart attack. I just wrote about it afterwards. But driving it is good therapy.

[oldone]

is it back to a daily driver yet?

[TopNotch]

I started to work again Monday, and am driving it every day. I drove it to work before the heart attack also. It's the only Fiero I have right now with working AC, so it's the best one to drive on warm days.

[aerodonamic]

Pat I just read your thread on Buzz  to see what all the buzz wuzz !!! I really liked the look and sound of your car at Sat's meeting nice work!!! By the way where did you get that starter   Do you know if it will fit the V-6 engine?? PM me when you get the time thanks Don. H.

[TopNotch]

Yes the starter will work on a V6. The 4 and 6 starters are the same.
It is the starter for a 1998 through 2000 Pontiac Grand Am, among several other GM cars.
I had to shim it quite a bit to make it mesh properly on my car. It needed shimming in, so only at the outer bolt. I used washers instead of standard shim pieces.

[GTRS Fiero]

Is this essentially a streetable version of the SD4?

[TopNotch]

Is this essentially a streetable version of the SD4?

Not even close. A stock 88 duke is rated at 98 HP, and I get maybe 120 out of this thing. But a SD4 can easily put out 300 HP.
But in any case, I call this a XD4 (extra duty 4). And it now has over 38,000 miles since the rebuild, so at least I didn't break it.

[GTRS Fiero]

Have you run the higher RPMs, now that it's broken in?  What is the displacement?

My understanding is that the SD4s were not streetable, for both emissions/certification and reliability issues.

[Raydar]

...
My understanding is that the SD4s were not streetable, for both emissions/certification and reliability issues.

I had a (fairly mild) SD4 for a while. It was loud and it was thirsty, but I think if I had ever gotten it tuned correctly, before I sold it, it would have been quite streetable.
It was the rest of the car that made it not practical. Had a leaky Automoda convertible top, and really crappy brakes.

[Raydar]

Dragging this up from the depths...
Pat, did they send you the specs for your cam?
I have run across an engine (a Duke) that's been rebuilt and ported, and had a reground cam installed, and I'm trying to decide if its worth my trouble or not.

Did you rebuild your force balancer? Or did you just buy one of Rodney's units?