A 4.3L Performance Engine Build by Pieces


All along, I've had the idea of a "Phase II" high performance engine for the custom sports car I'm building. All it's major components come from a 1994 Mustang donor including the 3.8L V6, T5, 7.5" rear axle, front spindles, brakes, and many other components including the ECU and wiring harnesses. I jokingly refer to it as my "Honey I Shrunk the Mustang" project. However, it's more fun to think of it as a re-purposed '94 Mustang where only 3 criteria matter: 1) keep your butt cheeks off the asphalt; 2) go as fast as you can; and 3) have as much fun as you can. The car in the photo below is NOT my build, but it has been a major inspiration for me, and mine will look similar to it, but will have a windshield.
Cool Red & Alum 2.jpg

My build isn't finished yet. It's only partially built, but I hope to have it largely completed by the end of 2017. Here are some shots of it.


Upon disassembling my donor, I found the 3.8 was actually a '97 with the '94 intake and accessories mounted to it, i.e., a later replacement engine. That's a good thing. However, to get the car registered I'll need it to stay stock and use the stock ECU, etc. Once it's on the road, I can change things, but not now.

Along the way, I picked up a 2000 3.8L with a somewhat checkered past, but complete. I had only planned to put the dual port heads and intake on my '97 engine, so I wasn't worried about it.
2000 Dual Port.jpg

As I've continued to follow along here at V6Mustang.com, my interests and ambitions have grown. I've set my sights on a 4.3L build with 275-300 HP. Recently, I bought some used performance components from another member here. I've located a good, competent engine builder in my area with some 3.8L experience and an excellent in-house machine shop. I'm still gathering essential pieces, but I'm on my way. This thread will be used to document my progress in achieving that goal.


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Here are my new (used) goodies as of today.

6 x 3.8450" Wiseco pistons on Eagle rods. One piston needs replacing.

A '97 F150, 4.2L crank with windage tray.

Ported and polished heads with oversize valves and aftermarket beehive springs. They have a few thousand miles on them now though, and they're not this shiny now.

I still need a suitable zero balance flywheel (preferably one lighter than stock) and a zero balance front harmonic balancer, new piston rings, the right oil pan and dipstick, a high capacity oil pump, and performance camshaft, lifters and pushrods to have an essentially complete long block setup. So, I'm still in the "looking and gathering" phase of this build.



Active Member
Thats cool i bought his turbo kit its been in a box on my bedroom floor for almost a year lol id be working on the stang now but the power is out at my shop :cry:


More pieces!

Part of what I purchased a while back were two camshafts & some hardened push rods. They arrived a couple of days ago. It turned out one on the cams is just about an ideal grind for my application - at least from the off-the-shelf, non-custom set of grinds in the marketplace. It turned out to be a Comp Cam's 265HR-115, which they characterize as "a serious street cam."
With a range of 1,500-6,000 RPM as it effective performance area, that's pretty darn good for me.

The cylinder heads have a suitable set of valve springs. Included with the cams was a set of push rods by another vendor. These were Trick Flow 7.100 .080 pushrods, which gives most of their major dimensions away. They are approximately 7-3/32" or ~7.094" long, 0.080 wall, and 5/16" diameter. My calipers are 6" ones, so I had to use an accurate engineer's rule to measure the rods. I may be off a little. They could be 7.100" long as claimed on the product. Comp Cams recommends a their own set of chrome-moly pushrods of 7.150" long. 0.080 wall and 5/16" diameter. So the only variance is ~ 7.150" - 7.094" = 0.056" maximum shorter than recommended. I'm not enough of an engine guy to know whether that is workable or unacceptable. I hope the engine builder will know as they're in nice shape and would save me about $125. I'll see if Comp Cams Tech folks will respond to that question too.

The second cam has some pits on the bearing surfaces plus some small pits on a few lobes. They're shallow enough that maybe they could be polished out, but I don't think it would be acceptable to use it in a rebuilt engine. I don't plan to use it. However, I am curious about what grind it is and who the manufacturer is. I turned up nothing so far with my Google searches. Do you recognize it?
Here is a right-side-up image of the bottom numbers in the photo just above.

Here's what the cam looks like.
Maybe I can use it in a metal sculpture or something? If you think you know what/whose cam it is let me know. I am curious.



Yes, they are custom ones. I have a copy of the specifications, but they were done for a turbo engine. I'll be getting a new set with less dish and a higher compression ratio.


No, I'm really just getting in. My 4.3L build will be my first non-stock 3.8L V6. Ive had 3 stock ones now in various vehicles.