One advantage of this engine over a small block is that the intake and coolant necks would be on the right side of the engine. Also, is it possible that the block is aluminum?? Since this car was built to handle well, I'd assume they would want to reduce weight in the rear of the car. 200 hp is not all that impressive but 275 lbs of torque in a car that light would be a blast. I'm also betting that these engines are cheap as dirt at the scrap yards.
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11:16 PM
Jan 18th, 2000
lowCG Member
Posts: 1510 From: seattle,WA U.S.A. Registered: Jun 99
The block in aluminum but the heads and exhaust manifold is cast iron. I wonder how the weight of this motor compairs to the 2.8? If you could get a set of aluminum heads and bump the compression to 10:1 and get a camshaft with a little more lift, I'd bet you coud easily get 250 Hp and raise the torque to well over 300 ft lbs. Now, add a turbo...
Some say that 4.9 has problems somewhere inside the motor (can't remember what). My grandma has one of those caddys with almost 200 thousnad miles on it and it will still put you back in your seat.
It bolts up to the transmission anyway, but that's pretty much the end of the "bolt in" part of the swap. Next you have to figure out motor and dogbone mounts, that'll be some fabrication and lots of time spent there. Cables, coolant hoses, wiring harness, ECM change over, etc...
Still it's an interesting swap. I heard about this last summer from some SCCA racers and we discussed it in a past topic. This would be an awesome swap. Anybody think that engine is underpowered ought to race my Batmobile. With the current worn-out Chevy 350 engine in it, it's only a little over 200 HP and about 300 TQ. BUT, it's so quick, it's scary. Huge amounts of torque is what makes it very quick. Same with the 4.9 Cadillac Allante engine, except it's light and my small block is heavy. Hmmm, an engine with the power of a V8, but weighs the same as a V6, just think about it...more power with no sacrifice to handling. Headers alone would make a noticeable power increase.
Just some added info that I got off the Fiero Racing list (that the owners are a part of)
The engine weights exactly the same as the 2.8 V6. It is (as already posted) a aluminum block with cast iron heads. The owners took a round hunk of steel and carved off everything that wasn't a flywheel to make the custom flywheel to use the Getrag 5 speed. The owners have one of the few GM Motorsports LSD's for the Getrag. They are using some kind of electronic fuel injection in the open mode. They hope to convert to TPI fuel injection or sequencial fuel injection system (this is only the electronics, not the manifold setup, it wouldn't fit the 4.9 engine!)
According to a mechanic buddy, this engine started life in 1981 as the "HT 4100" and was GM's first attempt at an all-electronic engine. At first it was a piece of crap. GM then went from 2-bolt to 4-bolt mains, then went from 4.1 to 4.5 liters, then from 4.5 to 4.9. With every new iteration, the engine got better (typical GM - look at the Buick 3.8 and Chevy 2.8/3.1/3.4).
I'm guessing the problems with the original HT 4100 may be where this motor got its bad rep.
