Join Date: Nov 2001
Thanked 5 Times in 5 Posts
Re: 2.5L stroker kits and cams etc
The V-8 is probably a much more cost effective way of getting more horsepower. There just isn't that much aftermarket support for most 4 bangers.
Now, with that said, there is a lot you can do assuming this is a hypothetical question or you are racing in a 4-cylinder class and want to win.
Any engine can be stroked, it just gets expensive. A cheap method to gain a little stroke is to have the crankshaft reground off center. If you can find .050 under rod bearings, you can have the journals ground .025 off center and gain .050" of stroke and increase the compression ratio at the same time.
You could bore it out .060 is usually no problem. If we are not concerned about reliability, you can go a lot further than that but you may have to find oversized pistons from a different engine.
You can port and polish, balance and blueprint everything and run at a higher RPM which will give you more horsepower. With forged crank, proper rods, double valve springs, roller lifters, etc., you could get up to around a 10,000 rpm redline. If you've got lots of money, we could custom fab an overhead cam setup.
If we are not limited to the present engine and have no budget limitations, the possibilities really open up. With enough machine work, any V-8 could be transformed into a 4 banger. Pontiac did it with the 389 for the Tempest back in the early '60s by just deleting one bank. Other than capping off the missing portion of the block, the only other big problem is the intake manifold. Theoretically, you could go the other way and cut the four cylinders out of the middle, weld the front two back to the back two and build a V-4.
As you said, superchargers are expensive, but turbochargers are reasonable.
Forget the hemi, it's highly overrated. Just because it did great on the drag strip back in the '60s with a blower, don't mean it'll perform naturally aspirated. The hemi does alright but there are better places to start if you are not going to supercharge it. Of course, you do get the testosterone flowing bragging rights with the hemi.
Still, there's no substitute for cubic inches.