Engine / Turbo configurations on a budget

Both were wrong.

The most common "max" cylinder diameter is 94mm. That would give you

1915cc of displacement with a stock stroke.

You *can* go bigger too, but it gets a little hairy after that, and certainly not a "budget" solution.

Instead of making cylinder diameter bigger, you can increase stroke. You can buy a long stroke crank from a variety of sources. The prices have come down some during the past couple of years. The most common alternatives (and displacement they would offer if used with the abovementioned 94mm cylinder kit) are:

74mm (2052cc, not worth it, small increase and same money buys more) 76mm (2110cc, still not quite worth it, same reasons as above) 78mm (2165cc, this is the first "long stroke" crank worth all teh effort, and parts matching is easy with other stuff) 82mm (2276cc, this is a very good choice, "B" type 94mm pistons are readily available for just this stroke, so building the engine is easier) 84mm (2332cc, not bad, not bad.... quite common too, requires a lot of case clearancing and most likely the camn needs to be notched too to allow room for crank/rod to swing past it) 90mm (definitely not for a beginner, I've only heard of these and they require a ton of clearancing. Better get an aftermarket case that has more room for clearancing in the casting. "Budget solution" was thrown out teh wiondow long before I wrote the size. lol.)

So choose your basic hardware, study the solutions and other people's experiences (I would recommend a month or two of surfing at

and in their forced induction and high performance discussion forums for more info before you start)

-And slap a Turbo and an intercooler on a 84x94 :) You'll have hard time finding anything out on the road able to keep up. Assuming you don't blow your transmission, or lose traction.

There are numerous 300-400hp bugs out there on the road, daily drivers or weekend warriors. And in a car that weighs half of any typical "sportscar" out there. Power to weight ratio works in your favor here. :)

TO3 and it's countless variations have been very popular too. 03/04 hybrids as well.

if you don't want to open the case up for larger cylinders... well.. in my opinion you should abandon the project altogether and save money until you can do it right :)

But to answer that question, your largest technically possible cylinder size is 88mm. With a stock 69mm stroke, that gives you 1679cc. And VERY thin cylinder walls that WILL cause you trouble down the road, even WITHOUT turbo. Add boost, and they crack open like a can of sardines. :-D

A safer "big bore" size would be 87mm, bringing the displacement to a whopping 1641 from the stock 1585cc.

Whether the marginal increase is of any use, is arguable. At least if you bought these new, you'd get more power because the pistons, rings and cylinders would be NEW and tight. So... staying reasonably safe and reliable, your choices are limited to stock 85.5mm or 87mm big bore. If you don't want to have the case opened up. (why that limitation anyway? price? Then you can't afford to do much of anything, knowing how much more there is to high perf engine building.. that's a miniscule cost in the big picture)

I think it might be doable. A normally aspirated 1600cc gets expensive and difficult to build after something like 80hp, but I have built them up to 130-140hp and know several that make 150hp. NOT CHEAP, and these are all-out race engines :D So from the size point of view, it's possible. The turbo would make it produce 130 easier and at lower rpms.

Go to shoptalkforums and use the search. WEEKS of reading to be found on the subject. Turbo engine building has not been covered too much here.

Jan

"Mac

Hear hear :)

Damn, how could I forget. Give lowbugget a call, they know just about all there is to know about 1600 turbo.

Jan