912 big bore 1880cc upgrade??

[gd2bwise]

Hi...

So anybody have any information about those alluminium 90mm bore kits that dont get hot? thinking of changing the cams to torquer cams with weber 44's and appropriate exhaust?? Any experience here anybody? or should i just go with 86mm 1750cc slip-ons ( no machining) change the cams as above and stick with weber 40's ?? interested to hear of anyones experiences here with this... and the thicker alluminium cylinders etc, its said with the street version setup with the previous outline above(1880cc upgrade) you get great low end and way through tourqe with about 140 hp, very nice in a very light 912!...info anybody

Cheers!

[Jaems]

There is not any longevity history on the 90mm bore kits, yet. Because of the Aluminum expansion and contraction from the heat. It could cause excessive wear on cylinders and rings. To go with this you would need to port and polish the heads. Go with a stronger crank like a forged skat. I doubt that the 1880 cc would give 140 hp. It would depend on what dyno you put it on. Maybe a engine dyno, but not a chassis dyno.

Changing the cam to one that would give more torque would make the car more street-able. I would keep the 40 Webers.

To do it right these engine can and are very expensive to rebuild. It can take up to $12K plus to do it right. Those that claim they did theirs under $5K. They may be rebuilding again in another 25k. If you are looking for a longevity engine then you need to do it right. If you are looking for a barn burner. Then remember if you drive it like a race car then you need to maintain it like a race car.

If you have a lot of disposable income. Then go for the 90mm bore kit and the recommended parts, the CD box, and larger coil. Let us know how much hp it develops on a chassis dyno and how well it holds up over time. I would and I am sure others would be interested in the experiment.

[lane912]

Originally Posted by Jaems

There is not any longevity history on the 90mm bore kits, yet. Because of the Aluminum expansion and contraction from the heat. It could cause excessive wear on cylinders and rings. To go with this you would need to port and polish the heads. Go with a stronger crank like a forged skat. I doubt that the 1880 cc would give 140 hp. It would depend on what dyno you put it on. Maybe a engine dyno, but not a chassis dyno.

Changing the cam to one that would give more torque would make the car more street-able. I would keep the 40 Webers.

To do it right these engine can and are very expensive to rebuild. It can take up to $12K plus to do it right. Those that claim they did theirs under $5K. They may be rebuilding again in another 25k. If you are looking for a longevity engine then you need to do it right. If you are looking for a barn burner. Then remember if you drive it like a race car then you need to maintain it like a race car.

If you have a lot of disposable income. Then go for the 90mm bore kit and the recommended parts, the CD box, and larger coil. Let us know how much hp it develops on a chassis dyno and how well it holds up over time. I would and I am sure others would be interested in the experiment.

i am also thinking of doing the 86mm slip on p&c kit. i would like to know what people think of it