Hey guys.... I posted the following in the "Tech" forum and was told to ask about it in this "FI" forum, specificly for the the question about manipulating compression with head gaskets. A

Any advice you have for me on the whole thread would be appriciated too.

Thanks!!

Ok, here is what I am planning on doing provided I don't run short on funds:

I am buying a GSR Engine Swap, but before I swap it into my '99 Interga LS, I'm planning on striping down the block, sending it out to Golden Eagle to get resleeved and bored our to about 84mm. Getting new Pistons and Rods (not sure on the compression yet). And getting Skunk2 Stage2 cams and new valve springs and retainers.

My two questions are:

1. I am planning on turboing this engine down the road (but probably not for a couple years), so I don't want too high of a compression ratio. But I don't want to sacrafic too much power between now and the time I finally do turbo it, so I don't want too low of a compresstion now. I have heard of people talking about getting mild compression pistons (like keeping the normal LS compression) and just using a thinner head gasket for now to raise the compression. And When I'm ready to turbo, use a thicker head gasket to lower the compression. What do you guys think of this approach? What kind of compression numbers, defferences, would thinner and thicker head gaskets give me if I were to use a given mild compression piston?? I'm sure these won't give me extream changines in compression, but I'm just looking for ball park. I would be happy if this approch would give me about 10:1 (or even a little higher), and then about 9:1 (or even a little lower) when I turbo it.

2. What type of effect will the larger displacement and more aggresive cams have on my fuel system? And my Air/Fuel ratio?? Will I NEED to upgrade it? If so, what will I need too do? I'm only asking because, by the time I do all of this, I will be our of cash for now, and doubt I will be able to afford upgrading my fuel system right away. I plan on it in the future, but will I NEED to now? (And also, what do you recommend me getting now that will be useful with my tubro, so that I do not have to upgrade the same part again when I turbo)

I am opened to any suggestions. And any advice on this mod project would be greatly appriciated!

Thanks for your help!!

 

I think I'd just build something that has compression that is ok in either scenario. 9.5:1 should still be very decent while the car is NA and will be a pretty good FI compression ratio as well.

Aside from the hassle associated with switching gaskets, you need to get cam gears to offset the change to the cam timing by increasing/decreasing the distance between the cams to the crank.

Sonny

 

Ok, thanks for the advice....

Anyone else have any thoughts or advice?