big bore rebuild

[EDDIE71SB]

Hello everyone, I have questions regarding a rebuild for a 1.7 L block; maybe you guys can point me in the right direccion.
I'd like to rebuild my 1.7L with 96mm P & C's. Would that be too large a bore increase ? Would there be enough material left over between the O.D. of the cylinders and the head studs, where this is safe ?? Do case savers need to be installed ??
As far as the stroke is concerned, I'd like to increase it as much as possible without having to clearence the block (trying to keep the internal structure intact).
Therefore, I'd like a combination of 96mm x 76mm. Would this be possible ??? Do I need special stroker pistons and rods ??
This wil be a daily driver. I have dual Webber 40's & plan on a mild Norris cam. Will this last ??
Thanks for taking the time to read this; advice would be appreciated.

[iustasail]

I did a 96mm BB on a 1.7L. You will have to get the heads fly cut to fit the larger cylinders(some say 1.8 heads work without having to be cut)mine were stock 1.7's. I used toothpaste and lapped the cylinders into the heads and did not use head gaskets and most people say they cause head leaking vs stopping it. Mine came out well and did not leak. The stock crank is 66mm and you will have to do a good bit of case clearing to use a 76mm stroker and have all kinds of problems with the big bore kit as it is made for the stock 66mm stroke.

[red-beard]

I have a 71 1.7 and it is leaking oil and winter is here. I'm looking at rebuilding (Since I'm going to be fixing the leaks anyway) and I was looking at the "Big Bore" kit for the 1.7. It looks like an increase of only about 10%. I have planned to go to an aftermarket fuel control anyway. How much power increase do you think you see ?

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[efeinsmith]

One issue that should be considered when doing a 1.7 big bore upgrade and remaining with stock 1.7 heads is that the sealing surface for the cylinder/head is pretty thin. A better approach is to use a 1.8 kit and have the 1.7 heads flycut for the increased outer cylinder diameter (the case end is the same). This will give you almost twice the cylinder thickness at the head end.

[Patrick]

As far as I know, the 1.7 96mm piston kits are no longer available. Your only choice is to buy the 1.8 or 2.0 kit and have the heads fly cut.

If anyone is interested, I have a pair of 1.7 heads for sale that have been rebuilt for the conversion. They have all new guides, new exhaust valves and are fly cut for the 1.8 96mm p/c's. I never built the engine and they have never been run - $150 for the pair.