Following earlier posts have decided to go ahead and rebuild the engine for the 110
Its a 3.5 on twin SU's runs mostly on lpg and is used off road a lot.
More or less convinced that will take the opportunity to raise the compression ratio probably to 9.7:1, the question is what to do about the cam. Refit standard 3.5, use standard 3.9 efi or and RP4?
Views?
Gerald
On or around 18 Nov 2006 01:53:22 -0800, "idris" enlightened us thusly:
3.9i one is reckoned to be a good bet, although it's almost identical to one of the 3.5 ones - same profile and timed 2 degrees different, IIRC.Badger can no doubt supply details...
Either fit the 3.5 cam (ETC6850 or ERC2003, NOT ETC 6849) or the 3.9 EFI cam (ERR5924) and use BAK needles with std filters or BBW needles with cone-type filters (K&N, Pipercross etc). If you use 9.75:1 vitesse pistons and composite gaskets and skim the heads by 30thou, you will end up with about 9.6:1 cr, or fit 10.5:1 P6 pistons with composites and a 20thou skim and get 10.2:1. Both cr's will be ok with unleaded. Fit a stud kit instead of the std main bearing bolts and torque the nuts on the studs to 80lbft. Badger.
Thanks Badger, having seen your comments on other similar previous threads was hoping you would respond. With you on the cam, the needles and the stud kit including the reasins for it. The pistons I have in mind are from RPI and are described as 9.75-1 +20 compression + 20 piston so assume these will suit a + 20 rebore and will not need to skim the head. Dont have sugfficient knowledge of head gaskets to understand your comment re "composite". Gerald
Composite head gaskets are thicker than the original "tin shim" type, but they seal considerably better and do not allow blow-by into the valley area in the way that the tin ones do. They are called composite because of the way they are manufactured, basically a heat and pressure resilient material sandwiched either side of a metal core piece, with added "fire-rings" to seal the combustion gasses. They are superior in ALL respects to the original tin versions, but really need the heads skimming by the difference in thickness (30 thou, ish) to maintain inlet manifold alignment and compression ratio. Badger.
Thanks, understand now. Gerald
Thanks, understand now. Gerald
On reflection 30 thou seems like a hell of a lot!
Gerald
Not really, it's the difference (actually slightly less!) in compressed thickness between the shim or composite gasket. Bager.
Ok, thanks
Gerald
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