266cu X-FLOW

[xrglen]

starting my new motor soon, a 266cu x-flow, solid cam, etc.
boring a std block to 240 thou then fitting 6 sleeves and boring to 120 thou over standard. this will leave 60" wall thickness in steel, not cast iron.
using std 3.8inch v-6 holden vs clip pistons in acl race series.these have the right deck hight without decking the block.
then using std 200 rods with bushed small ends to holden pin size, shot peen, beam polished and arp bolts. the top of the small end needs to be machined to a slight tapper to fit into the holden piston.
with a bore of 96.5mm the std acl race head gasket will just fit at 96.55mm.
now with a 3.8 bore and a 3.91 stroke i think it should alot better than a std 3.68-3.91..
i saw a 250 get fitted with 3.85 pistons for a speedway motor on methanol last year and it split down the centre after 3 races, but that was over bored too much with 80" cyl wall sleeves, but not much left of the block to hold them.
im taking 3 blocks into the borer first to see which one has the most meat left after the 240" holes are bored.. i think some block filling will be needed..
cheers..

 

[Anonymous]

Hey there mate, I'm in the process of reassembling a similiar motor myself, after a bit of an inspection and a freshen up.

Stats -

Standard Big End Size - 2.123
Offset Ground to - 1.967
Increase in Stroke of - 0.156.

Standard Stroke - 3.91
Add Offest of - 0.156
New Stroke - 4.066

Standard Bore - 3.680
Overbored by - 0.120
Net Bore Size - 3.80.


Bore Size - 3.80
Stroke - 4.066
Cylinders - 6
Cubes - 277 approx.

So, nearly 280 cui. I went this way without sleeving the block; I did however, put about 3 or 4 inches of plaster of paris in the bottom of the water jacket, just in case I believe you could definately get more cubes out of these motors with sleeving and a longer stroke crank.

Some people might say this motor has a horrible rod/stroke ratio, and question the motor's ability to rev. Well, this motor was very strong in my Cortina, and ran up to 7k revs with no problems, or hesitations at all.


Lee.

 

[xrglen]

sounds great, what rods did you use and what size were they?
did you use the V6 pistons aswell? cheers

 

[Anonymous]

sounds great, what rods did you use and what size were they?
did you use the V6 pistons aswell? cheers

I used a Datsun rod, and the v6 commodore pistons, as for size, I cant remember off the top of my head what length they were.

I cc'd the head today, and concluded I was running 11.8:1 Comp. ratio. Might have to look at dropping that down a bit I think