221

[lyonsy]

hey
iam after some info on 221 engines as how strong they are etc and the stroke and bore diemession.
do they have the same block as a 250 but just not as tall?
how strong are the cranks?
iam looking into this to see if its viable to rebuild a 221 instead of stroke a 200 xflow or destroke a 250 to a square engine not over square or under square with offset grinding.
i also want to buy a twin cam head for ether way i go and with that should be able to spin to 9000rpm with the twin cam heads from aaap.
mark

 

[aussie7mains]

Get yourself a Nissan rb25dett
forget any ford six, too much work to get anywhere near that level of perfromance.
FYI
221 is 3.68bore x 3.46 stroke with 5.155 rods, (all in inches sorry)
the cranks are iron but plenty tough, the block is much like all pre crossflow but a lower height than the 200/250 XY block.
The crossflow or OHC heads wont fit without a lot of work, nor the twin cam head.
A7m

 

[lyonsy]

hey
iam more looking at it like a project and something i can learn on.
but i reacived some good new today in that a 221 crank can be put into a 200/250 block.
and hey a jap engine will most likely go in bfore this is finshed being built anyway jsut something you put in and every time you drive it you know its something special.
mark

 

[aussie7mains]

221 crank will fit BUT not easily, main bearing journals are smaller on the 221 , and crank flange is different.
Why bother just get a 3.2 litre OHC six or if you cant find one, drop a crossflow 200 crank and rods in a 3.9 or preferably a 4 litre.
this will give you a short stroke six with OHC and with the right head cam etc combination should go fairly well.
take a leaf out of Errol Quarter maine, he runs 8.1 @ 166 with a 191 ci turbo crossflow six in a HB torana, revs to 7500rpm.
i figure hes using 3.9 litre pistons with 200 crank in crossflow block.
a7M

 

[lyonsy]

hey
hmmm yeah custom steel crank looking way to go now then but can get it in what ever size i want
yeah i thought about just a 200 but i rally wana have a play with a square 6 in fairly decent capacity
mark