balancer for supercharger

[balldrick]

Gday guys,
Currently adapting a eaton M90 to my 250 and i was thinking I would have to have a custom serpintine pulley made to bolt to my balancer. Then i noticed a EL balancer is a 6 rib serpintine. As far as i know the bore diam. =1.2500 and the seal diam. 1.7500 is the same. Do you think it'll fit .

 

[73GreenMachine]

I believe it will as I have an EF balancer on mine. If they are the same (as I imagine they could be) that should be fine. On a sidenote I am thinking about putting on an M90 as well in the future, where do you plan to mount it? My current thought is to low mount it around where the alternator is. Are you going to source the supercharger from a Commodore V6?

 

[balldrick]

Thanks for the reply mate, Im currently making the mounts to locate the charger on the pasenger side on its side in between engine and shock tower with snout at the bottom. You need a snout extention that runs it under the dissy cap(i have a DUI 11 which is taller) relocate feul pump,remote oil filter. My M90 is of a thunderbird i think but seems you could do the same with holden one. My biggest problem so far was tracking down the snout extention capa say they have them but dont,magnacharger havent got back to me in two weeks so im going to see somone now about the yellaterra two piece snout extention, they have a kit with gear cover and a short extension but i need there longest one (245mm).So ill see if they'll sell me gear cover and 245 ex. Ill still need to machine up a snout pulley to ofset it a bit more to line up pulleys you need about 300mm from were the gear cover bolts to supercharger to the pulley. I have fabricated my own inlet and outlet manifolds and running it through a barrell water-air intercooler to Barry Grant demon blowthrough carb, Classic Inline 4 barrell manifold and Alloy head.

I just read how you can fit a EF crank ( machine back of block to take EF seal) 200 (3.3) rods and Chevy 305 pistons (3.766). Does anyone know if this works in the pre-crossflow 250.

As i get further along ill try and post some pics.

 

[gb500]

re chev 305 pistons -you'd need to check on the deck heights and piston heights -

the aust late precrossflow 200 rods are longer than the 250 rods - so to use with a 250 stroke crank you need to have lower piston height pistons - which the special 200 rod ACL race series pistons are : 1.136" piston height

http://www.aclperformance.com.au/6MKRY9412.htm


std aust 250 pistons are 1.52 " piston height
aust late precrossflow 200 rods are 6.27 "
aust precrossflow 250 rods are 5.88"

deck(block) height for late 200 and 250 precrossflows are approx 9.4"


No idea what the 305chev piston heights are - some maths to make sure you dont pop them out the block is in order.

i may of mixed up precrosflow and crossflow pistons here - but i think they all work
brett
melb

 

[balldrick]

Thanks Brett,
I spent all day looking for different piston combos and found,
Nissan 3.5L V6
3.760inch/95.50 bore
compression dist-1.174inch

I measured my bores and it seems to be 3.73inch(i think it was board out 60 thou ).now i need to find piston pin diameter. Do you think these would work on the 200 rods?

 

[gb500]

250 crank = 3.910 " stroke
200 rods = 6.27'
v6 piostons = 1.174' piston height

3.910/2+ 6.27+1.174 = 9.399"

i said before that block height is approx 9.4" (maybe 9.45'?)- need to measure

theretically should work

BUT i would be worried about block wall thickness with another 30 thou out of the walls = 80thou overbore.(3.760 - 3.680= 0.080")-

look what happened to 10sec falcons block when turboed

and other thing is do work out how the pins are held in - circlips - or pressfit(as per ford) -all changeable - but may require machining/bushing of conrod eye .

acl=ready made pistons- But only to 40 thou?

 

[balldrick]

I see,
I have two blocks unfortunately both 60thou over is there a way to check them to see if i can go to 80 thou, as i dont think you can get the ACL pistons any more. As for the pins what do you think would be better circlip or press fit? Picked up a EF falcon 12 counter weight crank today all looks the same exept for rear seal which is 3mm bigger. I think a little machining to go straight in.

Thanks for the help Brett.

Does anyone have or know were i can get some 200 rods?

 

[gb500]

a reputable eng builder can sonic check the bores for wall thickness - not sure what the min thickness would be ( 120thou?- need to check).

are you sure you cant find a 250 engine about and start with that block - maybe reuse your psitons?

one other thing - what comp ratio will you be running? - if supercharged - wont want to be that high - and the ACL'spistons etc will give you approx 10.5. as made for NA motors.


something to consider before forking out .

the ACl's listed i am sure you can still get ( $800?)