I have a 205 block off a pinto efi. I would like to build a 2wd cosworth engine from it, running standard or stage1 spec.

what i would like to know first is:
1) do the oil/water ways need to be modified?
2)will the bore need changing?
3)anything else i need to do to make this block usable as a cosworth engine.

thanks in advance

 

nothing needs changing on the block itself. you do know that the crankshaft, con rods and pistons are cosworth yb specific though? and the oil pump and spray bar, and sump.

 

ah good, thanks.

yeah, i know the internals need changing, i was refering to the bare block.
so standard size pistons and rings would work fine without any work needing to be done to the bore? (i know this is on the basis that the chamber walls aren't damaged so to simplify things we'll asume they arent)

what i want to do is get the block ready to have everything bolted to it. then its shopping time

 

you might want to check the piston to block clearance, because of standart classes. ford standart classes 1-4 are 90.800mm to 90.840mm. cosworth blocks are only standart classes 2 and 3. (standart class 2=90,810-90,820 mm and standart class 3=90,820-90,830 mm).

when you have Efi pinto block, you might have there different standart classes, if the block is standard size bore block. otherwise the bore size is same in cossie block and regular pinto block.

maybe you knew this, but just in case for information.

 

no i wasnt aware of this. it is an efi block. im guessing i should check this clearance with the pistons the block originaly had? problem is... its a bare block ive got

 

the bore grading stamps are where the distributer hole is !!!!!

also check the the i/d of the mains on the block i.e bolt and torque main caps down and measure, as some of the efi blocks have oversize mains and you will need suitable bearings

Pugo

 

its basicly no broplem.
heres a pic, where you can find bore sizes marked on the block.

but i strongly recommend that you measure what that bore size really is now, because the block isnt new. you should use dial gauge type tool foor that. whit it you can check if it is cone or oval shaped over tolerances. if you dont have that kind of tool, you might want to ask your local engine workshops (who builds or rebuilds engines).

here are some more spesific info about those standard bore sizes.

standard size bores:
1= 90.800 to 90.810mm (not used in Cosworth engines)
2= 90.810 to 90.820mm (same as in Cosworth engines)
3= 90.820 to 90.830mm (same as in Cosworth engines)
4= 90.830 to 90.240mm (not used in Cosworth engines)

standard piston size:
1= 90.765 to 90.775mm (not used in Cosworth engines)
2= 90.775 to 90.785mm (Cosworth 90.758 to 90.772)
3= 90.785 to 90.795mm (Cosworth 90.768 to 90.782)
4= 90.795 to 90.805mm (not used in Cosworth engines)

Cosworth bore to piston clearance:
0.038-0.062mm

All measures are in millimeters. im not sure what units you use, but its easy to convert them whit this wery useful program. and its free.

hope this is usefull for you.

 

Hectori,

 

ok thank you for your help and info.

 

no problem. happy to help.

 

if any dought i have a 205 cossie block with .5 over size pistons,that i might sell to a fellow jock

cheeRS stu