Has any body tried doing this?? The rod ength on the f20b is 5.7 while the f20c length is 6.02. So with the f20b stroke of 88m and a rod length of 6.02in gives me a rod ratio of 1.73 which is pretty good. I want to build it to rev to 11k rpms. All I would need would be custom pistoms to stay within the deck height and compression ratio. Or I can have my head dished. Which will allow me to run the length of rod I want with the least amount of side load on the piston skirt.Thats what I hope at least. Motor will be sleeved to 87mm and im planning on running about 25 psi of boost.

 

11000 rpm and 25psi of boost dont usuially work well together. And that is going to be an extremly tight tolerance motor, which means that if you float a valve, or your springs are too weak, or the rockers skip on the cam, say goodnight to your motor, and say hello to a very expensive paper weight.

 

Actually it wont be too tight at all.My compression ration ill be runnin is 9:1. The head will be built ferrea valves,manley dual valve springs and titanium retainers with titanium locks.Custom made crower turbo cams.I think 11k is possible with the right planning in the build and a good tune. And I should still be within the factory deck height with some cutom pistons from race engineering.

 

good luck man 11k is alot....even for the f20b but more props to you if you can do it

 

only thing I would say is do your math because just off the top of my head, I'm thinking that you'll have to move the pin up on the piston high enough to get into the ring package.

 

Yeah I already got somebody that will make me custom pistons With the adjusted pin location.

 

just my $0.02 but I don't think it's possible dude. The deck height on a F20b is 8.643" and you are looking at 6.02" rods plus 0.5*88mm/25.4=1.73" 1/2 stroke adds up to 7.75". Even with the .026" head gasket you are gonna need pistons with a compression height of only .70". Seems a little tight.

 

also... even with the overbore you need 65.4cc in the compression chamber to get 9:1 compression. The stock CC is only 53.8cc. It seems like you would use flat top pistons for better flame front and lower compression, but even then I think you would need like 11-12cc extra space in the compression chamber. Are you gonna do extreme boring out on the head?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 97LXF20B &raquo;</TD></TR><TR><TD CLASS="quote">just my $0.02 but I don't think it's possible dude. The deck height on a F20b is 8.643" and you are looking at 6.02" rods plus 0.5*88mm/25.4=1.73" 1/2 stroke adds up to 7.75". Even with the .026" head gasket you are gonna need pistons with a compression height of only .70". Seems a little tight.</TD></TR></TABLE>

exactly what I was thinking, I just had no idea what the deck height was on the f20b

 

Just got back to this.LOL. Well the f20B factory rod is 5.7 So whats another .3 gonna do??My headgasket thickness is .126.Im already thinking about getting the head dished and milled. So with the piston pin relocation and the added height of the gasket and head dishing I think I can do it.Right now im just worried about the flame front and TDC hang time.My compression when its all said and done should be 9:1. I want to be able to rev low 11k rpms at about 25 psi. But will see if this happens or not.LOL. If only in my dreams.LOL

 

more power to you if you can make it work...

one more thing - are you sure the f20c rods fit with the f20b crank?

 

what is the point of revving that high and boosting???

 

These will not actually be F20C rods but custom made rods with a length of 6.0in.Reason for doing so is ***** and giggles and because its not imposible.