Hi. I'll post my situation first. Car is a 1/4 mile oval dirt racer.

I have a f20b with bisimoto 86mm pistons and rods. Ferrea roller rockers. Crane vtec delete cams. 52mm twm itb's.
One of my pistons and the rod is shot.

Do I. ..............
1. Just replace the piston and rod. Quite expensive due to them being made to order.

2. I have a virgin sleeved h22a block with 50mm mains that i could get rods and pistons for at about the same cost.

3. Buy and install a h22 crank with 55mm mains, h22 rods and purchase a single bisimoto 86mm replacement piston. Giving me 90.7mm stroke with 86mm bore but advantage of 55mm mains and iron liners.

4. Ditch the lot. Sell off the cams etc. Itb's and go with a stock k20a.

Please tell me your opinions.

Many thanks Adam

 

This is completely in the realm of personal preference, budget, and time constraints.Everyone may have a different opinion and you know your situation better than all of us. You gave no information about the track or anything to really help you base such a decision off of.

 

If it were me I would opt for option #1. I base this entirely on the K.I.S.S. method.

 

Is the crank fuct? If not, yeah I'd k.i.s.s also. At least to get back on the track.
Then build you a back up motor.

 

Hi, thanks for the replies.
sorry if i'm not with the times, but what does K.I.S.S ?
the F20b crank is good, but has had 10 thou off the mains before.
i was thinking the 2.2 crank would give me a little more tq, obviously i'd have to reign in the revs a little. was turning to 8900 on the f20b.


time isn't really an issue as i wont be racing again untill next march.

 

k.i.s.s.

(keep is simple stupid)

 

kiss.. never heard of it before.

i stripped my h22a7 block down to check the crank, its mint.
but what i have noticed is that the pin end width of the h22a7 rods is 22mm, give or take, and the f20b rods are just shy of 24mm. i was under the impression that the h22's all had the 24mm little end widths.

but is it important? does the pin end width matter as they are floating anyway?


many thanks Adam

 

Ok. I've made up my mind. Going with the h crank and rods.

now. What are my options for rods on an all motor h series. .......
I'm thinking about the carrillo pro A's due to weight. What other options are there?