And what did you do about the big tension bolts?

I just drilled them out on my new iron, and when I tightened it, there wasnt enough meat left and it cracked the damn thing...now I am going to have to weld it up before I can run it...just wondering what others have done about this?

Pat

 

You can use a COSMO rear iron and drill it out. I think the rear iron on the cosmo is beefier. This is what is on my 20b due to coolant seal corrosion on the rear from a popped JSPEC engine.

 

i fixed the FD one, and it has been running for a hundred miles or so now, seems to be working fine.

tips for anyone trying to do this:
1) the port is different, you have to spend some time with a die grinder
2) the big dowels are 12mm, but they are tapered at the ends, so drill them to 1/2" (12.9) and then use a die grinder to taper them and test fit a dowel.
3) there are no holes drilled for a couple of the mounting positions, so unless you are using FD mounts, you will have to drill and tap them.

 

Is there less meat on the FD irons compared to the 20B rear irons? Some people are complaining about cracking with the FD rear iron.

 

i don't belong to the 20B club just yet, so pardon the ignorance, but what exactly are you guys doing to your original rear housings? is it just a matter of the power levels you happen to be running or is there some structural issue with the original housing itself? just wanna know ...

thanks.

 

^housing? or do you mean iron?

 

i was referring to the rear iron. i just want to know if it's because of the power levels these guys run or if there is an inherent weakness in the 20B rear - sort of like the S4 engines' dowel area.

(front, intermediate and rear) side housings = irons.

 

the A and B series irons had much smaller dowel pin lands than the fd one, and they tend to break. this was fixed on the c series, so after that it is not a problem.

pat

 

gotcha ... so the A- and B-series engines would be like the S4s of the 20B series.

 

exactly

 

if you end up needing a rear plate... send me a PM... i got a couple

 

Did you countersink around the bore after drilling?

 

yes, but not enough the first time...lol

 

I had corrosion problems along the water jacket because of coolant sitting in the engine while in storage.