Guys,

I have an early 4 bolt CD EJ20G block that I'm using for my build.

Is it possible to have these converted to 8 bolt for some extra rigidity combined with a 6 speed, if so worth it?

Looks like it may be just a matter of building it up with a welder and tapping into it, or not a good idea?

__________________
500+hp and helis on tap, eta - June 2025.

I would be careful, TIG generates a lot of heat, it may distort the cases.
DO the dowels even line up? THat's the biggest issue, without dowels, it will jump out of gear.

__________________
Its just the internet dude, its not real.
F.B. Racing
01 WRX (STI badged)
2010 XR5 Focus
06 Impreza Hatch 2.0i

i think you will find it way to hard to do and it easier to just convert the 8 bolt in to a 4 bolt. Doug knows how to do it.

It's not required at all. Just insert a stud for the lower starter motor bolt and run it as is. The dowells are in exactly the same place, it's more important that both dowells are installed than anything else.
(it's worrying how many gearbox/engines have none or only one)

Doug, you will be fitting it when the time comes. I have the dowells just wanted to see if it was possible to add some extra strength by way of more bolts in the casing.

__________________
500+hp and helis on tap, eta - June 2025.

doubt its necessary, if you were going to break or split a 4 bolt gearbox housing, an 8 bolt would probably have broken also, thats a lot of power!

__________________

Long live the WRC

Yeah, I can sort the stud out for you no problem. The 4-8 bolt thing was more about adding strength to the old 5 cogger, nothing about engine strength. The 6 speed has a steel bearing support so it's not an issue at all to only have 4 attachment points the engine. Some of the fastest Subarus around have 4 bolt engine blocks.

run 6 speeds in the rally cars with only '4' bolt set up, 4 extra bolts of weight

-3 extra bolts of 'weight'

unless you leave the starter motor hanging on only one?????