viking

If you want to pull aprox 400 + hp out of an 13b-re engine, I have heard that you must change the studs that hold the engine together, too some bigger one´s .

Is this true ?

Rub20B

It's called dowel pinning... They add some steel dowels around the engine,



Some people say, at the top and bottom, because there is the most room to make the holes bigger and add dowels, other say you can better place them around the sprak plug area because when the sparks ingnite the mixutre, the pression on the housing is the biggest in the spark plug area.. Maybe also a little higher for bad tuned engines to make the housings more resistant to detonation, but then you'll probaly destroy the apexes..



Rub.

Old Splatterhand

there's also a race stud kit, extreme rotaries (?) sells it, where each tension bolt has the function of dowels.

but according to the experts on this forum, you don't none of these things for your goals

setzep

I think you'll need different exhaust sleeves before you'll need different studs at 400+hp

Rub20B

Put TII ones in and smooth them.. maybe port yuor exhaust ports a bit down..

heretic

That's correct. The problem is high combustion pressure (such as from detonation) flexing the rotor housing outwards. If you look at the way the engine is put together, the important combustion area is exactly the part that the factory dowels do not support.



You can get by with conservative tuning and no dowelling, but many builders (myself included) believe that the "brick shithouse" approach is the best. You don't have to worry about it if it's done overkill.

astrochild7

amen 50 million dowls baby

Rotary Sensei

You don't need to dowel pin at 400 hp.

viking

Thanks for all the info. It have been moast heplfull.

So I dont need new dowels to get 400 hp out of the engine..

But what was the thing with the exhaust sleves.... ?

Dragon

No dowels or sleves needed... Just myths started from the big name shops as a way for them to grab some more of your $.



A decent side port and good turbo will net you 400 with no problem....