RE: Numbers for ST G21/35 DDD head
As usual with this kind of discussion, that of 'power' everyone ignores the elephant in the room.
The tuned exhaust system. The bane a diesel, the savior to a glow.
Martin, almost the entire MVVS glow range is designed to work best using a tuned exhaust system and yet those old testimonials never use or mention them - strange that.
Want a true 30% power increase? Then try using a mini pipe equipped MVVS glow against a similar diesel.
The cost, MVVS usually don't come with any form of muffler so there is no real loss when choosing a pipe over a canister muffler but lets say that you have any existing engine with a standard canister muffler and want to increase power.
$60US will get you either a diesel head or an MVVS mini pipe - which do you think will give you more 'power?'
I have Dar Zeelons old MVVS 49 converted diesel and even he knows that it will not out perform the same engine as a glow on a pipe.
A search here will reveal that originally he thought that the diesel won out and that's what he 'wanted' to believe at the time but upon a second checking of the figures both configurations using standard canister exhaust system proved to have about the same amount of power.
Add the pipe and its a no brainer really.
And I dare say that an OS Max 40 with the cost of conversion head thrown instead at a tuned exhaust system would out perform a diesel - the sticking point here how you want to run the engine, power bands and emotions and I am not saying that one is better than the other.
Cheers.