Colt4g63

My AB Mods Team driver Brian Dunbar who is also sponsored by Team Orion came by today with the new US Spec Team CRF .21 engines. They have made some changes on the engine such as sleeve port timing, crank timing, back plate and a new drilled/lightend cooling head. So I'm going to break them in and do some dyno testing etc. Heres a sneak peak of the new Team US spec Orion CRF .21 offroad engine!

SAVAGEJIM

That is a great looking engine! When you have a chance to put it to the dyno, dont hesitate to let us know if thise engine lives up to the Rossi lineage!

HerrSavage

I think the Orion team just cleaned up with that engine over here in Germany..

It's what I would get if they weren't so expensive.

nitrokingz

hey adam , i was going to order the team orion .21 when do the u.s spec come out. and what is the price tag

Over_revO

The engine look nice!
Cant wait to see the numbers versus the other CRF .

Colt4g63

I'm not exactly sure when they will be in stores. Shouldn't be too long though I wouldnt think

Colt4g63

Stock dyno results are in. Very impressive for a stock mill with a 6.5mm carb insert!

rc rock

^ whyd you have to put the insert [:'(] jk. are you going to modify her???

Colt4g63

The insert was in as this is the way my driver runs the engine. In competitive racing fuel milage is VERY important and these engines are known to be a little on the fuel hungry side.

I plan on having a modified dyno up of this engine before long but maybe not this week it all depends... Dunbar needs the engine for a race at CRCRC here soon and I have A LOT of customer engines to do as im fairly backed up from taking a few days off from being sick.... So I might not have the dyno up this week, it all depends on how much I get done and if I have time to throw it on the dyno after I modify it this week.

rc rock

was just kidding man. actually due to this i'm thinking of creating a 1/8 scale gt racecar using a .18 engine (modded 18 tz.)

Colt4g63

Well I got some free time today and got to work... Here is the stock Vs AB Modified dyno graph layover.

Over_revO

Thats pretty impressive Adam!
I dont know if it was still the 6.5mm restrictor, but it would be awesome result even for 9mm insert


Nice work again!

fabrimacator21

Wow 87 oz-in. That is VERY impressive for a .21. Nice work man.

Colt4g63

TQ is actually 67.24 I have yet so see ANY .21 engine hit 80 OZ-In on my X-Dyno. The Picco .28 and the OS .28 hit high 70s TQ for example

Colt4g63

Believe it or not thats actually on the same carb restrictor... This is a very impressive engine! Now remember these are the 2 BEST pulls stock and modified. I run the engine for alot of pulls and post up the best of both stock and modified that I can get out of the engine. The engines are pushed hard on the dyno..... One reason I dont dyno engines for customers

Im sure as cold as it was out when I dynoed this engine that it might make close to 1.8HP with a 9 mm insert if I had to guess from previous testing with inserts. But I didnt have time to set out there and let the engine cool and retune and run.. etc. Its quite a proccess.... And this is the way the engine will be ran so I just chalked it up and called it a day and got back to my other work. That and my driver needs this engine for a race soon and I didnt want to keep stressing the engine and risk hurting it just to get some high dyno #s. And although the small carb restrictors that are run in alot of these engines nowdays to get better fuel economy do restrict power some they dont really hurt the power as much as you would think! Honestly from all my dyno experience I dont think even with a perfect tune and the cool dense air I was testing in that this engine would make over 1.8HP in its current state with a 9mm insert. And another thing is the CRF crank design doesnt have a big inlet on the crankshaft... SO IMHO the bigger carb restrictors would have even less of an effect on these engines due to its design on the crank inlet. I am actually very fond of the CRF crank design. It has proven to work VERY well time and time again. They dont have to have huge inlets and 9mm inserts to make power and thats been proven in my eyes time and time again through my personal testing

Over_revO

Thats some good stuff Adam, thx for sharing it

Colt4g63

NP Mike, Im always glad to share and help when I can. I hope that people have found this information useful. There is so much mis-information on the internet these days so i try to do my share to bring factual results to the table.

nitrokingz

hey adam would you recomend getting the old crf or waiting on the "US spec" mill

Colt4g63

I would wait on the US Spec.

HerrSavage

...or hope that the older one goes down in price...

The normal one is flat-out nuts.. Just too pricey.