Dyno 308 vs Dyno 275 vs NR274

Dirtkartin

New member
I am wondering what is better for my clone. I already have the 308 and 275. I was told the NR 274 would give me the most power with my application. I have 27/24 SS valves, 304wx tilly on gas, head milled 50 thousandths, .20 ARC rod, flat top piston, 26 lb springs.

I run mainly short tracks, one I can flat foot for 8 second laps and one is a flat track that is a couple of seconds slower.
 
I believe the 308 is all out rpms on a mostly flat foot track.
If you have to lift I would think the 275 might be a bit more torque on the low end.
But if you can have a high stall, or keep rpms up the 308 is good...
In the end...what ever gives the best lap times...
 
what RPM's you turning or want to turn, We run a really small track, 1/10th mile, I had a 307 was to much, running the NR280 now, buddy has similar build and runs the 274 and it pulls like a train.(we both run 1.3 rockers) Wish I would have gotten the 274 for such a small track, the black mamba and black mamba jr are supposed to be really good cams, also the MOD-2 cam I had in another engine with 1.3 rockers and 26lb springs was great on the small track.
 
I am wondering what is better for my clone. I already have the 308 and 275. I was told the NR 274 would give me the most power with my application. I have 27/24 SS valves, 304wx tilly on gas, head milled 50 thousandths, .20 ARC rod, flat top piston, 26 lb springs.

I run mainly short tracks, one I can flat foot for 8 second laps and one is a flat track that is a couple of seconds slower.

26lb springs will be too light with the 274. 37lb is recommended
 
We run the NR-274 with the 37 lb springs, Honda GX-200 block milled .020, head milled .050 with a wx-304 tilly flat top piston , and we do short tracks in two different areas .....it all works great for us. jmo
 
How about 308 with 1.3 and 26 springs and many battles won !
it can be done,its all in the build and what you want the engine
to do.more is not always better.jmo
 
308 with 1.2's on a short track, I have two of them and I guarantee there is no 275 out there that will hang with it. I have a Clements f275 with 1.3's advanced 6 deg. Just to get closed to the 308 with 1.2's. So it's deffinately the 308 hands down.
 
DynoDark used to post about the 308 and had a thread about grinding it down to 302 to hit the sweet spot. Not sure if anyone has an archive, but he had numbers to back it up.
 
NR 274 with billet 1:2 rockers ARC long rod Wiseco flat top piston Milled and ported head with 37mm int and 29mm ext Val's with 37lbs springs also a Tilly works well on short and long tracks
 
I have run 274/0207,274/0627,274/1007,nr285 and agk 276, on 1/8 mile the 274/0207 was the strongest cam! (Great cam!)
 
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