camshafts

[boxer3maine]

I was looking around for generalization of camshafts for four cylinders. Found old austin healeys even went to 300 duration.

this is about subes. my old one is 233 degree in the carb days .One bad lobe can leave a bad exit- freakishly tight. So tight a half tooth off in longevity breaks something when they are good. The ea82 finished off with a 244 in the spfi (http://www.youtube.com/watch?v=a3RXh6DQ9xA&feature=player_profilepage#t=58s)(just right, run of the mill). the tiny 2.65 inch stroke seems to dictate how much cam they can get. I had read of 260 degree..about as far as it went. Fear of the 3 main only crushed the market.
the ej..was searching around for vids, sure enough, found some.

http://www.youtube.com/watch?v=zrDh8zvfH6U

272 duration. All beyond 260 is a big shift in rpms..

http://www.youtube.com/watch?v=aNyIAmsX3QU

280. sounds better tuned than the 272 above. :unamused:

http://www.youtube.com/watch?v=CXzpXGNNskU


282..first start got an excuse...although that is a big overlap.

http://www.youtube.com/watch?v=JXyRWuedLA0

300! :eek:

there is some turbo engines in videos, but that is not the point.. this is for relation to n/a. An interesting thing I learned about my old one. the carb and turbo shared identical cams.. why? the carb and turbo are the most powerful versions of any engine. factories runt them.

[Seraphinwolf]

Cams are a GREAT mod for any motor, but the trick isn't just going with the most aggressive you can! Have to pick the right cam profiles to match what you are doing with the car. Delta Cam will do "regrinds" very persicion and quick and a top choice on NA Subarus. Lots of the turbo guys have Cosworth and such on omenof the more intricate variable valve timing heads. The beauty of the variable heads is the ability tonhave a timing profile nice for commuting, leashes drives, etc THEN open up up top and kick some ass!!!

[boxer3maine]

Cams are a GREAT mod for any motor, but the trick isn't just going with the most aggressive you can! Have to pick the right cam profiles to match what you are doing with the car. Delta Cam will do "regrinds" very persicion and quick and a top choice on NA Subarus. Lots of the turbo guys have Cosworth and such on omenof the more intricate variable valve timing heads. The beauty of the variable heads is the ability tonhave a timing profile nice for commuting, leashes drives, etc THEN open up up top and kick some ass!!!

I still believe in a precise center and a profile challenging materials. Not sure where the lopey skip came from losing demand of the good tune. Variable valves must be making up for fails of materials...old pushrod mentality. A boxer being self balanced is also something cam profilers skip over, real shame. they could stay centered right into very large..no games with variable anything.

world record holding cars still have no vtec. A glimpse at what nelson engines has done for street is a good example. Calm idle and 1000 hp ripping it up at the other end.

On my own little sube, the cam swap is what set me into looking around. The solid lifters gain .5 mm all the way around the lifting profile. In the cam world, that is gigantic. A turn and a quarter up on the idle screw and it got its 700 rpm back.

it is fun to get this right. the approach really has to have a boxer expert. Fun seeing the old school lopey mentality on some of them though. :up:

[Seraphinwolf]

Yes solid lifters makes a big improvement on how far you can push it. Converting an EG33 to solid buckets from hydraulic you can safely raise the rev limited from 6.5k to 8k! With a 3.3L H6 that's a LOT of room for a LOT more power!

[boxer3maine]

Yes solid lifters makes a big improvement on how far you can push it. Converting an EG33 to solid buckets from hydraulic you can safely raise the rev limited from 6.5k to 8k! With a 3.3L H6 that's a LOT of room for a LOT more power!

I still ponder subaru simply keeping the hidden race realm to themselves. been happening forever. I bet the eg33 is a very nice run.

the spfi stuff on the old EA solid is exactly just right. any more would be tinkering all the time.

the centering for the boxers is a must. Not sure why they went variable.. an inline is offset forever, hotties in the middle. I can unserstand the insanity there. boxers don't need it. :)