Hmmm. I guess the Dart headed one, as I'm guessing that's the one that's closest to my 385 with AFR 195 heads.
Wonder why single plane intakes run, start and idle better than dual plane intakes on a big block?
- Thread starter 450bench
- Start date
Ok, that one uses a Crane Solid Roller cam.
.625 lift
260°/270° duration @ .050
106° LCA
Hope this helps.
You would laugh at the the specs on the other puny little cam that runs 10.90's
Thanks. Captain Obvious thinks that's pretty racy.
It runs great at the track. My 358 SBC Roller is a little more tame, .600 lift with 250° duration @ .050 on a 108° LCA
Just make sure you have/or can get the CR up to add the 20-30* @.050 you looking for.
Compression on mine is right at 10.25 with an .039 gasket
I'm more curious than anything. I'm also gathering parts for a 408 BBC, and probably will lean towards a roller with more duration and LSA than the sbc I have now. It also will be at about 10.25 - 10.30 cr with the heads and pistons I'll use.Compression on mine is right at 10.25 with an .039 gasket
Well, if you move up with a cam in the 250*+ @ .050 range, I'd move up the CR another .75 at least, but then the engine personality and "range" changes as well, and that may not compliment current gearing or street manners.
What I think is so funny about single plane intakes is that a lot of people have to port them to get max performance out of the single planes. Seems to me a lot of them are not that good out of the box. That's the beauty of a Dual Plane intake is they work so good to 6500 with no work. Take the 300-36 Holley Fantastic intake same as the old Z/28 design and people still want that one today.
Good points 1980RS, and sometimes the term "porting" is used but "gasket matching" is actually done, and in some/many cases it's actually ruined, or hurt the engine potential performance more than it helped in many cases. I also have found in several cases that true Dual Planes can be "under carbed" and open plenums somewhat over carbed considering the engines requirements and effective rpm.
Some intakes are just so bad with casting shift and horrible port alignment it's not even worth putting the time in them, they are "New" and fuked right OOTB.
Here's 2 dyno sheets, same engine/dyno/fuel/timing/temps/carb, 4 hrs apart on the same day. Each intake was prepped by me and tuned as well, spacer(s) combo for each intake was optimized.
Not hard to see the trends by the rpm's in where the DP and OP like to operate in, it depends what the engine is going in and used for. The dual plane was getting funky in the upper rpms, even though the 333 cubes, without the spacers on the dual plane, the numbers were more spread apart.
Some intakes are just so bad with casting shift and horrible port alignment it's not even worth putting the time in them, they are "New" and fuked right OOTB.
Here's 2 dyno sheets, same engine/dyno/fuel/timing/temps/carb, 4 hrs apart on the same day. Each intake was prepped by me and tuned as well, spacer(s) combo for each intake was optimized.
Not hard to see the trends by the rpm's in where the DP and OP like to operate in, it depends what the engine is going in and used for. The dual plane was getting funky in the upper rpms, even though the 333 cubes, without the spacers on the dual plane, the numbers were more spread apart.
sandlapper
Veteran Member
for sbc with aftermarket "4-bbl type" EFI (fitech,sniper etc), I've read that a single plane works best (dunno why) --- also noting how one of the lowest/shortest intake is the old EB pn 5001 Torker II --- seems it remains in production too. Seems I did have one somewhere --- recalling it uses a very small runner gasket opening.
