Ported Dart pro 1 pre platinum

[randy331]

Are you welding the pushrod up to widen it and run shaft rockers?

If not it won't peak higher than 6700-6800 rpm. All the big camz and tunnel ramz won't make it peak higher.
Where I dyno there's been quite a few AFR headed 406-434 SBC on his dyno with 210-245cc heads in various configurations, cams, comp etc.
And none peaked any higher than 6800 or so. I don't remember any making 700 HP either. CGT on here is in the shop more than me and may remember one that did. That type of engine with a better budget in that shop gets Ron's heads, and they do better.

So work on making a well matched combo with 6700-6800 rpm in mind.

If you can make 1.4 LBs of TQ per cube at 5200 rpm and hold on to %90 of that TQ till 6750 rpm, you'll have your 700 HP.
1.4 LBs per cube should be doable with solid roller, comp, ported intake etc.

434 x 1.4 = 607.6 for a peak TQ target. 607.6 x .90 = 546.84
546.84 x 6750 / 5252 = 702.81 HP. See how easy that was. Piece of cake.

Randy

[Carnut1]

Port #1 has been pushed about as far as practical I fact I would use some expoxy and some tape measure steel for strength. Offset rockers have not been discussed. I will need to start computer sims with what I know now and work from there. Thanks, Charlie

[CGT]

Please no laughing, 700 hp, 434, street drivable using these heads. Possible tunnel ram, possible dual fuel injections tbi.

Compression? Pump gas? Camshaft?

[Carnut1]

All subject to change 11+, e85 or alcohol, solid roller.

[CGT]

All subject to change 11+, e85 or alchohol, solid roller.

E85 or Methanol will definitely help your tq per cube early, should make your 700hp goal easier for sure. I've seen a few 414 to 421 sbc's with heads ported the way yours are, make 660 to 680hp on Race gas, one make almost 700 on Q16. 260 ish solid rollers. I'd think 700 would be doable.

[zums]

Are you welding the pushrod up to widen it and run shaft rockers?

If not it won't peak higher than 6700-6800 rpm. All the big camz and tunnel ramz won't make it peak higher.
Where I dyno there's been quite a few AFR headed 406-434 SBC on his dyno with 210-245cc heads in various configurations, cams, comp etc.
And none peaked any higher than 6800 or so. I don't remember any making 700 HP either. CGT on here is in the shop more than me and may remember one that did. That type of engine with a better budget in that shop gets Ron's heads, and they do better.

So work on making a well matched combo with 6700-6800 rpm in mind.

If you can make 1.4 LBs of TQ per cube at 5200 rpm and hold on to %90 of that TQ till 6750 rpm, you'll have your 700 HP.
1.4 LBs per cube should be doable with solid roller, comp, ported intake etc.

434 x 1.4 = 607.6 for a peak TQ target. 607.6 x .90 = 546.84
546.84 x 6750 / 5252 = 702.81 HP. See how easy that was. Piece of cake.


What min csa are you basing that on, i dont recall his pinch csa, and throat is already big
Tom
Randy

[zums]

wtf^^^

[randy331]

What min csa are you basing that on, i dont recall his pinch csa, and throat is already big
Tom

I based that on a 2.4" MCSA.
I think he had posted 2.44, but I figured 2.4 as an effective CSA.

I'm not saying it will make 700, just I'd approach it from a make all you can below 7000 rpm stand point, unless the pushrod area is to welded.
In other words, size the port area before and after the MCSA for under 7000.

It could easily fall short of 700 too, but that should be possible with 434 cubes.

More comp than 11-1 would help. Comp is easy to get with 434 cubes.

Randy

[racear2865]

What min csa are you basing that on, i dont recall his pinch csa, and throat is already big
Tom

I based that on a 2.4" MCSA.
I think he had posted 2.44, but I figured 2.4 as an effective CSA.

I'm not saying it will make 700, just I'd approach it from a make all you can below 7000 rpm stand point, unless the pushrod area is to welded.
In other words, size the port area before and after the MCSA for under 7000.

It could easily fall short of 700 too, but that should be possible with 434 cubes.

More comp than 11-1 would help. Comp is easy to get with 434 cubes.

Randy

You shouldnt even have to put a knot on the piston.
reed

[GARY C]

You could figure that a decent porter could get this gain without doing the guides and valve job which would need to be in either excellent shape or done by a pro. Chamber to this point is stock shape.

I prefer to do the chamber first so that I know it is not hindering the flow of my port work, I have seen in the past where a port ends up to big by chasing flow in the port only to find out that it was the chamber holding it back.

[Carnut1]

You could figure that a decent porter could get this gain without doing the guides and valve job which would need to be in either excellent shape or done by a pro. Chamber to this point is stock shape.

I prefer to do the chamber first so that I know it is not hindering the flow of my port work, I have seen in the past where a port ends up to big by chasing flow in the port only to find out that it was the chamber holding it back.

I decided to do port #2 guides and valve job first and test #2 was the chamber. With stock ports the chamber work wasn't that much gain. I was expecting much more from the chamber. Thanks, Charlie

[GARY C]

The chamber it's self will not be except down low in most cases but it can become a hindrance as the port gets better if it's not sized/shaped properly for the valve size you are running. The chamber/pressure recovery is part of the intake system and has to work together with the port, if the air can not get over the valve and between the valve and chamber wall efficiently then how can it get out of the port?

Judson with S.A.M gave an example of a highly developed head they had, they decided to raise the compression on the engine by angle milling the head 1 degree and lost over 20 CFM because of the effect it had on the chamber.

EDIT! If you have a test head it would be worth wile to test different chamber shapes and lifts.

[Carnut1]

The chamber it's self will not be except down low in most cases but it can become a hindrance as the port gets better if it's not sized/shaped properly for the valve size you are running. The chamber/pressure recovery is part of the intake system and has to work together with the port, if the air can not get over the valve and between the valve and chamber wall efficiently then how can it get out of the port?

Judson with S.A.M gave an example of a highly developed head they had, they decided to raise the compression on the engine by angle milling the head 1 degree and lost over 20 CFM because of the effect it had on the chamber.

EDIT! If you have a test head it would be worth wile to test different chamber shapes and lifts.

I wish I had test heads to cut up.

[GARY C]

The chamber it's self will not be except down low in most cases but it can become a hindrance as the port gets better if it's not sized/shaped properly for the valve size you are running. The chamber/pressure recovery is part of the intake system and has to work together with the port, if the air can not get over the valve and between the valve and chamber wall efficiently then how can it get out of the port?

Judson with S.A.M gave an example of a highly developed head they had, they decided to raise the compression on the engine by angle milling the head 1 degree and lost over 20 CFM because of the effect it had on the chamber.

EDIT! If you have a test head it would be worth wile to test different chamber shapes and lifts.

I wish I had test heads to cut up.

You may want to check with Vizard and or Dart, sometimes you can get them to give you a blem or damaged head.

[Carnut1]

These are out of production pre platinums so no idea how many are around. Thanks, Charlie