I need swirl head info

[airagitated]

Can any of you fine people show me the way to info on porting a swirl head?
Any links with pics or written info would be great. My engine guy is having a hell of a time trying to get decent numbers with +2 valves. I had told him it was a tricky job to do, but he felt confident he could pull it off without killing the velocity. My brother's car has been down all summer and this has gotten out of control. I had contacted a select few people on this board that I feel have unlocked the key to this head. When I didn't get a timely response I went ahead with my only option. I fail at the whole search thing so if someone can help me out that would be great.
Thanks,
Mike

[88C/S]

This person knows how to do it - http://www.geocities.com/portedheads/
Don't know if you tried contacting him.

[airagitated]

Thanks for the quick response. At this point I'm looking for pics or other posted info that I can use to get this thing done. So any posts with measurements or pics of swirl heads that flow well would be what I'm after. I really don't want to take up someone's time If I'm not making a purchase from them. The head is not going to flow as well as I had hoped and at this point we no longer care. We would just like to get the car together. So any posted reference material would be great.
Thanks,
Mike

[turbovanman²]

Not really too many measurements floating around. If unsure what your doing, just open up the ports a bit, bowls, deshroud the valves and a nice 5 angle valve job with back cut valves and or under cut stainless valves.

[airagitated]

Thanks Turbo. That is about where we're at. What I think I'm going to do is get some pics and the current flow numbers and post them on monday. That should give everyone something to critique.
Thanks,
Mike

[OmniLuvr]

i think the deshroud is VERY important on a swirl head, more important with more boost and bigger valves, my opinion.

[BadAssPerformance]

Thanks Turbo. That is about where we're at. What I think I'm going to do is get some pics and the current flow numbers and post them on monday. That should give everyone something to critique.
Thanks,
Mike

pics and flow numbers should help... is th ehead in your possesion, like next trip to Grove we could see it?

[4 l-bodies]

Mike,
Have your motor guy flow bench one cylinder. Then you will have a base line.
Concentrate on the short turn and the pocket area. If your motor guy is good, you can have him lower the floors on the exhaust and raise the roof. There are gains to be had there. Be careful with the raising of the roof, as there is a waterjacket if you go crazy. Pics are on this forum of cut-aways of the swirl head. I would suggest you print them off and give it to the guy porting. If he doesn't think he can get to all of the short turn after lowering it don't have him try it! It's time consuming, and you need the right carbide cutters and sanding rolls and not done properly, it will hurt flow.
If your not planning on porting the intake and exhaust manifold to match, I wouldn't bother porting too much as you will see negative results because of the mismatched ports.
If you do some porting in the ports, the intake will tolerate and like a much larger port volume. Don't go too big on the exhaust or you will kill your velocity. Think straightening the ports not just enlarging.
Unshroud valves if you are going bigger valves. Not sure what you mean be +2 valves?
Error on the side of caution when porting. I've seen big gains just with good valve jobs and working exclusively on the short turns and removing casting flash in ports and around guides.
Then after this is done have him flow bench the same port and see what you accomplished. Hopefully you will have gained some flow to go along with your depleted wallet.
Good luck!
Todd Nelson

[airagitated]

Thank you all for your time and input. The numbers are acquired using a calibrated flow bench. Russ, the shop owner, has been treating the head with kid gloves per my warning. We have the cut away pics and they've been great. Valve size is +2mm over stock or a 38mm and 44mm rounded.

The head when we started had +1mm valves deshrouded and light port work. Here are the base line numbers:

Lift Base Current
0.50 22.3 26
100 46.3 49.9
200 95.5 96.1
300 137.8 134.8
400 152.5 152.5
500 150.8 160.2

The current numbers are with the big valves, a bit more porting and chamber work. Are these numbers good or bad? JT...I can get the head at any time and will gladly bring it to you.

I have pictures, but I have no idea how to post them. JT...HELP!!!

Thanks,
Mike

[BadAssPerformance]

I have pictures, but I have no idea how to post them. JT...HELP!!!

Thanks,
Mike

e-mal them to me jt @ badassperformance . com

[airagitated]

Pics away!! Thanks JT! I owe you beer.

Mike

[BadAssPerformance]

lotsa pics mmmm beeeer

[airagitated]

Dude you are the man!!

[BadAssPerformance]

I aim to please

So, you gonna walk us thru each pic as to what we're looking at?

[4 l-bodies]

Thank you all for your time and input. The numbers are acquired using a calibrated flow bench. Russ, the shop owner, has been treating the head with kid gloves per my warning. We have the cut away pics and they've been great. Valve size is +2mm over stock or a 38mm and 44mm rounded.

The head when we started had +1mm valves deshrouded and light port work. Here are the base line numbers:

Lift Base Current
0.50 22.3 26
100 46.3 49.9
200 95.5 96.1
300 137.8 134.8
400 152.5 152.5
500 150.8 160.2

The current numbers are with the big valves, a bit more porting and chamber work. Are these numbers good or bad? JT...I can get the head at any time and will gladly bring it to you.

I have pictures, but I have no idea how to post them. JT...HELP!!!

Thanks,
Mike

Okay Mike,
The #'s you posted are they intake or exhaust? Usually one would post both #'s. If they are exhaust, not bad! If they are intake, keep working on it (lol)!

On a turbo motor don't worry if the CFM flow of exhaust % to intake gets too high. 75-85% is ideal for N/A applications, but turbo applications will tolerate much more than 85%. I've seen 16V turbo heads that the exhaust outflowed the intake!

On my 8V heads, I can see gains of 50+CFM on both intake and exhaust on a +1mm or BV head vs. a stocker @ .500 28" depression. This took a long time to figure out what works and what don't. You not going to hit the ball out of the park on your first at bat. Settle for a stand up double. Stay conservative and take notes of what you do, and how the bench reacted.

What seats did you use for the intake/exhaust? I really had to laugh back in the day when MP would sell their BV seats. First off, they were horribly expensive. On the intake, the ID of the BV seat was SMALLER than a stock valve by .045 even though the valve diameter size was increased by .130! On the exhaust it too was smaller than a stocker, but much closer. Certainly one can correct this, and common sense should tell any machinist that the seat ID needs to be opened up, but no where did MP offer to tell you that!

As far as bone stock flow #'s I commonly see around 110-120 CFM exhaust and 140-150 intake @ .500 on a NOS stock swirl on the bench I use. This would be a NOS or perfect "Mopar" swirl. Not one that has had 100+ rounds on her. I've seen #'s much lower posted elsewhere for stock heads, and I sort of question whether the heads were really up to snuff or not. or if they were aftermarket castings. I've benched quite a few of them. IMO, a good BV swirl (or g-head for that matter) head should be flowing around 200 intake and 160 exhaust or higher @.500. These #'s obviously would be based on the bench I use. I one I use is also calibrated on a regular bases.

Don't get too caught up in bench #'s. No one won any races on the flowbench. Use it as a tool.

Todd

[airagitated]

Man I'm brain dead. I'm gonna say he gave me the intake numbers. I know they are low whitch is why I wanted to get some other input. 200 intake and 160 exhaust is about where I thought it should be. Let me collect a bit more info. Ill be back. Thanks for the help thus far.

Mike

[4 l-bodies]

Dude you are the man!!

JT thanks for keeping pics small for us that have dial up! What a guy My initial thoughts are porting looks pretty good! Seat ID's look small, I do far more work around guides. I always knock out guides on exhaust and replace with tapered manganese bronze with stops after porting. IMO, they are always way too sloppy. I do intake too, but it doesn't effect port work. Valves look a bit more sunk in than what I normally do, but it could just be the pic.
Mike do you have any measurements of seat to valve tip height? No shims, seat floor to valve tip height. That will sort of tell me how far they are sunk in. Production heads are around 1.985" How about any seat ID's?
Todd

[airagitated]

So I made it out to the shop today to gather some more numbers. Unfortunately Todd I didn't see your latest post til now. I'll get those answers for you tomorrow. The model of the flow bench is a Super Flow sf 600. Measurements are taken at 28" of water and through a 3.5" bore. The valves are stainless and measure as follows:
..Intake valve 1.735" dia 5/16" stem 45 degrees under-cut stem to .290....Exhaust valve 1.500" dia 5/16" stem 45 degrees no undercut. Russ was thinking along the same lines with the Seat ID. He asked me to post this question. What's the optimal Seat/Bowl ID compared to valve OD? He thinks the seats that he used are too thick. The second part to the question is what brand of seats should we use? Part number for the seats? He can't take any more out of the bowl without taking more from the seat. As far as flow numbers go the ones posted are the intake. The exhaust numbers are even worse. This is sad. He's barely touched the openings of the intake/exhaust. Most port work that has been on the intake side with the intent of straightening it out. Not much port work has been done to the exhaust side. All of the pics posted are from the same port and chamber. It's the ginny pig. I'm sorry if they aren't very good. I don't know the best angles to take. Well that's all I have for now. Thanks for the great help!

Mike

[BadAssPerformance]

Thanks Todd, but I cannto take credit, that's the size Mike sent them

Seats... The IMSA heads with 44mm/36.8mm have separate seats... the 44mm/38mm heads Forward Motion sells have interlocking seats.