Hey guys,

I *might* be getting a pair of TFS 23* G2 heads for cheap, While they're off im going to bowl blend, gasket match, unshroud the exhaust valve, and I've become kind of curious... Anybody know of a way or seen anybody make any modifications to improve swirl? I know they have a "heart" shape already, but could I increase/decrease the angle to give it more of a swirl? or would decking fix swirl issues? I'll already be running about a .040 quench. Thanks!

 

I suggest you leave it alone
best thing you can do is smooth any rough edges in the chamber AND on the pistons (like the edges of the valve reliefs and the piston face itself) and run flat tops
the whole swirl thing is pretty tricky for us mere mortals to be toying with but if you wanna read up on your fill of the subject check out www.Theoldone.com

 

If you want more scavenging swirl, try 18° heads.

 

I suppose if you found someone that knew those heads and knew what they were doing, that you could increase the swirl. If I had to guess, TFS probably spent a fair amount of effort on the final design and theres probably 100x more room for error than improvement. If you go to the link Pablo posted, you will find out you could spend a lifetime making it just a 'little' better.

I'd concentrate more on the area just before and after the valve and leave the rest alone.

 

Ho hum.....

Oh well guess i'll have to leave it alone

 

to unshroud the valve. I think the next most important thing is to have all chambers the same CC to ensure you have equil compression. After those (and only after) have been accomplished should you start looking at swirl.

 

I think that swirl is much more over looked that this thread is suggesting.

Yes its dangerous territory... But c'mon, not every set of heads are a $1,200 set, and this is a sport where we pay $400 for 4 bent and welded tubes?? $1k for an alluminum box with 8 small runners to a $400 base? Swirl and combustion chamber design is a very important step in making horsepower, and untill the vortecs was way over looked just think how those $400 set of heads shed so much light on such an overlooked area.

Granted trickflow BETTER have put some R&D into the swirl and chamber design, but still, its only casting there's improvements to be made everywhere. Just wondering if anybody has experimented and knows what changes do and dont work

Thanks

 

The other parameters are much easier to determine and improve on bc they have some good operating rules of thumb that the averge joe can confirm.

The Sept2000 issue of GM hitech perf had the only test I have ever seen of head airflow that also factored airflow swirl. And I have never seen their results confirmed or repeated by anyone else. And actually, in that test the TFS head did not have very good swirl characteristics. The Vortecs and LS1s came out on top.

 

You think someone here has that sort of information and is willing to part with it? Measuring swirl is far from an easy thing to do, and those that go to the expense of doing it are usually racers and they arent going to give away information they paid dearly for.
I'd have to guess you didnt visit the link Pablo was so nice to post. Try it, theres much more to swirl than the combustion chamber in the head. To save a little time, even the guy there who is probably *the* expert says its best to concentrate on the area near the valve and leave swirl to those with bottomless wallets.

 

I did breifly

and I found that it related more to 4 valve heads in which case flow/shrouding/swirl/intake volume are all a different animal. Yes, i do also think that there are people out there KIND enough to share information that they found out through sweat blood and hard work, granted not many, and less yet that will do it without an attitude.

However I commonly find threades entitled "learn from my mistakes" and so on. Some people enjoy sharing knowledge and helping to further the game of high performance engine building.


Thank you jcb999, you have been helpfull and offered some encouragement.