Hey guys, used the search function to get some general tips on porting cylinder heads, have read a lot of articles, and David Vizard's book so I think I'm ready to tackle it. I have Dart(now World) S/R heads with 1.94/1.5 valves. I plan on cleaning up the bowls, slimming the valve guide boss, raising and straightening the roofs of the ports and get a new valve job and cut for bigger valves and install Performance 2.02/1.6 Valves(from comeptitionproducts.com).

Does anyone have any info on anything specific to the World S/R heads and how to port them(what areas to concentrate on, etc.). Assuming I know what I am doing do you think I could get 240/170cfms @.500 Lift out of them? I've never seen a stock flow test for the 1.94/1.5 valved s/r heads but the s/r torquers give 220/135 or so @.500 Lift so I would expect mine to give 10cfms or so less then that with the smaller valves.

Right now I'm running mid-low 14s(calculated from 1/10th mile time...yes 1/10th)..I'm hoping with the porting I can bring it to NYIRP and get a 13 sec. slip. Thanks guys

 

five7kid and F-Bird'88 are the two guys who know these heads well. I don't think you will need larger valves, though. I think you require a REAL monster 350 to need anything larger than 1.94" intakes.

 

I went straight down the line of the Standard Abrasives Do-It-Yourself Guidelines: gasket match the intake ports, clean up the bowls to 85% of valve diameter, smooth out the short side radius, reduce the valve guide, remove any casting flash and smooth out sharp edges, polish the exhaust ports and chambers.

I would think the Torquers would benefit from 2.02/1.60's more than the plain S/R's, but if you make sure the valves are unshrouded (also discussed by SA - wasn't a problem with my heads), they would probably still help.

As for raising roofs and getting to 240 flow, that would probably be best left to flow bench verification.

 

Make sure you gasket match the heads and the intake.

 

The s/r heads are the same exact heads as the s/r torquers except with the smaller valves. I looked at an article in CHP in which they just cleaned up the ridges in the bowl and unshrouding the valves on a set of s/r torquers and got 226cfms intake and 176cfms exhaust @.500 Lift. They didn't even touch the valve guide bosses which are pretty big and bulky on these heads. If I work these guides over and slim them down and then install better Manley Race Flow Valves (the stock heads come with Manley Street flo valves i think) and I'm thinking with these extra work I can get 240/180cfms @.500 Lift or so. I'm trying to get these things as good as vortecs...think it is possible?

 

Do I have it backwards again? I thought Street Flows had the reduced stem and Race Flows were straight.

I've only had the 350 S/R's and 305 S/R Torquers, so I'm not sure about the specifics of the 350-style S/R Torquers. But, I was under the impression the ports & chambers were different between the 350 versions S/R vs. S/R Torquers (more than just the valve size).

Obviously, not the first time I've gotten something wrong.

 

I think it's definitely possible to get them to flow like Vortecs. I mean heck, you can port up 305 heads to flow as well as stock Vortecs. You could probably get most decent performance stock castings to flow like them, just depends how much meat you need to grind away to get the airflow.

 

With a full basic porting job and the larger valves you should be able to hit your goals.

 

You should do a search for F-Bird88 and Sitting Bull about porting. There are a few good threads that will tell you exactly what you need to know.