Precison Race Components Small Runner UPDATE!!
Ben,
You could take 99% of the LS heads out there and find the same thing. The Darts I had in the shop didn't go turbulent at all at higher lift and higher depressions. I flowed them to .700" and at 40" of H2O. In fact most of the problem with the Dart heads is the chamber and how the valve job is in there, all you have to do is fix that and that goes away. Most of the times with other heads it's in the port and takes a bunch more to fix.
Try turning up the pressure on a AFR head on the bench and watch them back up.
Bret
You could take 99% of the LS heads out there and find the same thing. The Darts I had in the shop didn't go turbulent at all at higher lift and higher depressions. I flowed them to .700" and at 40" of H2O. In fact most of the problem with the Dart heads is the chamber and how the valve job is in there, all you have to do is fix that and that goes away. Most of the times with other heads it's in the port and takes a bunch more to fix.
Try turning up the pressure on a AFR head on the bench and watch them back up.
Bret
SStrokerAce, Here is a comment from Dart about their valve job.
Originally Posted by Dart331Stroker
The area between the seats or where they meet dont get hot, the fuel cools the intake seat as it enters the chamber. Again we spent alot of time developing the valve job, and doing extensive wet flow testing, if you look on here you will see a post refering to wet flow testing at ReherMorrison. We showed Darrin Morgan alot of the information regarding wet flow testing, he has been here and worked with Tony McAfee, this would be our Tony. LOL. Anyways the sharper angle helps the fuel to shear of the seat, if you were to round it the fuel would follow that radius and seperate from the air, this obviously would be bad. We have tried to show this on high speed equipment, but do to the dye that is used in the wet flow process we havent found a way to show this on video. We have some people here now from some of the magazines who are very intrigued with the information they are learning and look forward to releasing this data in the upcoming months in several magazines. Other then the seat there are no sharp edges, we even deburr the chamber edges leading to the quench areas.
Thanks
JC
Thanks
JC
Can we get them in a 2.00/1.60 valve setup?Also is there room for a 60cc chamber without intake problems?(I don't know if you milled them for 62cc)
Some of you guy's have to test small runner setup's.We already did and I prefer small-good flowing runners. You can run a small runner with a small 224 Cam and make awesome midrange hp/tq.I've seen mild setups put out 435hp/430tq in emmision legal stock sounding cars which also run mid 11's at full weight.
Some of you guy's have to test small runner setup's.We already did and I prefer small-good flowing runners. You can run a small runner with a small 224 Cam and make awesome midrange hp/tq.I've seen mild setups put out 435hp/430tq in emmision legal stock sounding cars which also run mid 11's at full weight.
