Don Terrill’s Speed-Talk

Charlie, please post a picture of the exhaust port from the flange side

...on the floor where it meets the pinch side (vertical wall) whats your opinion of leaving the radius where they join rather than taking it down some. Affect things how? The corner radius is an area where material is added when you want or need to srink the port down. http://i842.photobucket.com/a...

Carnut1 wrote:Both sides? Thanks, Charlie

Yes, broaden the tight floor/wall corner radius going into the short turn. In that area make the radius very large blinding it into the bowl.

Charlie, one thing I think is worth a try is makeing the port floor corner radius bigger at the apex of the short turn with clay or epoxy for a flow bench test.

So is the consensus that placing a head on a block and tracing the bore to chamber and then pushing the chamber out on both side to match the bore, proper? This is not a situation where you can make a blanket statement. If you look at the engine Bill posted, the chambers go beyond the bore in some ...

It looks like it was getting oil to the bearing but not enough to the cylinder.

I would be curious to know the date of Shawn's piston post...I recall a lot of press around the mid to late 90's about the concave piston as if it was the wave of the future but I don't see much talk about it now? Thu Oct 27, 2005 https://www.speed-talk.com/forum/viewtopic.php?f=1&t=1723&hi...

I did a bunch of that 15 years ago for Nascar guys. The oft used spherical dish was one of my efforts . I also created a "V" dish in the center of the piston to enhance mixture motion. Both made more torque and a slight amount of hp with less timing versus a flat bottom mirror image dish....

isky cams parts number 201526 288 292 254 259 at 50 525 in 548 ex i run 1.6 in 1.5 ex. 106 lobe center. my 355 have 6 inch rods probe piston with very small dome victor jr intake and 800 Holley with 2 inch spacer. 1 5/8 headers 3 inch collectors i do 541 hp and 468 lbs torque. It's an awesome combi...

1127thunder wrote:...iskiderien oval track camshaft 5.60 lift….

Whats the part number for the cam?

What valve spring pressure did you use to get 7500 out of that combo? Reason I ask is its a very similar combo to what I run, and I use 150lb seat, but am wondering if I'm over doing it. I bought the heads from AFR with the flat tappet springs with 135 on the seat. The cam has lobes that are real e...

Here's another example with bigger ports, light weight and more RPM: 9.50 at 140 with an 11:1 flat top 355 in a 2200 lb Super Gas car with the AFR 210s and the Isky 201555, Victor Jr. intake, 830 HP, 5500 - 7500 RPM This combination does not work well in a heavy car, may be so with more gear and con...

We have run the AFR 210 heads on a 355s; they will like a lot of RPM! Your goals are realistic. Here's an example using a smaller port head and the right converter, custom ATI; late 80,s Camaro, actual weight unknown (over 3000 LBS), TRW flat top 355, ported Edelbrock performer heads, ISKY solid fla...

Interesting read:

http://www.enginelabs.com/engine-tech/c ... ur-engine/

Considering displacement only won't give a complete evaluation of the two. You must also evaluate percent VE. If there is a difference in power like some of the experienced engine builders here claim, I believe that's where the power would come from. .https://www.speed-talk.com/forum/viewtopic.php?f...