Don Terrill’s Speed-Talk

This past week i succumbed to the fact that I can not prove out the idea that a longer exhaust port for my head can help, hinder or make no difference at all except for on the track testing. The only bit of info I found was in Pipe Max program files showing exhaust port lengths from 2.3"to 2.5&...

I made a 2" extension on my lathe to make a better fit to the ex port and tested it. I found the numbers given to me by the porter were way off and there is a "buffeting" sound with the manometer fluctuating a full point. I took a 24* valve out and put in a 15*. It helped out the prob...

I find myself trying to find a solution for a set of heads I had worked a while ago and the business that performed the work is gone and I cant get in touch with the owner either. My project is a "LSR" 99" V-Twin. With the mountain man hours I have in flowing and researching exhaust p...

BTW I got with John at Ferrea today and confirmed they had been selling this product years ago but had dropped it because $2400 was a hard sell for the in pro mod series they were selling it to. John also made mention the push rods require special made tips to be reliable and had no cup tips as I wo...

It appears they may have. I remembered a conversation last night I had with Ferrea a few years ago and I believe they carried them, I'm going to drop them a line. I found a pdf from 3M about the product. 3m aluminum matrix composite pushrods HTTP//solutions.3m.com/3MContentRetrievalAPI/BlobServet?...

I came across an uncut set of AMC pushrods while Jesel was finishing up my order so I sent them on over to Steve. He attempted to machine them and install the tips but had an issue. The pushrod started to facture so he sent them back me saying to find someone that's had experience with machining the...

I've seen a lot of this striations/scoring business in air cooled v-twins running forged pistons including my own. During my own experiences I had a ring company even tell me I had fuel loading between the rings causing a spark knock blowing off the moly as a cause. Also had most all the reasons men...

Thanks for the pics and replies.My next question is are these drain back lines REALLY needed on a dry sump motor?I have not ordered push rods as of yet and that will probably be a while , but was wondering about oil restrictors in the pushrods to help limit upper end oiling? I do not think restrict...

First thought would be the tensioner is used for clockwise rotation being mounted on the bottom. Having a second engine would consider the front engine a slave and tension on that chain would reverse on the drag. The front engine needs a racheting sprocket to drive the rear engine but disengages on ...

What I notice about all those pics is that ports are raised in comparison to the standard. Ports that aren't "raised" will have a D. Trying to get 160+cfm out of a non raised round port is very difficult unless you raise the floor.

rfoll wrote:Does all of this mean the D port shape is meaningless?

On a D-port I would weld in the match in the pipe ( a floor). I wouldn't say it meaningless.

I have never been a fan of a larger exhaust pipe than the Id of the exhaust port. Its like saying my exhaust valve is to big and there's going to be reversion so I need a step? When the exhaust flow de-attaches is slows and the blow down circuit has less a draw on the intake. IMO make it close to sa...

I mentioned this in another thread but thought I'd start a separate thread when I found more changes. I did the auto update last night on dynomation5 to v5.16a......and its numbers are quite different from previous versions. A 5.16b came this morning and didn't seem to change anything. I've been wo...

The intake is still Siamese (but not by choice) and has a 7.5 sq in opening into a plenum approx. 105 ci with an 80mm tb attached. My rpm power making goal is 8200. Had I built a longer stroke other than the 3.5" or used 8" rods, Individual runners would have worked. Raising the ports was ...

I realize this is an old post but I am building something similar. I was stuck at 330 @ .740 lift with the intake manifold.. Two weeks ago I had a break through and gained 60 cfm by making my own intake manifold. I tried sep runners but couldn't manage it. 4.250 bore 2.180 valve, mcsa 2.78. I used a...