View Full Version : TR6 Cam selection decision time could use your thoughts

02-20-2019, 10:13 PM
Got an Idea what I want to do but what would you do? Had my head milled, new hardened exhaust seats installed, going to do a light port job and port match the exhaust and intake manifolds.
Head came out to be 3.438" which is a bit over 9:1 compression with standard bore. I figure 9.125:1. Getting ready to send my cam to Delta cam shaft and looking at their 250 Sport cam and standard OEM lift roller rockers(146:1). My other option is to use the original Triumph cam with a step up in lift to 155:1 roller rockers. Just want a mild upgrade in horse power say around 115 to 120, good idle and reliability.

These are the specks on the Delta cam grind I'm looking at. Dur int 250 Dur exh 254, int opens 17, closes 53, exh opens 60, closes 14, cam rise .255 L/C 108 deg, Lash int & Exh .014

02-23-2019, 07:21 PM
I have a similar compression ratio and Delta cam grind in my car. It definitely makes more power than stock with no lopey idle or lack of grunt down low. I also think there were at least 3 cam grinds for TR250/6. US spec early, which was very conservative, P.I early, which was less conservative, and the last grind that was used on all cars I think, that fell in the middle, just right range, and is an upgrade if you have an earky US cam.

I will see if I can find my Delta specs.

**EDIT**. Looked it up, you are looking at the same grind as I have. Not lopey nor cammy at all. Have not dynoed my car, but have run an electronically timed quarter mile, got a second off Road and Track's period stock quarter mile time without abusing the drivetrain. Shaved head, Delta cam, lightened flywheel, sport exhaust.

02-24-2019, 02:19 PM
That is the Delta cam speck chart I have pictured. I have the Low Torque Sport 250 in my TR250 but I have at lease 10:1, 155:1 rockers, heavily lightened fly wheel and a bunch more and my mechanic says it's over 150hp. Don't want that much in the 6 and yes no lope and the idle I can get down to 700 RPM. Just want reliability with a little kick in the pants.