PDA

View Full Version : TR4/4A TR4A camshaft recomendation



scb10s
04-14-2013, 12:05 PM
I am nearing the end of a total rebuild of my 1967 87mm bore engine. The vehicle will be used for street use but I intend on milling/plaining the head to end up with a 10.1 CR and complement it with headers. The power valves will remain standard except for exhaust valve seat inserts and the pistons and liners are new Moss parts. THe car came with some extras which includes a pair of Weber 40mm sidedrafts, I do plan on using them but may start the engine with the standard carbs so I am not throwing in too many varialbles at the beginning. I would greatly appreciate your recommendations on cam selection, specs, manufacture or supplier and possible regrind company as well. I will tolerate a bit of a rough idle but am interested in drivability more then high RPM performance. If I should hold back a bit on the CR, I am open to your recommendations as well. I do have a good standard cam to go back with if necessary.

Thanks, Stan

1967 TR4A hardtail
Purchased summer of 2012, haven't heard it run yet.

TR3driver
04-14-2013, 01:26 PM
I can't really recommend it, since I haven't built the engine yet, but I am excited about the new street grind that Larry Young came up with. It's listed here
https://www.tildentechnologies.com/Cams/TriumphCams.html
as the "TilTech 270". As you can see, the duration is fairly mild, as Larry put it to not "destroy the wonderful low end torque that we all love with these engines". But it has quite a bit more lift than most (and faster as well, although that doesn't show in the chart). Larry feels that it should "pull well from 2000 to 6000".

Unfortunately, the last I heard, the shop that was doing regrinds for Larry is no longer interested in doing them. You might contact Joe at A.R.E. as I believe he was looking into being able to offer cams with Larry's profiles.
https://www.the-vintage-racer.com/

Sure wish I knew the specs for the "3/4 race" cam I got from Bap/Geon many years ago (like 1974). It idled with only a bit of a lope at about 1500 rpm, and would pull OK from there for casual driving. But at about 3300 rpm the engine suddenly came "on cam" and felt like two more cylinders had just kicked in! I used to embarrass 289 Mustangs on a regular basis, until the rear axle broke a tooth and I had to limp home ka-thunk ka-thunk ka-thunk.

MDCanaday
04-14-2013, 11:40 PM
It is my humble opinion that Integral cams stage 2 is a sweet street cam.I run the stage 3 and
while it makes great HP up to 6400rpm, the low end idle is notchy on the street. You may have to ship off a core
but the end result is well worth it.Steve does a fine job.
MD(mad dog)

Foura
04-15-2013, 12:16 AM
My 87mm 4A engine runs a Wade 113 grind from Wade Camshafts here in Melbourne. It is a 30-65 spec so about 275 duration. It has a good idle and great torque with reasonable fuel consumption. It is not a racing cam by any means, but it depends on what you want to do with your car. In deference to the 45 year old crankshaft (which was cracktested, polished and balanced when the engine was re-built) I rarely exceed 5000 rpm so not sure whether it would go to 6000. With the standard SUs running SM needles, it puts out enough power to beat a current MX5 in acceleration. With the original SU needles it was very lean in the midrange. You may need to keep an eye on that with the bigger capacity and a cam and headers.

Hap Waldrop
04-15-2013, 06:43 AM
I like APT cams, while I don't know much about his offerings for a TR4 engine, I like the fact that David at APT only sells nitrated regrinds and steel billets, and has the best lifters on the planet, Rockwell 60C hardness. Regardless of the grind you choose, for longevity it come down to parts' hardness level, and simply just regrinding a cam, and buying cheap lifter is a guarantee for shorter part life.

Monkeywrench
04-15-2013, 11:29 AM
FYI, Steve retired and closed up Integral Cams. Megacycle bought the cam masters, so you will have to call them.

Hap,
No one makes a steel billet for a TR4. I would avoid the new cast cam cores. Tool steel lifters are avaliable for the TR4 though, but talk to the cam grinder before running them.

Hap Waldrop
04-16-2013, 09:19 AM
FYI, Steve retired and closed up Integral Cams. Megacycle bought the cam masters, so you will have to call them.

Hap,
No one makes a steel billet for a TR4. I would avoid the new cast cam cores. Tool steel lifters are avaliable for the TR4 though, but talk to the cam grinder before running them.

Bob, I did not that. all APT regrinds are Ion nitrite hardened.