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Camshaft Questions

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Palmer

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So I'm getting down to the bare block on the 3, and I just pulled the camshaft. After pulling it, I realized that I have a couple of questions.

First, how can I really tell if I should replace it? It looks O.K., although there are some scuff-like markings near the tops of the lobes.

Second, if I replace it, is it worth getting a performance cam? I have no intention of using the car for anything other than street driving, but more power is always nice.

Thanks for your thoughts.
 
I replaced my cam with a mild street cam from British northwest I belive that it is the BP 290 gives the motor a little more power you can use the stock valve springs also. When the car is ideling it sure has a nice sound to it.
Dan
 
It's a slippery slope once you start engine mods. I think that you would gain quite a bit just by milling the head about 0.080". Of course, first measure the head to see if it's been milled before. The original head thickness is 3.330".

Since it would be best to put hardened valve seats in the exhaust valves, while it's at the machinist, milling the head wouldn't add much to the cost. It's the best bang for the bucks.

You can also have your cam reground by British Frame & Engine. Of course, then you may be into valve springs and other stuff. You might also have to go to shorter push rods when milling the head, but talk to Ken Gillanders a BF&E and he'll tell you if you have to when doing a head mill without a cam change.

Just realize, that whenever you change something, other things are affected and you may have to change some other parts to make it all work together.

Then of course, there are the 87mm piston and liner kits...
 
The most cost effective route IMHO is to have the cam re-conditioned.I have had good luck with Steve at Integral Cams.If you have lifters he can re-face them if they are not too far gone.If the cam doesnt check out good to grind then pop for a replacement.....
Dont mill the head(too much) on a tr3, they make LESS power and need premium gas to do it(the chamber is all wrong).Invest in good porting&un-shroud the valves,especially if you put in the big ones.....(pinto intakes are a near drop in)
MD(mad dog)
 
I have 180,000 miles on the original camshaft in my 1958 TR3A. I drive quite a bit (100,000 in the past 18 summers). Some say I have a heavy foot and I consider this camshaft to have no issues. Nor with the original bearings for the camshaft.
 
To check your old cam, get a cheap dial indicator (Enco frequently has a kit with indicator and magnetic base for under $20) and measure the lift at each lobe. You can compare the measured values to the specs; but usually just comparing all the intakes together and all the exhausts together is enough. If the cam is worn, some lobes will be worse than others. The cam in TS39781LO when it was wrecked had about .100" less lift on #2 exhaust than #1; I didn't bother checking the rest.

IMO, a mild cam in combination with a modest increase in compression ratio (head milling) and improved exhaust really wakes the motor up. If you do have the head milled, be sure to radius all the edges. The Competition Preparation manual has patterns to follow. "Unshrouding" the intake is more problematic as that area is also the sealing surface for the stock headgasket. You can't do much without having to use a modified gasket, cut the liner, etc.

I did a TR3A motor years ago with a "3/4 race" cam from Bap-Geon; sure do wish I'd saved the specifications for that cam! It idled a little rough around 1100 rpm; basically just sounded like it needed a tune-up. Pulled about like stock from there up to maybe 3500 rpm; then it suddenly felt like two more cylinders! Pulled like a rocket from there out to about 5500 (where the valves started to float anyway). Flip the OD switch at about 5000 in 2nd gear, and the front end would come up again! I used to regularly embarrass 289 Mustangs (until the rear end broke). Besides the cam, it just had 87mm liners and a tubular header (both cheap from Warshawsky's); and TR4A exhaust valves and valve springs. Didn't mill the head or anything. Just the 87mm liners bump the compression ratio up over stock.

The stock rocker adjustment should have enough range to cover .080" off the head without shorter pushrods. However, if your old pushrods are the 5/16" variant then I would replace them anyway. They flex enough to cost some power.

IMO the later exhaust valves (and special conversion guides) are worthwhile as well; if you're already overhauling the head. They leave more room in the port for the exhaust gases to get by.

Larry Young (no relation) said he was thinking about doing a 'street' cam for the TRactor motors, but wasn't sure there was enough interest. If you are interested, you might let him know. He has designed a camshaft for vintage racing that seems to be quite successful on the track, but is too hot for the street (peak power around 6000 rpm). Here's a user report from Tony Drews:
https://www.team.net/mharc/archives/html/fot/2007-05/msg00330.html
 
TR3driver said:
(Enco frequently has a kit with indicator and magnetic base for under $20)
Click to expand...
Well, maybe they don't do that any more. But this
0645007A-11.jpg

https://www.use-enco.com/CGI/INSRIT?PARTPG=INSRAR2&PMAKA=605-4080&PMPXNO=1645544
plus this
0658003-11.jpg

https://www.use-enco.com/CGI/INSRIT?PMAKA=625-0340
comes pretty close.
 
Thanks for the suggestions. I think I'll probably go with the performance cam from British Northwest. The car has the 87mm line set from a long-ago rebuild. The combination of the cam and the bigger pistons should provide plenty of grunt for road work.
 
Nobody has brought up the cam set-up where you dial in the exact timing with a degree wheel.Suffice to say get an adjustable sprocket and a good mechanic to help,he will bring his GOOD dial indicator and have your cam sharp in a few minutes.This helps your ignition to be spot on latter...
My tr4 got the stage 3 road cam from Integral.Idle is rough,but power and response was what I wanted. The dyno showed the power falling off at 6800,but 155hp isnt too bad on regular gas...
We recently built a tr2,and it got the stage2.I would recommend this for most street motors.It did not get a dyno run, but it makes way more than the 90 hp the old lump sported originally.
MD(mad dog)
 
get new lifters or have yours re-ground for that new cam. Break it in properly or you can ruin it in a couple of minutes.
Rob
 
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