Valve springs help

[1969GTS]

You guys must be getting sick of me. OK, here is my newest dumb question. I just pulled my intake as it had an oil leak so I'm already halfway there. This car has changed hands several times but I tracked down the guy who bought it from the guy who built the motor. I can no longer get ahold of him but he did say way back in the day the dart did run around 12 flat. He also said it was a huge cam and thought it was a 509 purple shaft. He said the builder told him to change the valve springs if he was going to drive it on the street as they were heavy and would wipe the cam. Here is what I know for sure, the car runs very well, Its a hydraulic cam that is purple between the lobes, the valve springs are double springs with dampers between them. I know you can change the springs with the heads on but have heard its a pain. I can try and take some pictures if it helps. My questions are:

1) Is the 509 the largest hydraulic cam?

2) Should I change the springs now that I'm this far into the motor?

3) What should I put in for springs on a mostly street but odd weekend track car?

4) Is it possible to tell what the cam is for sure without pulling it out?

Thanks a ton

I know I ask a lot of engine questions and am a pain in the arse.

Dave

 

[1969GTS]

They are not great pic's and probably not helpful but you never know. I cant see any numbers on the cam just purple paint. Two springs and a damper per valve. I'm worried about wiping the cam as it seems heavy for mostly street use.

 

[Rapid340]

If you are really worried about it take one of the springs off and measure the pressure at the closed height and the open height. And post the results or PM me.

another good check would be to remove the lifters (one at a time so they go back in the same location) and verify that they are not concave on the lifter face or worn in only one spot. There should be a slight crown of about .001. You will need a good straight edge like a machinist's scale to check it because the crown is so small. I usually put two lifter faces together and hold them up to a light, but its easy to get them mixed up. If just two lifters get returned to the wrong lifter bores you will almost certainly wipe the cam

If there are no concave lifter faces or other issues, I would just use a good oil and/or additive, set the idle at 1000 rpm instead of 600 (The intention is to keep the engine form running any length of time at a real low rpm because not much oil is splashed on the lobes at real low speed) and go have fun with it.

 

[68383GTS]

509 lift is not really a huge cam.I would just pull the cam and springs and go with a more modern cam.That away you know what you have.Comp Cams has a great tech line.Just remember the biggest cam you can get is NOT the best thing for a engine. Jim

 

[1969GTS]

A couple of local hot rodders stopped by today while I was working away in the garage and had a peek. The both had the same opinion that the car had miles on it and runs very well. The cam had a good wear pattern and don't fix what is not broken. I think I'll stick with a good high zinc oil like royal purple and have fun with it.

Thanks for all the input.

 

[dusterdon]

if it aint broke, don't fix it!