Valves hitting heads

You guys make it seem like once I run the engine with the cam there is no going back. I got it, you don't recommend the 400jr. Enough said. I have acknowledged this before and am doing it again. Am I still going to try the 400jr? Yes. Am I stubborn? No, but I already have it and it is in the block. Do I want to buy another cam and eat this one without even giving it a shot? No. If it is as bad as you say, I will change it out. Not the end of the world. Some things you have to experience yourself.


Do I appreciate your opinions? Yes, that is why I ask. If I hadn't already bought it and installed it I would not have bought it. I probably would have gone with the Max1 or L-100, but that isn't the case.

My original question was how to deal with the clearance issues, and that has been answered.

Ron, I can't remember what springs they are off the top of my head, but I'll check this weekend.

Again, thank you. I really do appreciate the knowledge and experience of the individuals on this forum.

Just think, the next guy asking for what cam to use in a mild street engine can be referenced here. I'll try to post back up my results if I ever get the project finished.
 
OK, lets take a look at the 400jr. There are avery few cams made for a short track race. Cam was designed back in the early 50's so the design doesn't use some of the modern technoligj. It has a very high lift rate, which is hard on lifters. Set the idle at 750/800 RPM and use a zink additive additive in the oil. For racing the spring pressure should be in the 75.85 Lb range. Cam will run in the 5000 rpm range with power. The major bennifet of the cam is max acceloraton from 2500 up. The biggest problem is lifter ware. Keep the spring pressure down to 65 lbs. I built an engine back in the early 90's with one and it ran across country 7 times, finely blew up with over 100 K on the engine. You will be pleased with the way it runs. I ran one in a stockcar for several years, lost the first one dur to lifter ware, second one lasted just fine with less spring pressure. You need a good quality lifter.
 
Those are pretty strong, you should have checked the installed height pressure, With stock valvs that's about 75 or better spring pressure, Plun the adjusters are all the way out on the liftes. However if you used chevy valves then the pressure is about right.
 
OK, sorry for the hiatus, but I am getting back on it.
1. I put a head gasket on and no hitting of the valves. I tested them and my exhaust valve is closest on the top of it by just a little bit. I forget what the measurement was, but I will end up just having it machined a little bit.

What is the ideal clearance?



2. My installed height of valve springs is 2.165" to 2.185" across all of them.
A friend measured the Isky 185G for me and at 60# was 2.032 and at 100# was 1.900, a free length of 2.356". He also had a set of Zephyr springs and measured them at 60# at 2.056 and 100# at 1.900, which had a free length of 2.405.

I am thinking that they are very close and I can stick with my IskyG185. To get the 65# of resting pressure I would need to shim it.

Is 65# max or the ideal pressure?
 
I bought them from Speedway and what they sell as stock for a flathead. I can measure again and even throw a picture up.

Here is a picture of the clay on the valves.
222937
 
Actually, the 400 jr is a piss poor cam for just about anything except a lamp stand.

"Been in the cam business 60 years"
 
put a 400jr cam in my rdst pu. have 4.44 rear grs w/columbia od linc grs. i like to just cruse around town etc. the 400jr cam was awful, was good if accelerating but jerks and bucks at lower rpm. quit driving it for a couple years, then took off the intake removed valve springs held valves up and pulled out the 400jr and put the stock 53 merc cam back in ,WOW car is a dream to drive now. OH1 anyone need a 400jr cam $100? building a 27T now w/flathead, going to use an AIRLEAK cam., valve to leak air into intake to make it lope at drive in and then close it and it runs great on road. used to take w/wiper hose off my 50 ford in 50's to get that sound, couldn't afford a hot cam.
 
No doubt.....kind'a cool to listen to a healthy-sounding idle while "posing" through the Dairy Freeze, but if it can't do the deed when called-on, then it's really not much better than a BS'r with a fake sock rolled-up in his britches. DD
 
V8COOPMAN said:
No doubt.....kind'a cool to listen to a healthy-sounding idle while "posing" through the Dairy Freeze, but if it can't do the deed when called-on, then it's really not much better than a BS'r with a fake sock rolled-up in his britches. DD
Click to expand...

Now that would take some big b---s to do that. :eek: But back to the cam. I just installed an Isky Max 1 in my mostly stock 59AB. Small lope and runs great. Just my 2 cents.
 
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