Hot Rods Valves romancing pistons, problem solved

A small block in stock configuration should be a free-wheeling engine (no piston-valve interfearance) however lift on the cam and piston changes will affect this

 

vtx1800 any NEWS / progress...?

 

That's why I like clay you roll it 20 degrees before to 20 degrees after and you get the closest spot.

 

Clay went out with hi-****on shoes , an indicator is the only way to go so you where it is the closest with out guessing

DND

 

I do measure the clay with a depth mike.

 

Some guys get it, some guys, well....

 

^^^^^"well...." that depends if one care's at what degree is close.

 

and there's more than one way....
by using an old valve cut off as a pointer to center, and using an appropriate
valve to scribe the outer ring.... and on and on and on...

 

Well, as Paul Harvey said, here is the "rest of the story". I am not sure how many times folks posted that the SBC is an non interference engine, that should have given me clue as to what the problem is. The cam was not a high lift unit, not much different than the stock cam. The long and short is the piston was not made for the 2.02 valves. It was/is an old design (I've had 'em since before 1985), I took them out of a 327 in a 62 Bel Air hard top that I parted out. The first picture shows the piston after I used my home made cut to flycut the pistons. I found that I won't get a day job making that tool The second picture is of the Lindy tool that I ultimately used. It does an nice job of flycutting as you can see in the third picture. I will have to go in and clean up the "chatter" that the cutter made. Note, now I have cut deeper into the piston that I needed, I have more clearance than I need which will drop the compression ratio and maybe that's not so bad with today's gas. I hope I didn't cut so deeply into the piston as to cause myself problems later on.
Thanks especially to D.N.D. for taking time on the phone to attempt to educate me. It's hard for me to believe that he as well as many other well versed individuals will take the time to help this old guy out. It turned out that what I viewed as a complex problem was not. Now if my ****y rotator cuff will let me, maybe I can get the car running before the snow flies!!!

 

Hi Marv

Thanks for the kind words just p***ing along a few tips I learned from the ' School of hard knocks ' in the racing game

DND

 

yea!!! to DND for helping out....

 

Thanks 'J' Dude

 

Those pistons "were't made for 2.02 valves"? Those pistons came on all the high performance 327 engines with 2.02 valves. Maybe the cam is the issue with it's lift. The factory cams did't have anywhere near the lift of many aftermarket cams. My 327 with 461X heads, and the exact same pistons, has Manley 2.05 intake valves, and NO issues so far. I see aftermarket roller lifters; what lift is the cam? Good you seem to have arrived at the solution to your problem. I am Butch/56sedandelivery.

 

I felt the same way as you that bigger valves than 1.94 have been around for a long time. I guess no one told the pistons Here is the cam card, we are not talking a really high performance rumpty rump cam.

 

The other issue could be the heads were surfaced a bunch; I still see the ID letters/numbers on the block pad, so the block has't been decked. My mechanical lift cam is't much more than your hydraulic, so your photos have me a little worried. I see your "setup" head, to do the valve reliefs, are 882's, and probably have't been cut. What about the heads you're running? What about your rocker arm ratio? Stock 1.5, or have they been swapped to 1.6? That will change the lift. I am Butch/56sedandelivery.

 

That's a pretty tight lobe center cam are you running advanced?

 

The cam is installed straight up, if I remember correctly the heads are 041, I don't have the rest of the casting number (300 miles from home)and have no idea if the heads have been surfaced, the rockers are 1.5 Harland Sharps, in a 90's Hot Rod Magazine article on heads they were touted to be good heads but were rare. I've had the heads and Pistons since the early 80's


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I really hate to admit what the REAL problem was, it was operator error. After replacing the distributor, manifold and carburetor I decided I had better check the cam. I pulled the front clip, dropped the pan and pulled off the front cover. I had installed a Cloyes adjustable timing set, but.......didn't read, nor look it over very carefully, the cam was off about 30 degrees, THIS TIME, I really did install it "straight up", maybe guys like me shouldn't get anything with "adjustments" I re***embled it all, took it for a spin, nailed the loud pedal and it went right to the 5500 RPM cutoff in the Petronix III distributor, problem solved. I guess I was just an idiot. The only up side is I have serviceable parts for another SBC build, this time in a 53 Studebaker Starlight coupe.

 

Don't feel bad, everyone here has made errors, some are man enough to admit them, others not so much. Me I admit to two, both ex wifes! Believe me your error was cheaper.
thanks for posting the final results, I will admit to learning some things in this thread.

 

At least your car didn't blow up.

 

It was a long adventure but you learned a lot from it. I learned a lot just by looking on.

 

so did you cut all the pistons before you discovered and re-did the timing? just curious. and also, thanks for sharing the real issue, it may help someone down the road.

 

We have all made mistakes like this. Glad you figured it out and posted the final outcome, my first instinct was that the cam was installed off. That's why I
(and others)suggested checking the cam timing in my first response. So apparently when the cam was degreed initially someone made an error? 30 degrees is a bunch! That would be like 2 teeth off. That's WAY more than the typical 3 option crank gear allows for. Look at the bright side, you have all kinds of piston to valve clearance now....

 

Yep, I cut the pistons before actually checking the cam, I SHOULD have used a little logic, the intake/carb/distributor worked fine on the engine before I pulled it apart and changed cams and had head work done, and after all of the h***le I have an oil leak that I didn't have before, but at least I can get in the car and drive it

 

Man I'm glad you found it.

You didn't ask for it but here is my opinion. First off EVERYONE makes mistakes so that just is what it is and always will be. But the biggest problem here is not checking the cam timing in the SEA of responses about cam timing. Every one of them was met with "the cam is straight up" or the expert friend checked it.

 

Someone should start a thread (show us or tell us all about your mistakes ) and I will tell you about the 8,465 million mistakes i've made...lol