Thinking about some power upgrades - Need some cam advice - Engine Gurus help please

[nsxxtreme]

So I have the new cam in and I have a few questions about setting up the cam endplay. I followed your guide here your posted earlier in the thread:



I had to dent out the timing cover To gain some play. But when I push the cam back and forwarth I can see the timing cover deflect. Is this going to ruin my measurements? Right now I'm at .008" including the deflection seen in the timing cover with the bolts torqued. Should I change it or keep it?

I dont know how those retrofit roller cams work but the factory roller has a retaining ring to keep the cam from coming forward. Does your's have such a setup?

I am running a Milodon standard volume, high pressure pump. Are you saying my oil pressure will start to dip at high rpm? So if the lifters like their oil, then I should be running a high volume pump?

This seems to be a contentious issue among enigne builders so I'm not saying to run it one way or another. What I am saying is to closely watch your oil pressure after 4k rpms. Use a mechanical oil pressure guage and dont depend on the electrical one.

 

[Chevy305]

You should be fine, I have been running the stamped cover for years without issues. As long as you can feel some backlash before it deflects that sounds good to me, you just don't want it too tight without the deflection. I think the minimum is .004" if I remember correctly. I had to dent them too. Can you see what it is without the deflection? I really don't think it's going to deflect much because there really isn't much force at all pushing it forward. If you look at the cam the only thing that can put any force front/back is the distributor gear, and since the cam rotates clockwise (looking from the front of the engine) that will force the cam back against the block, not forward. So the amount of force pushing forward into the timing cover is going to be either close to zero or it won't even be touching it.

Edit: Are you talking about deflection when you tighten it down? Or deflection when you are moving the cam? Try to move the cam very lightyl without deflecting the cover, and make sure it has at least a few thousandths and your are fine. I just looked up the spec, .004 - .010".

Here is a pdf from comp cams about it...

http://www.compcams.com/catalog/COMP2011/pdf/COMP_Catalog_2011_408.pdf

I have been running the stamped covers in both small and big blocks, the small block for 15 years, no issues. I just dented the cover, back when I put that in there was no recommendations for shimming or anything, they just told you to dent the covers. My timing is very consistent.

It was deflecting when I pried on the cam. I tried it again earlier today and I confirmed that i have a small amount of play before the cover deflects. I guess I was prying too hard.

Anyways I got everything installed and started checking the valve geometry and it seems the roller tip contact is on the outer edge of the valve stem through the full range of motion. I guess I need some shorter pushrods, and the swap continues to wait...

Some pics:

 

[folkenheath]

Without pushrod length checkers you will have to estimate which ones you need. Or you may want to order a few different lengths and send back the ones you don't want? You'll figure it out, it's looking really good so far. That intake looks much better than the old one.

 

[Chevy305]

Without pushrod length checkers you will have to estimate which ones you need. Or you may want to order a few different lengths and send back the ones you don't want? You'll figure it out, it's looking really good so far. That intake looks much better than the old one.

I thought about the geometry and longer ones actually seem to correct my problem if I got my head right
The current pushrods are 7.29" and the heads recomend a +.100" rod so I ordered a set of 7.4" as they were the closest I could get. I probably should have ordered a pushrod length checker in addition in case these are wrong too.

I agree the new intake is damn sexy!

Pushrods will be here tomorrow

 

[folkenheath]

I thought about the geometry and longer ones actually seem to correct my problem if I got my head right
The current pushrods are 7.29" and the heads recomend a +.100" rod so I ordered a set of 7.4" as they were the closest I could get. I probably should have ordered a pushrod length checker in addition in case these are wrong too.

I agree the new intake is damn sexy!

Pushrods will be here tomorrow

It's hard to say for sure without seeing them cycle through the motion, but based on you are saying they are on the outer edge of the valve stem, that would mean they are toward the headers, and not the intake correct? Which would usually mean you want a shorter pushrod.

Also, your poly locks seam to be pretty high on the valve stem(the set screw is deep), which doesn't matter at all, but usually when the pushrod length is right they end up somewhat closer to flush with the set screw, but not always. You have to keep in mind the pivot location is below the valve stem tip, so anything getting the pivot location more perpendicular to the valve stem will make the rocker length effectively longer.

 

[Chevy305]

It's hard to say for sure without seeing them cycle through the motion, but based on you are saying they are on the outer edge of the valve stem, that would mean they are toward the headers, and not the intake correct? Which would usually mean you want a shorter pushrod.

Also, your poly locks seam to be pretty high on the valve stem(the set screw is deep), which doesn't matter at all, but usually when the pushrod length is right they end up somewhat closer to flush with the set screw, but not always. You have to keep in mind the pivot location is below the valve stem tip, so anything getting the pivot location more perpendicular to the valve stem will make the rocker length effectively longer.

None of the rocker arms are adjusted accept the #1 for the mock up purposes. And the outer edge means towards the headers.
So I guess my gut saying I needed shorter rods could very well be correct
We will find out tomorrow, if these are wrong I am going to be pissed, I can't wait to run this!

 

[Chevy305]

Its Running!

I finally got it running! I managed to track down a pushrod length checker and it measured out to 7.050". A bit shorter than I thought they'd be but the geometry is right so thats that.
I will say the cam lopes a little more at idle and has quite the bark when you get on it too I can't wipe the smile off my face!

Here's a crappy cell phone vid of it. I wish I had a better camera to get a good sound bite of it. (BTW ignore the alt belt squeal its new and needs to be readjusted)

http://s139.photobucket.com/albums/q313/Hawaiig146/?action=view&current=VID_20120518_184453.mp4

 

[nsxxtreme]

I will say the cam lopes a little more at idle and has quite the bark when you get on it too I can't wipe the smile off my face!

Mine doesn't lop, perfectly smooth at idle but I agree the vodoo cams are very good. Big smile on my face once I had my 383 running too. Told ya you'd like it. Opens up an screams nicely. I hated my truck until I built my 383 now I enjoy driving it even though I get bounced around on leaf springs.

I like your valve covers which are those?

 

[Chevy305]

Lope I guess isn't the best word, more like choppy but still steady. And ya it screems too! It pulls real hard all the way to 6000rpm

The valve covers are here: http://www.summitracing.com/parts/PRO-141-924/

 

[nsxxtreme]

Lope I guess isn't the best word, more like choppy but still steady. And ya it screems too! It pulls real hard all the way to 6000rpm

The valve covers are here: http://www.summitracing.com/parts/PRO-141-924/

You can get rid of the "choppiness" but you will have to play with the tune at idle. It's not easy, but should tune. I did mention this would be were it would be difficult to tune. Other then that yes I agree the cam rocks.

Thanks for the link