Edelbrock Head & YellaTerra rockers

[1scram]

For the record YellaTerra 1.7 roller rockers will not work with the Edelbrock head right out of the box.

Ok that being said, Here is what I have going on.... The YellaTerra rocker 0.3860" pedestals are not long enough to keep the rocker form sitting on the improved beefier bosses of the Edelbrock Head. I have found that if I put a 0.050" shim under the pedestals then the rocker will clear; however this changes the zero play on the pushrods. I am trying to figure out if just going to a 0.050" longer pushrod is enough or do I need to go longer than that?

I could really use some assistance from someone who know valve train geometry very well, and can help me figure out how long of a push rod I should be running.

Or, if I should even be considering this solution?

Thanks

[jsawduste]

Only way to be sure is to measure the length you need.

http://www.summitracing.com/search/part ... %20checker

Stock PR`s are in the 9.6- area so choose a tool that will give you the range your anticipating +/-

[jeepxj3]

Can you grind the beefier pedestal for clearance?

[1scram]

I had thought about grinding the head, but the way the bosses are setup you would really need to put it back into and machine ( that I do not have ) to get them uniform and looking right.

I emailed Yella Terra, and they said shimming the rocker as long as I got the pushrod length right should work just fine; so, I ordered a the Comp Cams tool and we will see what happens.

I will also check with 505 and see what they would charge to machine the bosses for me.

[nicpaige]

Where are you located? Any machine shop should be able to shave some off as long as you can give them a dimension to work to.

[SilverXJ]

Grind the pedestal? For valve cover clearance?

Your are missing the point of where the rockers are located to begin with. Grinding the pedestal will throw off the rocker arm geometry. Sure you could use shorter push rods on the cam shaft side, but what are you going to do for the incorrect geometry on the valve side? Nothing, because to correct it you would have to raise the rockers. Keep in mind you would have to remove 1/2" to 3/8" from the pedestals to clear a stock valve cover with roller rockers that need the extra clearance.

You would be making a mess of the geometry just to save yourself form using a spacer of extending the stock cover. Bad idea all around.

[jeepxj3]

Not grind the pedestals shorter. Clearance the edge of the pedestal for rocker clearance when the rocker rocks. Not about valve cover clearance.

[SilverXJ]

The Yellas should have a spacer that allows the rocker to clear the head. Would you have a pic of the interference?

If you are talking about just grinding the side of the pedestals a bit than than should be fine provided the rockers are installed correctly. I wouldn't have a machine shop do it. Too costly and it is not a real precision job that you need a machine shop to do it. If you have access to a die grinder it shouldn't take too long to do it. Once done, tak ethe head apart and clean it. Then re assemble.

[1scram]

Here is a picture of the problem

[jsawduste]

This (That) was my intepatation of your issue. The pedestal would have to be radius cut (scalloped) or the whole rocker raised by your .050.

[jeepxj3]

I wonder if Harland Sharp Roller Rockers will have the same clearance/interference issue on the Edelbrock head?

[SilverXJ]

I don't see a problem removing that little bit of material from the pedestal. It also looks like it is already bolted to the block so you would need a new head gasket. Or try the shim and check the valve to rocket pattern. But then you would have to get longer pushrods.

I wonder if Harland Sharp Roller Rockers will have the same clearance/interference issue on the Edelbrock head?

They wouldn't. They clear the stock pedestal completely. You can see the bottom of the spacer in this pic. May be better pics in my build thread.

[1scram]

We I got the nerve up to fix this problem myself, and it was really pretty easy.




Problem solved.

[SilverXJ]

That will work!