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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
I need 0.06" Shims to get an 1.70" installed height. But with the shim there isn't any guide on the head which will keep the Valve Spring in place. What Do you think, will the Valve Dance?
Thx
Danny Head \"wall" Guide No head \"wall" Guide with shim
There's a bunch of different ones of these with various diameters. Measure your guides, springs, etc. to figure out the right ones for your setup.
Yes i found those Locators, but for 1,254" Springs i can only find one shim with .120".....those are made to eliminate the Valve Rotator. There aren't any with .015 .030 .060 or something like that. The 4690-16 are those which will fit..... Last one in the List
Here i wrote the install height on the head
Last edited by Locherle; Jun 14, 2022 at 05:35 PM.
Install the locators on all the springs then use a different height keeper to get back to the install height.
Thx, i have also seen those positive and negative height keepers. But not @ Comp Cams Catalog. I also could use 0.050 lockers, but i can't find some with 7° only with 10°.
What about keeping the 1,74" height and just have lower Spring Pressure?
My heads have a real variation of valves, keepers, lash caps and locators. BBC is a bit different than SBC engines.
My exhaust valves are still the stock 1.88 diameter but use a smaller valve stem. The rotators on the exhaust valves have been removed so that larger valve springs could be installed. The exhaust valves use the typical square cut lock groove and I use 10* locks.
The intake valves on the other hand are huge. I use a 2.300: diameter valve head and to help reduce valve weight, I'm using 8mm stems. These special valves use a rounded lock groove to reduce stress on what would be corners of a square cut groove. Intakes are also 10* locks. All the valves also use titanium retainers to reduce valve weight. I would love to have titanium intake valves to reduce weight but at $100+ per valve, it was just way out of my budget at the time.
I installed shaft rockers and larger diameter pushrods and in order to get the proper valve train geometry, the intake valves needed lash caps to gain a little more stem height. With the corrected geometry of shaft rockers, a few of the pushrod passages through the heads needed to be modified for more clearance because of the larger diameter pushrods.
I bought the heads used for a good price as they already had some massive porting done to them. When you look into the intake ports, you can see head bolt sleeves going through the passages. Since the heads still needed some work, they got a new valve grind and new guides to compensate for the smaller valves stems. The spring pockets were all machined to the same height so that setting the spring install height didn't need a huge variation of shims.
In the end, if I pull the heads off the car and put them on the table, the 2 heads are worth around $5000. Making HP isn't cheap. Good machine work and being precise on tolerances will pay off in the end.
The only damage I've done to these heads was a broken valve spring (outside of a triple spring) and I caught it before it dropped a valve. With around 0.800" lift on the valves, there isn't very much room for error. With the triple springs I have no room for valve seals however this is not a high mileage engine. It doesn't run long enough to worry about oil leakage down the stem.
