I am a rookie so bear with me. I did numerous searches and none seem to answer my questions. First off what is a valve springs usually stock recommended installed height? I've read anywhere from 1.718 to 1.75 ?

I recently ported my heads. These heads (601) had been worked before with larger valves and a bowl blend. They have springs good for .510 lift, and bronze guides installed.

One thing I didn't pay attention to during dissassembly was the valve spring keepers. I did keep the valves and springs in order so they would go back on in the order they came off. I didn't pay attention to the keepers and when I went to put them back I noticed one set of 8 are +.050 offsets.


What installed height should I be aiming for here? I test fitted two valves and with
the offset one installed on the exhaust and the standard on the intake, I got an installed height of 1.75. Is this about right? The exhaust valve stems seem to stick up farther also.

I planned to reused these keepers because the heads had very low miles since I took them off for the porting.

All the exhaust valves have shims. One head has smaller size shims under the big ones. I figure they went a little deeper into those seats and had to add a few more shims.

Another rookie mistake I did was not smooth out the valve stems where the keepers made the groove prior to removing the valves. I scraped some metal out on the first few. I hope it's ok and I didn't fully ruin the guides. I saw a tool in the competition products catolog for honing out the guides. It's similar to the tool used for cylinder walls. I am considering this. Maybe I should just make sure all the metal shavings are out and use clean motor oil while assembling them.

Any thoughts or suggestions would be helpful. Thanks

Jerry

 

I am guessing 1.75 is safe since I am looking through various springs by different companies and most are 1.75. I don't know what brand they used when building these heads but the diameter is around 1.265. This seems to be an odd number and I can't find any companies with this diameter spring.

 

Reaming or honing the guides will only remove more material, creating more stem clearance. Don't do that unless you've installed replacement guides.

Clean out the guides, oil the stems, and install them. When you install the seals, protect the seal by placing one of the provided (usually) plasic caps over the stem tip to prevent scarring the seal lip.

Spring installed height is supposed to be 1.710" on most SBC heads, but I've seen a lot of variation in factory heads. Get them as close as you can with common shims and stop sweating over a few thousandths. Many times, heads are assembled with an intentionally different spring installed height (especially with aftermarket springs) to allow adequate lift without bind.

The exhausts will often look like they are installed at a different height due to machining differences to allow use of the valve rotators (yuck) on factory heads. As always, recycle the rotators and replace the height with shims as necessary. Your offset keys (keepers) are usually on the exhaust valves to reduce the effect of the thicker rotators.

Was that a "set of 8" individual keys, or a set for 8 valves?

 

as you know you should of filed the ends of the valves before you took them out. i use B&S valve guide lube, contains lead, on the stems and seats when i do a set of heads. as for your instaleld height follow the spring/cam makers specs and not a gm manual since you aren't building to gm specs any more. the installed height could be from 1.7 to 1.8 give or take depending on what you have.

 

Thanks for the tips. That was a set for 8 valves. The other set of 8 are standard.

 

Yeah, I didn't see anything about filing the ends of the valves until I read a post on here. Surprisingly, none of the head tech books I have read said anything about this. Live and learn. lol

I wish I knew what springs they used when building the heads. I could call the place out in AZ and ask them if I was really picky about it. I think I am now pretty sure they are around 1.75 from what I see. Like Vader said, I am not going to sweat it if they are off just a little bit.

 

within .020 isn't bad, within .010 is great. for me it's always a big hassel buying shims around here. if you would need shims look up k line on the web they have everything you'd ever need or want.

 

Ok, I finally got around to installing them on one head . I hope what you are saying above applies to what I see now.

I measured the installed height at 1.75 before installing each spring. The intake valve seats are ALOT higher than the exhaust seats due to the machining they did on the exhuast. I used the .050 offset keepers on the exhausts and the standard keepers on the intake to make them all 1.75 installed height.

After installing them it just doesn't look right. Should the intake valves sit up higher when looking at them? I know the seats are higher. I used the shims over again that were on the exhausts. All parts were assemblied as they came off except for the keepers, which I got mixed up. I am confused here. I would be grateful if someone can answer this or make sense of what I am talking about here.

I can take a picture if needed. Thanks

 

Posting a photo might really help us visualize what you are explaining.

 

My picture hosting service is currently screwed up and not working. I kind of answered my own question though. I found a before pic I shot of the heads and sure enough top of the installed intake spring seems to sit higher than the exhaust. I guess this is normal since they do have the correct installed height. The guys who assemblied the heads the first time are well known so I doubt they made a mistake here. I guess this is normal.

 

If you got a final net installed height of 1.75" you'll be fine.

These heads are machined with different spring pocket depths to account for the different retainer thickness. ( rotators on ex)
The difference is usually right about .105"
If the combination of your shims and +.050" retainers compensated for this, your fine.

What is the gross lift of the cam you're using?
You can get a rough idea of the coil bind height of a spring by
compressing it in a vise and measuring the compressed stack height.

Subtract this from 1.75" and allow an additional .050" to .060" clearance at full lift. this is the max gross lift the spring will handle.
The actual designed max lift for best performance and max life may be even less then this.

Also check to see that the retainer does not contact the valve guide seal at full lift. need .050" to .060" clearance here too.