valve grinding
Moderator: Team
Re: valve grinding
Ok so here the deal. I said it was .009 on the wiggle with a dial indicator which half is .0045. larger than what you would want. so I mic it and came up valve of .3412 the bottom of guide is an acceptable .3436 clearance of .0024 BUT the top of guide measures .3456 20 thou dif for a clearance of.0044 DOUBLE. the other ones are in an acceptable range for having new guides installed. You got the brunt of my anger yesterday , as I just discovered yet another goof on behalf of that shop.were all human and make mistakes , I'm the one that is responsible for the blueprinting . I'll have it corrected. I just wanted other peoples feed back BEFORE I go down there. I dont build engines for a living but I do know how to. I dont have head machining tools, (would like em but dont have LOTS of money laying around) but I do know the sbc . Not trying to rag on anyone or say I know more than the machinist. The valves are what came with the pro topline heads, nothing fancy just stainless steel , hardened tip. Thats what I know. from what Ive read oem used chrome plated valves with the cast iron guides. If everyone is in agreement that the cast iron are just fine then sure I'll buy it
Re: valve grinding
Frankly, imo...... the wiggle test isn’t accurate enough to determine the guide clearance.
Even the split ball gauge and a mic don’t really give you the full “picture” of how straight the guide is along with the sizing.
I’d be lost without my sunnen gauge.
Sometimes the guide has a bulge near the top, but is straight and on size otherwise.
That’s harder to pick up on without the gauge.
Ask what the shop is using to determine the guide sizing/clearance.
It’s entirely possible they don’t have a real accurate way of measuring it.
Even the split ball gauge and a mic don’t really give you the full “picture” of how straight the guide is along with the sizing.
I’d be lost without my sunnen gauge.
Sometimes the guide has a bulge near the top, but is straight and on size otherwise.
That’s harder to pick up on without the gauge.
Ask what the shop is using to determine the guide sizing/clearance.
It’s entirely possible they don’t have a real accurate way of measuring it.
Somewhat handy with a die grinder.
Re: valve grinding
snap gauge and micrometer, and yes it wiggles alot. Its the only one like it , its the same one the valve was sunk in. maybe he was tired IDK. still iron guides with stainless steel valve like to gall themselves little welds. I will ask if they are some sort of a powder coated guide acceptable to use stainless valves.
Re: valve grinding
There's really only one solution if you’re not happy with the quality/sizing of the job...... along with the iron guides.
About the only thing I use iron guides in anymore are stock replacements for an OE application on late model stuff....... which in itself is a pretty rare occurrence.
Performance oriented SBC heads?
Yeh....... I’m using bronze.
About the only thing I use iron guides in anymore are stock replacements for an OE application on late model stuff....... which in itself is a pretty rare occurrence.
Performance oriented SBC heads?
Yeh....... I’m using bronze.
Somewhat handy with a die grinder.