Custom 8BA valveguides

flatheadmurre

flatheadmurre

Well-known member
Im going to tool up the lathe and make some valveguides with undersized stems.
And while at it i thought of making some with a longer valvespringseat and some with oversized outer diameter.
Any special or odd ones you guys need while am tooled up ?
 
flatheadmurre said:
Im going to tool up the lathe and make some valveguides with undersized stems.
And while at it i thought of making some with a longer valvespringseat and some with oversized outer diameter.
Any special or odd ones you guys need while am tooled up ?
Click to expand...

Try making some intake guides that smooth the flow by filling in the top of the guide on a slant. This would fill in the gap left by the recession of the air flow with the stock guide. This may require an anti rotational measure, such as pinning the side of the guide.

Karl
 
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flatheadmurre said:
Im going to tool up the lathe and make some valveguides with undersized stems.
And while at it i thought of making some with a longer valvespringseat and some with oversized outer diameter.
Any special or odd ones you guys need while am tooled up ?
Click to expand...

Hi "murre", just curious, what size stems are you thinking??

First, if you mean 5/16" this is already a very simple chore to accomplish? Been doing this procedure for years now (not a bunch, reasonably expensive). It's as simple as installing 16 NEW guides (.437" O.D. x .312") in a Chevy head. Just one step gets you to the 5/16" size, and these new smaller guides are already (spiral) bronze-lined, just need to be fitted to the new valves!

I have 2 builds out I can recall today with these inside, both on a B&M blown platform.

Second, the "longer spring seat" I would have to consider non-issue here. This is MY own opinion ONLY. Never had a single build to this very day needed attention in this area!

Third, I would NEVER even consider making any Flathead guide a press-fit in the block. It defeats the original design and has also NEVER been an issue here?? I have knurled them for a handful of customers in the recent past, again a non-issue here!

One more item, what material would you be planning on using if from scratch?

(Add) With respect to any add'l flow improvement (mentioned above) I can't possibly see ANY guide-work even being measurable? If you simply use valves with stepped-down necks you will pick up about 4 CFM more through the unit, both IN & OUT! A 5/16" stem would act the same here.

Other than everything above, go for it.

Thanks, Gary in N.Y.

P.S. Just a tip with respect to the OEM guides (and all the aftermarkets I've dealt with), also not sure how many Flathead guys are aware of this, but they are chamfered on the leading edge. This aids with the installation. On a side note, pressed or not, I would want the (guide) retainer to still be used for location purposes and safety if pressed.
 
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It´s a customer order for metric sized stems, what they are going to achieve is not something im going to argue about...they are serious builders so some thought is behind it for sure.
What i get from this is that they pay me to tool up the CNC lathe for this job and i can let it run a few extra pieces.
Not going for pressfit outer diameter just to compensate for worn guidebores.
Then im going to machine my own guides ready for liners.
 
flatheadmurre: Thanks for taking the time and energy to make those guides.
Just curious as to what type of material you will use.
My stock guides seem like some type of cast iron.
 
Cast iron if your aiming for stock if going the bronzeliner route a more machineable steel is prefered for faster turning.
 
I would think that a 5/16 stem would be good - along with maybe a .100 to .120 longer spring seat. This would reduce the need for multiple shims when running the SBC length valves (which a lot of us do run).

Also, maybe a .0005 to .001 larger diameter for a tighter fit in the guide bore. Would need to test with a few blocks to see if there is a 'optimal' oversize.

Steel guides with bronze liners would be a good thing - with an optional seal.

Lastly - both an intake and exhaust version - so that you have the larger surface area for heat transfer in the exhaust ones. (Like Henry did)
 
GOSFAST said:
Hi "murre", just curious, what size stems are you thinking??

First, if you mean 5/16" this is already a very simple chore to accomplish? Been doing this procedure for years now (not a bunch, reasonably expensive). It's as simple as installing 16 NEW guides (.437" O.D. x .312") in a Chevy head. Just one step gets you to the 5/16" size, and these new smaller guides are already (spiral) bronze-lined, just need to be fitted to the new valves!

I have 2 builds out I can recall today with these inside, both on a B&M blown platform.

Second, the "longer spring seat" I would have to consider non-issue here. This is MY own opinion ONLY. Never had a single build to this very day needed attention in this area!

Third, I would NEVER even consider making any Flathead guide a press-fit in the block. It defeats the original design and has also NEVER been an issue here?? I have knurled them for a handful of customers in the recent past, again a non-issue here!

One more item, what material would you be planning on using if from scratch?

(Add) With respect to any add'l flow improvement (mentioned above) I can't possibly see ANY guide-work even being measurable? If you simply use valves with stepped-down necks you will pick up about 4 CFM more through the unit, both IN & OUT! A 5/16" stem would act the same here.

Other than everything above, go for it.

Thanks, Gary in N.Y.

P.S. Just a tip with respect to the OEM guides (and all the aftermarkets I've dealt with), also not sure how many Flathead guys are aware of this, but they are chamfered on the leading edge. This aids with the installation. On a side note, pressed or not, I would want the (guide) retainer to still be used for location purposes and safety if pressed.
Click to expand...

What retainer and lock combination do you use?

R
 
Bored&Stroked said:
I would think that a 5/16 stem would be good - along with maybe a .100 to .120 longer spring seat. This would reduce the need for multiple shims when running the SBC length valves (which a lot of us do run).

Also, maybe a .0005 to .001 larger diameter for a tighter fit in the guide bore. Would need to test with a few blocks to see if there is a 'optimal' oversize.

Steel guides with bronze liners would be a good thing - with an optional seal.

Lastly - both an intake and exhaust version - so that you have the larger surface area for heat transfer in the exhaust ones. (Like Henry did)
Click to expand...

5/16" chevy ex valves are not cheap. And I don't think you would see a hp increase on a dyno. Do one up and report back. Its only money.The guides need only be cast no value in steel when lined the machining cost will be high.The greater number of replacement guides are cast.

R
 
Cast is for the guides to work non lined if going for liners from start production speed is main thing so going for a steel tube suitable for turning.
Don´t think anyone is casting the guides one by one anymore, they are made from a cast iron bar in a CNC lathe.
 
Ronnie said:
5/16" chevy ex valves are not cheap. And I don't think you would see a hp increase on a dyno. Do one up and report back. Its only money.The guides need only be cast no value in steel when lined the machining cost will be high.The greater number of replacement guides are cast.

R
Click to expand...

Good point on cost - might as well go 11/32 and if somebody desires a bit more flow, they step up to the 'Pro Flow' type profiles (under the head). This keeps the costs down for everybody else.

I think the best solution would probably be a steel guide with a bronze liner, with a PC seal option for the intakes and a nice 'slot' for the valve bar.

Might also want to make the 'seal groove' on the intakes take a standard o-ring (if it was even necessary with a bit tighter fitment??? - I have my doubts on that).
 
Ronnie said:
What retainer and lock combination do you use?

R
Click to expand...

Hi Ron, I assume you mean the valve locks/retainers??

Almost every build we've been involved in hasn't had a single spring height issue at all. Almost all use the standard 4.820" (nominal) valve length. Most times the Chev valve at 4.920" (nominal) also works with the pieces listed below here.

By using the various valve locks available (-.050" / Std / +.050), Comp Cams (chromemoly) 7* retainers, AND lash caps we can just about cover every needed installed height measurement. I believe we even have the lash caps that add either .060" or .080", depending on brand? If NONE of this works, we solve it by the method below in the P.S. here.

Thanks, Gary in N.Y.

P.S. (This is very important) Let me add this also, with respect to needing a very specific O/A valve length to accomplish the build where all the pieces I mentioned above will NOT fit in the end, we can simply order ANY valve head diameter along WITH the required stem length for the build, and THEN have the keeper-grooves in ANY location we choose. Example, on a custom (Ferrea) valve if (for whatever reason) we needed a +200" longer valve (not even a +.100") we could still put the locks back at the stock OEM Flathead position. This means you could use a "stock-length" valve spring WITH a +.200" longer valve length! We can request the lock grooves "down", .100" , .200", .300", etc., wherever they are needed. This method is NOT really for a limited-budget build though!
 
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HI Gary
Are u using the stock retainer that uses 11/32 locks,on the 5/16" valve with 5/16" locks. Am, i to assume there is no different retainer required when moving to the 5/16" stem and 5/16" locks?

R
 
I was aiming for a good quality normal budget guide as an end product...youre talking custom valves and stuff that is way out of normal peoples budget.
What seal are you prefering ?...lets think available and on budget...
Have to make the intake guide a bit different to have the seals and make it work with the valvebar.
 
Ronnie said:
HI Gary
Are u using the stock retainer that uses 11/32 locks,on the 5/16" valve with 5/16" locks. Am, i to assume there is no different retainer required when moving to the 5/16" stem and 5/16" locks?
R
Click to expand...
Hi Ron, no, that won't work. Haven't looked into a 5/16" retainer setup so far, haven't actually needed one! I'm sure there's some out there??

flatheadmurre said:
I was aiming for a good quality normal budget guide as an end product...youre talking custom valves and stuff that is way out of normal peoples budget.
What seal are you prefering ?...lets think available and on budget...
Have to make the intake guide a bit different to have the seals and make it work with the valvebar.
Click to expand...
Hi "murre", not seeing how that project is going to "fit-in" as a budget piece??

We suppy the "Viton" stem seals (we're not talking metric stems here, I rarely work with any metric sizes), I leave that to my son!

I have never used that valve-bar for disassembly OR assembly, never. I don't even own one. But the part about the seal not working with that tool is correct. I have shipped bronze guides out recently where I was asked not to cut the tops for the .500" stem seal, have no issue with this, customer's choice! We recommend these "positive" type seals only for the intakes also!

With the custom valves this is what I posted above, it's not going "fly" on any tight budget build. I agree 100% on this! So far, I haven't found it necessary at all to go this route anyway.

With respect to the guides, for us to get down to the .312" stems, there are more options available. We have 1-pc bronze (.312" x .437") which would go inside the OEM guides, 1-pc steel outer (.312" x .437") with the spiraled bronze liner already in place, also go into the OEM's. With the spring register issue aside, you could always use a .502" O.D. (cast replacement) guide with an existing .312" I.D. We keep everything I've listed here on the shelf or have access to these sizes.

Thanks, Gary in N.Y.

P.S. Had a very good friend (high end business owner) long ago told me to keep everything in life simple, so far so good. I have NONE of the spring height issues many up here have, for us the entire spring hgt/valve length issue is a "non-issue"!!
 
Hi Gary
In your posts then you haven't done up a Flathead with 5/16" valves and corresponding valve hardware with stock spring dimensions for 5/16".
I was aware the stock items won't work I just asked the question to clear the air."LOL"
R
 
Ronnie said:
Hi Gary
In your posts then you haven't done up a Flathead with 5/16" valves and corresponding valve hardware with stock spring dimensions for 5/16".
I was aware the stock items won't work I just asked the question to clear the air."LOL"
R
Click to expand...

Correct Ron, never did a 5/16" stem on the Flathead so far. Have none on the horizon either.

There is no way a 5/16" stem is going to pass any more CFM than the 11/32" (stepped-down neck) valve, not on this platform anyway! Will on others but not the Flathead.

One more item on the locks/retainers, when using a 10* degree lock setup the retainers are the same (basically) and remain, whether using with 5/16, 11/32", or 3/8" stems. But this is only true with the 10* stuff.

Thanks, Gary in N.Y.

P.S. With all the "small" foreign components in the arena I would not stay with domestic sizes, would immediately jump to "very-small" (metric) AND use some radial locks!
 
After reading this thread, I'd like to ask: Just what do you think you will gain by doing this? Are you planning at running at Bonneville?
 
I made some .001 and .002 oversizeds outsde dia.. guides a few years back to accommodate the loose guides in the guide bores, worked ok , it was a matttter of cut to fit on the o.d guides, had to do something , knurling worked ok , but the o.s guides worked better , I tried the copper /chrome plating it done ok on some ,but the oversized o.d., done real well to get a better center fit over knurling. I still keep some .002 O,D guides on hand just in case I find an odd sized guide bore from time to time, all I can say is GO FOR IT! then send me a few to keep if I find a sloppy bore so I can cut to fit as needed. thanks ,
Fordestes,
 
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