Just thought I'd share this so y'all can get a feel for it...

Doing a pair of SBC heads... Milk Truck variety.

OEM valves are worn about .0005+, useable, but the faces have already been cut once and the head margin is shrinking. Head margin is the meat above the face..... required mass to dissipate heat. Without it, the valves over-heat and warp. These aren't quite knife-edged, but they're on their way.

Guides were shot.

So I ordered new Seal Power valves, machined the guides for bronze inserts, installed the inserts and honed each guide individually to fit the SP valves.

Now I need to cut the seats.

Well... the SP valves are a bit small on the OD, so the new guides are coming in at under .34375 (11/32) and my pilots don't fit so I can't cut the seats. The cutting stones ride on a carrier, which rides on the pilot, which centers in the guide and makes the seat concentric with the valve stem/head/face.

I have SIOUX equipment, .343, .344, .345 and .346 pilots.... but not .341 or .342.

So... I order a SIOUX T341 and T342 pilot (total cost over $50) to complete the job. Now I'm losing money.... and time.

Pilots are back-ordered. Called 2 more vendors.... same story.... back-ordered.

How long?
Nobody knows, nobody cares.
So the job is put on a back burner until SIOUX gets a wake up call.

Never had a need for T341 or T342.... T343 is the standard.... SP dropped the ball on the valve OD. They are inexpensive compared to Manley, but I wouldn't put my name on them. Much less quality than OEM quality. V2143 ($8.69@) Intake, V1904 ($7.59) Exhaust. The application didn't warrant expensive valves. Milk Truck is good enough.
But now I wait...

Just thought I'd share.
This is the kind of stuff that can happen when you're waiting for your machine work to be done.

 

I'm by far an expert but will throw in my $0.02. If the other pilots are available, then cut or polish one of the pilots you now have till it fits.

Now that I said that, is pilot is the tool that goes into the guide to hold the stone at the precise location when grinding?

 

That would (possibly) solve the current problem, but render a $25 pilot useless for any other 11/32 valve job. That's not cost effective.

They are "tapered" pilots... that (yes) do go into the guide.
A .T343 starts at .3420 and gradually increases to .34304 so that it locks tightly into the guide to keep everything concentric.... you cannot just mod them. They are precision tools.

Each tool vendor has their own methodology.... once you buy into it, you are tethered to their replacement parts (to a degree).

For example, I need SIOUX tapered pilots with a 3/8 +.010 stem because my stone carriers are SIOUX. But I can buy Black & Decker replacement grinding stones as long as they are threaded for my SIOUX carriers.

 

yeah, it's that little-known fact that the tools required for precise work are VERY SPECIALIZED . . . and not always readily available . ..

 

Would be nice to have you do my machine work, Tom. At least I'd know there was a reason why the job wasn't making progress. My usual experience is to get a wall job (drop of heads or whatever; call back in a couple weeks to ask how it's going; call back in another couple weeks and ask how it's going; go over to the shop and see my parts are just sitting next to a wall).

 

[QUOTE=Tom454]That would (possibly) solve the current problem, but render a $25 pilot useless for any other 11/32 valve job. That's not cost effective.
QUOTE]

Either you pay $50 for a 341and 342 or you modify another and replace it with a new at $25. One way you spend $50, the other way you spend $25 and some time (or the cost to have it machined).

The only other thing is to take the heads to another shop who has the proper equipment; they may have had the same problem and ordered in a pilot from a previous job. Some of your decesion will be based on how soon you have to get the job out the door. The good thing about having the pilot is you never know when you're going to need it again. Could be next month or 5 years down the road.

Is there any rental place that rents equipment? It may be worth the hassel of renting another setup to complete the job.

 

Tom what is the ID of your stone carrier ? There are a number of machine companies that carry pilots in 3/8 and 7/16 . I have used Kwikway pilots with sioux carriers a few times and they work out fine . All pilots are extremely hard and must be ground on a cylindrical grinder unfortunately . Kwikway also makes an adjustable series but they are also very expensive , I have used them and found them to be very accurate .

Geo

 

Tom, do the Sioux seat grinders work the same way as the old B&D's? I used the B&D's years ago and they weren't too bad, but to be honest I don't recall sizing being a issue.
Hope your customer is understanding too.

Gary

 

Either you pay $50 for a 341and 342 or you modify another and replace it with a new at $25. One way you spend $50, the other way you spend $25 and some time (or the cost to have it machined).

I have found it to be more cost effective in the long run to invest in the .001 and .002 undersize pilots... I have them for 1/4" (Briggs & Stratton) 5/16, 9mm and 3/8 valves.... just never had a need for SBC 11/32... parts have always been on the money. I think these valves were made offshore. They are pretty crappy. (ok for a Milk Truck). The heads are not even ground.... rough cast with a serious lathe point. The stems & faces are machined well though. Otherwise, I would not even use them.

ram82fire:
The SIOUX ball-bearing stone carriers use 3/8 + .010 pilots. Yes... Kwickway and a number of others sell pilots similar to the SIOUX tapered series... but not identical. The last time a vendor substituted a non-SIOUX pilot(s), I mic'd them and found out they were way off spec. I sent them back and requested authentic SIOUX pilots.... which do cost more than the generic brand. I wouldn't think of grinding any of my pilots... you are right: they are extremely hard.


Gary... B&D systems use a different pilot OD I believe. Also... I don't think they sell a "tapered" pilot, which I prefer over a straight cut pilot.

The company offered an adjustable pilot... $50 also. But I use my pilots as "plug gages" as well... so I'm better off with buying the T341 & T342. Actually only need the .342, but if/when I extend a set, I always go .001 and .002 down. I'm sure I will use them again.... that's a given.

I have $15000 in valve equipment.... some of the stuff I didn't sell when I closed my automotive machine shop. I shouldn't have to go to a competitors shop and grovel for help. The valves should have been cut right in the first place.

 

I have the same machine. Been there, and done that.....some times you lose money to keep business......but that is what it is all about.....

 

What does "Milk Truck" mean?

 

A long long time ago... when horses hadn't yet been completely replaced by trucks... in my neighborhood in Syracuse NY... we used to get milk delivered directly to the front door by a "Milk Truck" delivery service. The vehicles were adapted for refrigerated units.... couldn't miss them from a mile away. Since there were 5 of us siblings- this was a major timesaver for the shopper of the house (mom). We consumed about 2 gallons of milk per day.

The trucks were totally useless for any other purpose.... strictly a point A to point B vehicle.... utilitarian... unworthy of the attention, care and precision we expect for our beloved Corvettes.

 

Here is what I sent the vendor...

> Tuesday, 4/5/05 10:45am EST
>
> Cheryl...
>
> Could you please inquire with SIOUX and ask them what* the expected delay
> might be?
> I can wait a few weeks, but not months.* I currently have a pair of
cylinder
> heads that are ready for me to use the T341 & T342 pilots. The job is on
> hold as a result.
>
> I use the pilots as "plug gages" as well, so an expanding pilot does not
> meet my needs.
>
> Thank You
>
> Tom


Their totally unexpected response...

Tom:

****** Cheryl is out today.* The 2 pilots you ordered will ship tomorrow,
4-6-05.* They will be drop shipped directly from the factory to you, saving both time in transit and shipping cost.

Thank you for your order, please let us know if we can be of further
service.

Sincerely,

Jon Woodward



Nice to see that some people take customer service serious.
I do believe I've found a replacement machine shop supply vendor.

 

Good to see that Jon has taken the effort to get it right to you.

Nothing POs me more then vendors who send you a letter in with your other stuff that says "QTY ordered 1, QTY shipped O, backordered"......till WHEN???? However when you ordered it over the phone they go...its on its way.

They don't even know when they are getting there own stock and seldom share it with us the customer.