Quick Valve Guide Check: Question

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hoodeng
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Re: Quick Valve Guide Check: Question

Post by hoodeng »

Sunnen tools are top of the range that's for sure. There are others that will do what you want within an accuracy that is applicable to this task.
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ProPower engines
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Re: Quick Valve Guide Check: Question

Post by ProPower engines »

skinny z wrote: Thu Jan 13, 2022 8:11 pm Well, like the title of the thread says: Quick Valve Guide Check.

I'd say from the replies that there really isn't such a thing.
While I'm confident that the guides aren't worn as I have build notes from when they were toast, they shouldn't be considering the mileage (around 8K) and the amount of effort I put into the geometry.
I'll have to break out the tools and have a thorough look.
I have to get back to the shop who did the work and see where there target was for a clearance spec.

Thanks.
If the shop that did the work was just a basic engine machine shop not saying anything bad about the guy that did the work last but I have seen many engines where the heads were just done a few 1000 miles ago be absolutely trash.

FWIW when I look at heads to be reused off a donor engine for guys on a budget the guide clearance is the critical area for valve sealing. With excess clearance the valve is trying to seat in a funnel shape cause the head can move excessively side to side.
Now you can do a decent guide job with liners and just broaching and keep the clearance down to about .001 for int.'s and .0015 on the exh. side if you have a good selection of liners with varied min finished ID size's.
Cast guide work most times guys will knurl a marginal guide and ream but the sizing don't last long maybe 8-10k miles at best and the positive seal will wear out faster and suck oil anyway shortly down the road.

Even if the geometry is bang on bad guides will make things wear faster because of the extra movement between the valve face and the seat.
Also depending on the seat widths if the intake is narrow they tend to last longer then a wider contact area of an exhaust seat.
The factory uses an interference method using a 44 or 46 degree seat and a 45 valve face so the high load point of the contact area is so narrow it will seal( thats the break in period ) but over time they mash together and get wider which is why you will see seats that are real wide on one side and not so much on the other.


Just saying if this is a resale project with min. expense to max. profit I get it and again nothing wrong with what your doing I just see alot of engines with less then stellar performance that is caused but a bad valve job.

Even the top name brands have issues with complete mass assembled units and the number 1 complaint is oil consumption and excess guide clearance.
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skinny z
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Re: Quick Valve Guide Check: Question

Post by skinny z »

These heads were done by a top end shop out of Edmonton. AMS engines.
New bronze guides. New intake valves. Good looking valve job. 5 angles. Blended throats. Pocket ported on the intake. Flowed well for a little head.

So, the intention is to not sink another nickle into them as this is the 2nd go around for these. The first valve job was a bit of a mess based on the feedback from AMS.
I took a lot of time with the refreshed head to make sure the geometry was dead nuts.
8000 miles on, that engine, despite being seriously hurt, didn't use a drop of oil.
I'm thinking at this point, I'll get deeper into measuring the guides using the tools I have. Snap gauge, micrometer. We may even have a bore gauge similar to this Sunnen dial.

DSC03756.JPG


We are a premium machine shop manufacturing facility after all. Millions invested in QA. Just not automotive orientated. But some of the tooling transfers over.
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Kevin
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Re: Quick Valve Guide Check: Question

Post by skinny z »

hoodeng wrote: Fri Jan 14, 2022 12:44 am Sunnen tools are top of the range that's for sure. There are others that will do what you want within an accuracy that is applicable to this task.
That is something I hadn't considered.
I'm going to bet we have similar dials in the shop. In fact I'm sure we do.
Thanks. I'll be talking to QA later today and show them that Sunnen dial.
Thanks again.
Kevin
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Re: Quick Valve Guide Check: Question

Post by conan383 »

Hello I have few questions. I ( stupidly) went local again to this machine shop in my town and had new guides put in my topline iron heads. the old bronze guides had side to side clearance of more than .018. He didnt tell me that he installs cast iron, and he burried an intake into head .060 thou. tlaked to him and he installed new seat. never noticing the iron guides till now. and checked the side to side clearance of .009. That seems way excessive for a brand new guide clearance. I just get the feeling this is definitely not a performance oriented shop?
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Re: Quick Valve Guide Check: Question

Post by skinny z »

Charliesauto wrote: Thu Jan 13, 2022 10:35 pm Sunnen P-310
hoodeng wrote: Fri Jan 14, 2022 12:44 am Sunnen tools are top of the range that's for sure. There are others that will do what you want within an accuracy that is applicable to this task.
skinny z wrote: Fri Jan 14, 2022 8:11 am
I'm going to bet we have similar dials in the shop. In fact I'm sure we do.
Thanks. I'll be talking to QA later today and show them that Sunnen dial.

True enough. Presto.

Mitutoyo.jpg

I'm ready to go.
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Kevin
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