ET: Engine (Twin) Order of installing sealed valve guide components?

LoneStar

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Did you have to make up a special pilot to align the cutter to properly cut the seat? Is a suitable one available?

Russ,

I used this pilot with a Neway cutter when renewing my Black Shadow valve seats.


I also enlarged the hole in an extra upper valve guide to .375" and inserted it while cutting each seat, to help align the pilot correctly.

Dave
 

ClassicBiker

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Steven.
Thanks for the response. I would have responded sooner; however, we suffered a flood in our home from a broken water line. It will take three months or so to make repairs. :confused:

The new guides are in and reamed to just under .374". The exhaust guides lined up with the seats rather well and only needed slight lapping to seal. The intakes (inlets) are off slightly and will require cutting of the seats. Having never used valve seat cutters before, this is new territory. I looked at Neway cutters but have a question about pilots. Did you have to make up a special pilot to align the cutter to properly cut the seat? Is a suitable one available?

Thanks again.

Regards,
Russ
998cc
Russ,

I used this pilot with a Neway cutter when renewing my Black Shadow valve seats.


I also enlarged the hole in an extra upper valve guide to .375" and inserted it while cutting each seat, to help align the pilot correctly.

Dave

Dave, Russ,
Funny enough the pilot that came with my Neway cutter did not fit the Shadow's lower valve guide. The taper widens out just that bit to much before the cutter made contact. The reason I believe is the sealed valve guides extend further into the port than the standard guides. Because the sealed valve guides do not extend upward from where they are seated in the head, they are lengthened to maintain support. Anyway, I was going to order a length of drill rod to do the job. When I struck upon the idea of using a 3/8" transfer punch. I rolled the punch on my granite to make sure it wasn't bent. It measured 0.373" so I went with that. I also purchased the Neway cutting fluid, which I think helped as well. I was curious as to how many rotations it would take to clean up the seats so I marked them with a sharpie marker prior to cutting. Three out of four seats took ten full rotations until and the fourth took fifteen. I was applying light pressure as I didn't want to dig or gouge the seats and completely screw things up. Using Glover grade "B" grinding paste (medium fine) it only took 10 minutes per seat to get a nice even surface. The only thing I didn't do was what Dave did in using an upper guide. When I do my Comet I will definitely do that. I have plenty of old upper guides to sacrifice for that.
Steven
 

998cc

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Check my post above - it is #3.

Why not find a local engineering shop who do engine head rebuilds and see if they have the kit to do it for you?

Martyn,
That is a very good question. I wish there was such a firm locally. If there was suitable shop within any reasonable distance, I would take my heads to them. Many years ago, a local shop really made a mess of my heads. Had to send them off to a Vincent specialist for new seats, guides and valves. Ever since, I prefer to take it on myself.

Regards,
Russ
 

ClassicBiker

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Martyn,
That is a very good question. I wish there was such a firm locally. If there was suitable shop within any reasonable distance, I would take my heads to them. Many years ago, a local shop really made a mess of my heads. Had to send them off to a Vincent specialist for new seats, guides and valves. Ever since, I prefer to take it on myself.

Regards,
Russ
Hi Martyn,
I have to agree with Russ. I don't know what it's like where he is but if it doesn't say Chevrolet, Ford, or H-D shops don't want to know about doing head work here for the most part. When I needed new seats in my MG I had to source the seats myself and buy an over sized cutter and pay to have it ground to size for the shop, who kept the cutter. I also had to install the guides myself as they are a set height and they had no idea how to do that even after I told them and made a tool. When I needed new seats in my '72 Triumph Daytona head the shop I took it too held on to for 2 months. They kept pushing it to the back because they claimed they couldn't find seats. I think they were just scared. I finally sent it to the Cylinder Head shop in England to do it. That was before MAP Cycle in Florida could do the job. Now that I have a vertical mill at my disposal I would rather do it myself. At least if I screw it up I know who to blame and I don't have to listen to how it's someone else's fault not theirs.
That's why when you posted the article on how Maugan do the job I very much appreciated it. It told me what was important to datum off of to do the job properly.
Steven
 

Martyn Goodwin

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Non-VOC Member
Martyn,
That is a very good question. I wish there was such a firm locally. If there was suitable shop within any reasonable distance, I would take my heads to them. Many years ago, a local shop really made a mess of my heads. Had to send them off to a Vincent specialist for new seats, guides and valves. Ever since, I prefer to take it on myself.

Regards,
Russ
Even though the car/auto industry in Australia is no more (another crazy government decision) there are some remaining specialist shops still in existence. The one I use is only 10 miles from my home, its a one man operation (fortunately for me he is about 20 years younger than me so should see me out!) and he is well known in international formula one circles - all sorts of exotic engines and components are sent to him from around the world for repairs and rebuilds.

His workshop is full of amazing equipment and as clean as an operating theatre.

He did my Comet head a year or so back: new seats, new guides and gas flowed, also sorted the base of the muff as he found it was not EXACTLY 90 degrees to the bore. Turn around was less than 2 weeks - outstanding watchmaker like work. I did the strip down and reassembly. Demand for his services now so high he has shut down his web page and is reluctant to take on any new clients.

Martyn
 

greg brillus

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VOC Member
Workshops like "Fast turn around stuff" which is why not many like doing bike work as everything is different.........i don't blame them, it's just how the modern world is. Triumph heads are difficult on account of the seats having a taper on the outer so they can't fall out. These must have been cast in when the heads are made. it usually involves cutting most of the original seat out and then pressing in a new parallel seat, steal into steal as it were. I've had good shops who refuse to do it........ Even good second hand Triumph heads can be hard to find these days.
 

vibrac

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VOC Member
I have never been able to locate a suitable reamer for guides with a plain portion for location are they available or do they have to be a DIY job?
 

998cc

Active Forum User
VOC Member
I have never been able to locate a suitable reamer for guides with a plain portion for location are they available or do they have to be a DIY job?

There are a number of reamers on the market with a .3105" shank; the shank is a good enough fit in the upper guide bore. Here is an example: https://www.msdiscounttool.com/catalog/product_info.php?products_id=123575

I had my reamer sharpened on the shank end by a firm that specialized in precision tool grinding. (See photo) This allows the reamer to be drawn upward from the combustion chamber end of the lower guide while aligned by the upper guide.

IMG_1110.JPG

Regards,
Russ
 

998cc

Active Forum User
VOC Member
Dave, Russ,
Funny enough the pilot that came with my Neway cutter did not fit the Shadow's lower valve guide. The taper widens out just that bit to much before the cutter made contact. The reason I believe is the sealed valve guides extend further into the port than the standard guides. Because the sealed valve guides do not extend upward from where they are seated in the head, they are lengthened to maintain support. Anyway, I was going to order a length of drill rod to do the job. When I struck upon the idea of using a 3/8" transfer punch. I rolled the punch on my granite to make sure it wasn't bent. It measured 0.373" so I went with that. I also purchased the Neway cutting fluid, which I think helped as well. I was curious as to how many rotations it would take to clean up the seats so I marked them with a sharpie marker prior to cutting. Three out of four seats took ten full rotations until and the fourth took fifteen. I was applying light pressure as I didn't want to dig or gouge the seats and completely screw things up. Using Glover grade "B" grinding paste (medium fine) it only took 10 minutes per seat to get a nice even surface. The only thing I didn't do was what Dave did in using an upper guide. When I do my Comet I will definitely do that. I have plenty of old upper guides to sacrifice for that.
Steven

Steven.
I have decided to order a Neway cutter. What size is best? Is the 1-3/4" correct for the intake (inlet) seat, and if so, will it also cut the smaller exhaust seat? Given that my guides are reamed under .374", I will try the .373" tapered pilot first.

Thanks.
Russ
 
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