Cutting Valve Seats, How to Rebuild a Porsche 911Air-Cooled Cylinder Head Lesson 5

Рет қаралды 10,390

Күн бұрын

This is lesson 5 of 8 on rebuilding an air-cooled Porsche 911T cylinder head.
In this lesson, we look at cutting the valve seats. Firstly you need to determine if there is room left to cut the seat. Next, we show you how to hand-cut the three angled seats and how to test the seat with the valve. What to do if the margin does not land where you need, and lastly, double-check the valve depth.
Join us in this lesson to learn all you ever wanted to know about Cutting Valve Seats in Porsche 911 Air-Cooled Cylinder heads.
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Пікірлер: 34

@henningbuld6891 9 ай бұрын

I think I am not alone here. I love the way you train and how you talk. You saved me a lot of money in doing the things by myself. I must say thank you very very much. You helped to take away my fear to get on this engine and to overhaul it! Thanks to your wife to for these accurate screening! All in all I am very happy with that education school. Its not available anywhere! You are the guide in the fog of forums etc. And you know what you are doing! Thank you so much ! I am happy that you are there! You taught me a lot! Many thanks!

@klassikats 9 ай бұрын

Glad to have been able to help. Thanks Kurt

@henningbuld6891 9 ай бұрын

Thanks!

@klassikats 9 ай бұрын

Thanks Kurt

@brunosarubi4359 3 жыл бұрын

excelente!!!!

@klassikats 3 жыл бұрын

Thank you.

@robertengholm6659 3 жыл бұрын

The new exhaust valve looks good. What brand did you use?

@klassikats 3 жыл бұрын

There are two brands that i like for valves, TRW and Intervalves. Both brands are good quality and rarely have i ever had any problems with them. Unlike some other brands out there. Thanks for watching

@TimeLapsesBaudet 2 жыл бұрын

donde podria obtener las herramientas para hacer los asientos? saldus y como siempre gracias por el video!!

@klassikats 2 жыл бұрын

Seat cutting tools are available from a number of places. Neway cutters can be purchased directly from the company here, www.newaymfg.com/cutters There are other suppliers out there that offer lots of different systems. Goodson.com is a good source as well. Thanks and good luck Kurt

@nevenmacewan1869 2 жыл бұрын

I noticed in the 72, 73 Porsche Tech Spec book that the contact width (1.5mm) is drawn as a measurement 45 degrees to the valve face which would make the actual measurement across the face 2.1mm, Is this correct or am I interpreting the tech spec drawing to literally? thanks

@klassikats 2 жыл бұрын

Neven, Yes you are taking the drawing as if it is a to scale design drawing. The seat width is 1.5 mm and the tech book sketch is just a representation of that. Thanks for watching Kurt

@nevenmacewan1869 2 жыл бұрын

@@klassikats Hi Kurt just to clear I'm not taking the drawing to be scale but the angle at which the measurement is taken What grit hones do you use for the 9 & 13mm thanks

@klassikats 2 жыл бұрын

@@nevenmacewan1869 Neven, I understand, but the dimension of the seat width is still 1.5 mm. I use a 240 grit ball hone on both the valve guide internals and on the 13 mm guide bore. They are different types of hones, however. One is designed for aluminum and one is designed for red metals.

@nevenmacewan1869 2 жыл бұрын

@@klassikats Thanks Kurt. So I'm assuming Silicon Carbide for the 13mm and Aluminium Oxide for the 9mm, one last question, i've seen recommendations to drill the guide before removing it (I'm, assuming a 10mm drill), from what you show this doesn't seem necessary, your thoughts/experiences?

@khizerhusain5237 3 жыл бұрын

Sir please tell me about margin in valve and how we check correctly

@klassikats 3 жыл бұрын

Hello Khizer. The margin is from the face of the valve to the beginning of the seat angle. We take a close look at the margins when deciding to replace a valve or not. We cover more about the margin in the 2nd lesson kzfaq.info/get/bejne/m5lynbBeu6zHg5c.html 15:52 we measure the margins Thanks for watching.

@robertengholm6659 3 жыл бұрын

Is your preference to use the original sodium filled valves or solid type? Not many choices for sodium filled valves.

@klassikats 3 жыл бұрын

The purpose of sodium filled valves is to help keep the valve cool. With that said on turbo applications and really high compression engines i prefer to use sodium filled valves. On general stock engines with a customer that is looking to save some money then i have had good success with non sodium valves.

@thinkerdoit 3 жыл бұрын

47.5mm +.6 is this a universal measurement for valve play on all air-cooled 911 heads? Where does one look up these specs?

@thinkerdoit 3 жыл бұрын

Im reading on Neway’s site a 45 deg valve surface can be cut at 46deg? Can’t be right unless theres another application im not familiar with. Any idea? Do each of those cutters cover only a single angle or multiple? Can u adjust them by 1deg somehow? How many seat cuts can you do before they wear?

@klassikats 3 жыл бұрын

@@thinkerdoit The 47.5 mm dimension is good for up to the 1977 2.7L engines. From 1978 the dimension changed to 46.00 mm +/- 0.3, this dimension was also applied to the 3.0L turbo models from 1975-77. All of these specifications are available in the factory service manuals. We have an extensive library that covers from 1955 - 1994 models covering all Porsche models in that time period.

@klassikats 3 жыл бұрын

@@thinkerdoit That is something unique to Neway's thinking. I have spoken extensively with the engineer at Neway about the theory behind it. What they say is that the 46-degree angle causes a knife-edge type of seal and that the valve will somewhat deflect into the seat under spring and compression pressure from the engine. I have used the 46-degree angle without any issues in the past.

@KG72 3 жыл бұрын

Do you work on vw type 4 heads?

@klassikats 3 жыл бұрын

Sure, The 914 models use the type 4 VW engine and we have rebuilt many of the type 4 heads over the years. What do you need?

@MM-lo7ey 3 жыл бұрын

hai

@klassikats 3 жыл бұрын

yes

@sumanmondalsuman7635 3 жыл бұрын

Valve cutting model number ?

@klassikats 3 жыл бұрын

The cutters we use in this lesson are Neway cutters. You have to match the valve guide with the pilot rod and the cutting angle heads. So 9mm valve guide pilot in the 911 and 30 °, 45°, and 60° cutting angles. We have moved on to a three-angle cutting system that cuts them all at once on the milling machine. I will have to post a video of this way as it is a great time saver and super repeatable once you have set up the first valve seat. Thanks for watching, Klassik ATS

@nevenmacewan1869 2 жыл бұрын

@@klassikats Hi Kurt, any reason for 60° not 75° (as per the specs)?

@klassikats 2 жыл бұрын

@@nevenmacewan1869 Neven, no real reason other than Neway has some unique thinking on approach and exit angles. When I'm using my production cutter I use a 3D insert that cuts all three angles at once. With that one, I'm running 30/45/75 degrees. We have some videos coming out on that tool pretty soon. Although it is an expensive setup, the tooling is about $1000 just for the cutters. Then you will need a mill or head and valve machine, a custom fixture to hold the heads in place, valve guide pilots, and finally a driver adaptor that will drive the seat cutter. If you have a mill already figure about $2000 to get started with a profile set up.