Video

Glad you liked it! Kurt

So the resistor is an "as needed" operation. It increases the pull up current on the armature and is installed if the alternator light lightly glows or comes on at idle speeds. The resistor is connected to across the terminals of the bulb holder for the alternator light. I will see if we can add this to the next job we do and make video. Kurt

@@klassikats that’s great thanks. I am installing the updated alternator currently with a WOSP unit. The car is an original 67/68 911L and the original wiring to the alternator is 1 big red 1 small red 1 black and 1 brown. I don’t seem to have the blue wire. Would the small red be the blue wire? Also do we completely disconnect the external voltage regulator plug or do we retain one of the pins?

will add it to the list next time we have one out. Kurt

Thanks Kurt

Could not tell you as I did this job to long ago to remember. However, if the engine type and the cams you are using call for 0.47 mm then that is what you should set you timing too. Kurt

Did it, and it did not correct the issue. Kurt

@@klassikats can you please tell us what did?

I was never able to completely resolve the surging issue. I was able to improve substantially to the point that it only slightly surged when the engine was cold. I suspect that this car has an aftermarket program in the engine control unit and that coupled with our altitude here in flagstaff, (7000'), is causing the car to run richer than it should. I would like to have the control unit re-flashed to a stock configuration. However, the closest BMW dealer around here is 180 miles away and the issue is just not worth the time and money it would take to fully resolve the issue. Kurt

So guides in the 911 engine are good for about 100,000 miles, (160,000Kms). Typically the exhaust valves are the first to go and a set of intake valve guide can last around 150,000 to 175,000 miles. The reason for the failure is the environment that they live in. Air cooled cylinder heads run much hotter than water cooled engines. An air cooled head runs around 25o to 275 degrees F in normal operation. This means oils will tend to break down faster and parts need to be assembled looser to allow for greater expansion of dis-similar materials. Lately a lot of the heads we are seeing are being damaged by previous work. Machine shops that dont specialize in air cooled motors tend to assemble valves and guides too tight. This causes valves to seize in the guides and material transfer will often occur. I dont know about any guide lasting over 250,000 miles even in water cooled engines. Engines that dont use rocker arms like the 928, 944, and 924 models will tend to have longer lasting valve guides. This is because the rocker arm in the 911 engine places a side load on the valve stem that in turn wears against the valve guide. When the the cam lobe works directly on top of the valve the load on the valve guide is very minimal. As far as a guide material I use a Phosphor Bronze valve guide, and I pay attention to the new installation clearances and I use high quality oils in the engines I build. Kurt

@@klassikats Ok.. Thanks Kurt for your invaluable info if anyone who ask about 911 valve guides it would be you. Would adding upper cylinder lubrication say morey's a brand that's one of the best in the fuel help to lub those guides and help on the valves?

i like using upper cylinder lube especially in engines running unleaded gas. It is great for the fuel system and can help with valve seat life. However it will not help with valve guide life. Kurt

Thanks 😄 Kurt

I just dont really see any brake booster issues. Usually the biggest issue is the check valve failing. Other than that in last thirty five years I think I have only needed to replace 1 brake booster. What issues are you having? Kurt

@@klassikats Thanks for looking at this Kurt! My MC was leaking so I removed it along with the booster. Separated MC and BB and there was fluid leaked into the BB. So, replacing the MC w new. Also, trying to figure out how to deal w the wet/flooded BB. What started all this was my calipers froze --- this after rebuilding the calipers, replacing pads/rotors/ and brake lines the hard line attached to caliper and the rubber lines.

I would just drain the brake booster, flush with a little brake cleaner and put it back together. I have done this many times without any booster issues. Kurt

@@klassikats thank you Kurt for the suggestion/recommendation. Do I need to split/open up the booster shell case? Or just drain and clean thru the openings/ports? Thanks!

No do not split it open, just drain it. Kurt

We are in Flagstaff, AZ. There are huge differences between a Weber carburetor and a Zenith carburetor. Zenith carburetors are far more complex in the way the operate. The availability of tunning components for the Zenith carburetors are also a problem. Kurt

I use a glass bead/Aluminum oxide mix. Kurt

Thanks, will do! Kurt

Glad it helped Kurt

Thanks Kurt

It takes about a day and a half for this kind of job. Feel free to email us at contact@klassikats.com and we can set up a time to talk. Kurt

Yes, its possible. I see the effects of different oils on engines, and there some oils out there that are definitely dirtier than others. Kurt

JE pistons yes Kurt

If the bearing is falling apart other than the inner race then yes it is time to replace it. Kurt

Your welcome. Kurt

You can email us at contact@klassikats.com and we can set up a time to talk. Kurt

@@klassikats thanks, email sent

The valley of the piston should face the spark plug. You can also see the intake valve relief in the lump of the piston. Kurt

Thank you, Kurt. I'm rebuilding a 1975 2.7 CIS engine thanks to a few books and your videos. Thanks again

Measurement and surface condition Kurt

I am in Flagstaff, AZ you can reach us at contact@klassikats.com Kurt

Yes they do Thanks Kurt

Paul, It depends on your intensions. This set was just a little to beat up to continue on with. Right now the cost of new Mahle pistons and cylinders are about the same as having a new set of pistons made and the cylinders replated. Given the choice I will always go for new Mahle unless I am doing something custom with bore size and or compression. Kurt

Tom, So the pistons live in the most in hostile environment in the engine and the fact that they have survived a 150,000 miles is a testament to their quality. All things wear out in any engine and it is just time for these pistons and cylinders to retire. Thanks again Kurt

No they appear mechanical in nature, like something went through the cylinder. Kurt

Thanks Kurt

Thanks again! Kurt

jetting will always be unique to the engine that the carbs are being run on, the location, and the quality of the fuel being used. Running on our test engine does not confirm jetting. It does however confirm operation and adjustability of the carburetors. Kurt

I like and have been doing it our latest rebuilds. Kurt

Thanks Kurt

@dennisvogel yes, as long as it is not worn. Kurt

Dennis, I use an aluminum washer with a Nylock nut. In your car it would have been a flat washer, wave washer, and a plain nut. I do prefer the later style of fastening. Kurt

The only problem that I am hearing is that Porsche themselves are having issues finding the people with the knowledge to train new techs on the older cars. This is always the issue with the dealer networks. Once a car gets to be 5 to 10 years old it tends to fall out of the dealer network. The dealers dont tend to stock parts for cars past 5 years old and once a car hits that 60 month mark it is usually out of warranty. This usually pushes the service and repair out to the independent shops. The focus for a tech working at the dealer is always on the new technology. This coupled with higher turn overs at dealerships results in the loss of knowledge and skill sets. This is not a new issue and this has been the normal in the automotive industry forever. The big differences that I see in todays world is that the base skills are being lost, information is being corrupted, and lastly the value of the cars have increased so much. New cars today require so much less service that the basic mechanical skills are no longer trained and those skills are being lost. Simple things like mixture adjustments are no longer performed by the mechanic and instead are locked out and controlled by the engine management system. This results in new techs not having the tools or the experience that is required on the older models. With todays information super highway the amount of wrong information out there on service and repair is just out of control. I cant tell you how cars I have repaired because the owner/shop tried to fix an issue using information they found online. Lastly, now that these cars are worth so much more money, we see more and more people trying to cash in on that fact. Shops springing up with little to no experience with product line and lacking the tooling and experience to accurately repair the car. Often these shops have good intentions but just lack experience. The only problem with that is that vehicle owner pays the price of that learning curve, both financially and with the frustrations of a bad repair. Kurt

If the cam box is worn then the only option is to replace it. Kurt

Nice. Kurt

Your welcome. Kurt

thanks

I would look at fuel pressures, sounds like the control pressure may not being working correctly. Kurt

They both work just fine. I am just used to using time-serts as that is what we used when I worked at the dealer and just continued to use them in my own shop. Kurt

We are in Flagstaff, AZ Kurt

No, if the fluid was black and smelled burnt then the transmission is done and it is time for a rebuild. More than likely the filter is being clogged by debris off the clutch packs as the friction material is flaking off. Time to pull it out and go though the entire transmission Kurt

⁠​⁠@@klassikatsok thank you , is there a way to test the the clutch packs ? I took the valve body apart and it had small metal flakes and 1 kinda melted check ball inside ,can that maybe cause the trans fluid to be burnt ?

When the clutches and or bands slip in the transmission they create excess heat. This results in the transmission fluid being burnt. The burnt fluid is the symptom and not the cause. With BMW it is tough because they do not have a service schedule for the transmission. Changing the transmission oil every 25,000 miles will remove normal debris from the system and will prolong the life of the transmission. when fluids and filters are not changed, the oil flow and condition will become diminished. This in-turn can result in slow clutch application which will increase wear. Kurt

Thanks Kurt

Your welcome, Kurt

So its true that butane can work in an A/C system although there is no way that I would put it into an automotive A/C system. R600A is also not an automotive rated gas. it is used in refrigeration units and not in mobile A/C units. There are currently three types of A/C gases used in automotive applications, R12, R134A, and 1234Y. All of these gases are mildly flammable under the right conditions. However, no where near the flammability of butane. Kurt

@@klassikats And the flammability of 85 litres of premium petrol is higher than that of less than a kg of butane !

I made it Kurt

⁠@@klassikatsis it base on VW 643 stand? Edit: So this crankshaft is from other video. Sorry I got confused with order of video assembly.

No it is my own design. Kurt

@@klassikatscan I buy one from you?

its been a while since I made one for some one else. email me at contact@klassikats.com and I will get some prices on the steel and give you a price. Kurt

There is no subframe on a 911 Kurt

Thanks! Kurt

So most of the wear that i see is in the throttle shafts more than the bushings. The Teflon bushings I just always replace and dont really look at to hard. The bronze bushings I measure using a pin gauge and replace or oversize as required. Kurt

@@klassikats Dear Kurt, That's very good news (I ordered a 8.000mm pin gauge already) - thank you so much for your prompt reply. From which rocking of the pin gauge would you refrain from reusing the standard shafts? >0.1mm? Or less/more?

So the running clearance should be 0.03 - 0.05mm usually the throttle shafts will measure 7.97 to 7.99 mm and the shaft bushings will 8.00 - 8.03 mm. I will discard the throttle shafts at 7.94 mm and will replace bushings or overbore, which ever one you prefer, at 8.05 mm. It is very rare for me to be able to reuse throttle shafts. Most of them measure well below 7.90 mm in the bushing area. Kurt