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Top man Andy good you are still enjoying it. Paul Sent from my iPhone using Tapatalk
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Yes. knackered air cooled 911 motors frequently deliver 90%.
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I think I get it. Maintaining pressure for a long time is harder than creating pressure spikes that last only a fraction of a second. Therefore, it's a better indication of subtle problems. But, am I right in thinking that if an engine shows good compression this means that it can function properly (at least in the short term)?
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I didn't either but! (Still prefer the Alitalia colours)
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Look at it in another way: a compression check measures how much pressure an engine can make. a leakdown test measures the engines ability to maintain pressure. worn valve guides, valve seats, scuffed bores, missing head studs and general wear can often get missed by a standard compression check - or at least show a reasonable and consistent reading on the gauge. Every engine spec has a different compression value. A 2.7 cis engine with 8.5:1 pistons will show much higher gauge pressure than a hot rod 3.0 with a 10.5 :1 CR and hot cams with lots of overlap.
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Picked up new Audi today. What a fantastic thing. Love it. In the flesh, v similar colour to my 997, so a pleasant combo! Many thanks for advice. A good outcome from a bad and frightening thing. Sam Sent from my iPhone using Tapatalk
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Nice picture Andy, is your radiator leaking. đ
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It is definitely complementary.
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I'm confused. Could you give an example of an engine problem that fails a leakdown test but gives good compression?
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Thanks for the feedback. I have an endoscope for my iPhone so will give that a go. Iâll double check the oil level as well to hopefully eliminate one thing. The triangle of death is pretty dry, no fresh oil but I have new gaskets etc to do this anyway so if I need to do a partial drop, Iâll do these at the same time. Some crawling round under the car tomorrow. Sent from my iPhone using Tapatalk
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One of the three oil cooler to crankcase seals are another possibility.
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I have a wireless endoscope (DEPSTECH) which was quite cheap but is fantastic for this kind of diagnosis. Way better than a mirror. Couid also be too high an oil level if youâve topped up recently. It gets pushed through the breather into the air box and then finds its way out around the oil cooler. David
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Time for a top end rebuild... part 2
Phill replied to MaxDiesel's topic in Engine Build & Transplant Threads
Thanks Matt, very kind of you. I think any rebuild will be a couple of years away but I like to be prepared! -
Time for a top end rebuild... part 2
MaxDiesel replied to MaxDiesel's topic in Engine Build & Transplant Threads
Thanks Phil ! đ If you do take the plunge with your engine then you're welcome to borrow any of the Porsche specific tools I've got - looks like you're not too far away. -
964 RSRish build
PorscheApostle replied to PorscheApostle's topic in Engine Build & Transplant Threads
So for instance here are some Motorsport pistons mahle that have been machined to take advantage of the offset. The compression ratio is high on these so machining the valve pocket had little effect on the CR. Next is a set of 964 pistons which are also offset but symmetrical in the crown so flipping them is possible . The E represent Einlass or intake in German hence the orientation. Last set are 3.2 Carrera which to my surprise were also offset but cannot be flipped for obvious reasons. My point being the offset is wrongly installed by Porsche on 4,5,6 giving no advantage to that bank. DBS -
964 RSRish build
PorscheApostle replied to PorscheApostle's topic in Engine Build & Transplant Threads
Lol. I'm fully aware of the concept of the offset but my point was the irony of the offset on a single plug piston such as a 3.2 Carrera which has (if you have built one before humps for the flame swirl) it is however offset symmetrically which means the RHS bank is offset wrongly as apposed to it's lower left and upper right thrust. I have done this with Motorsport pistons with the same offset flipped them around and machined the pockets for the intake valves for the intake valve timing and overlap clearance . The concept of the offset is to reduce piston slap. The reason I haven't done this with my CP pistons is I already have them and do not wish to buy new ones. The point being Porsche did not flip them from factory. -
There is a set o Ebay that might have the right offsets for a wide bodied IB... https://www.ebay.co.uk/itm/183928712552?ul_noapp=true Mark
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911 sc rarely starts first time. Always second try
Phill replied to Jowniofownio212's topic in Ignition
Mmmmm..... I'm starting to think dodgy starter solenoid......... -
Could be a leak from the "triangle of death" and running down. Could also be the seals where the oil cooler joins the engine. You really need to do a partial engine drop to be sure or get some small mirrors and plenty of light behind the CIS to see. An endoscope might do the trick. Which ever way it goes remedy is a pain in the proverbial. Hopefully it won't be the oil cooler itself. Mega expensive nowadays. Even when I did mine 10 years ago or so it was ÂŁ400! They are not repairable. To be sure you need to take it off and pressure test it in a bowl of water.
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Fired up the old girl this morning for the first time in a while. Ran for a bit whilst doing a few other jobs and got a fair few drips righthand side front from the heat exchanger. Neighbours hopefully like the smell of burning oil... It's not a great area to get your head in but I can't see any obvious areas where the oil is running from so, as the oil cooler sits right above this area, wondered if it was a leak suspect. Car has always had a little oil smoke on this side, but this is more than usual. Any other suggestions welcomed. Cheers Kevin
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911 sc rarely starts first time. Always second try
Jowniofownio212 replied to Jowniofownio212's topic in Ignition
I have no means of testing the fuel pressure and donât know how to test the CSV. No matter if the engine is hot or cold, the car only starts on the second attempt. This is even if I try to restart it 10 seconds after shutting down. Eg, I thrash the car for 10 mins. Stop it, then try and restart it and it wonât start first time even if I keep the key held for 10-20 seconds. My starting process is try to start it for 2 seconds, then ignition off for 5 seconds then second attempt and 9/10 times it starts straight away. If if I link the fuel pump to run as mentioned above, it starts first time every time. This is where I think there is a loss of pressure for starting. its booked into the garage next week as I cannot test the fuel pressure my self so will keep you informed -
I think complimentary, details his learnings, and covers more than just the engine https://www.amazon.com/Porsche-911-Performance-Handbook-1963-1998/dp/0760331804
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No, is it complimentary to the Dempsey one or repeating the same in a different way?
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Have you got the Bruce Anderson book? Itâs not a build book specifically, however.
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Yes agreed, I was insinuating that if the owner doesnât know the oil fill method, there may be other things they may not know which are contained in the owners manual.
