All the belts stayed on. :grin: Do you need to clue the gaskets to the valve covers (and to the head)? Got them on but but they did leak when it went to 12 pounds of boost (they are sheet metal covers). How much vacumm should be inside the engine? How much to to much? The catch can remained dry.
Re: vacumm pump fail have questions I use the header evacuators. They helped me a lot. Had to be a simple system because there no room left under the hood.
Re: vacumm pump fail have questions I've run mine at 12 inches of vacuum for the better part of 6 yrs, with sheet metal valve covers with cork valve cover gaskets and have never had a problem. I don't think you would want more than 12 inches of vacuum on a wet sump application . Just my .02 cents.
Blower motors might be different but most guys will tell you 10-12 is a good safe number on an N/A car. I'd be interested to learn if and how boost changes things.
Re: vacumm pump fail have questions I had a friend that used an electric vac pump from a turno Volvo on his race car. If you want will get more info on it. He was using it on a 600+ inch Chevy.
Re: vacumm pump fail have questions which model did it come from? i use to work at volvo dealers and the only pump i can remember came off of a 2000 - 2004 s40 and they will help out power brakes but thats about it.
Re: vacumm pump fail have questions Maybe the way I should have gone, but was afraid it would not be enough. ---------- Post added at 09:59 AM ---------- Previous post was at 09:51 AM ---------- Idle and light driving is fine, but when I get to 10 pounds of boost (have boost guage) it blows oil out around a few seals. It looks to be coming out the harmic balancer/front cover and the valve covers (the right side more than the left where I am pulling from). Have parts on order the hook up a vacumm guage to monitor the internal engine vacumm. Will try 12 HG. ---------- Post added at 10:18 AM ---------- Previous post was at 09:59 AM ---------- When is that? At idle or 6000 RPMs?
Re: vacumm pump fail have questions My Moroso 4-vane pulls 12" at 2000 rpm on a warm engine. I have it regulated to 14" st 7000 rpm. My gaskets are glued to the VC only.
Hi Michael, I am ignorant of the "blown engine" world. Please explain all this about using vacuum pumps on the crankcase. Do you use a compound type guage on crankcase to monitor vacuum and pressure? TexasJohn
John, I am also tring to fiqure this out. I have a compound guage for the manafold vacumm that reads both pressure and vacumm and have the parts on order to install a single action vacumm to show the internal of the engine. The set up I had did a pretty good job until I tried to run it at Bowlng Green (1/4 mile track) last fall at The GS Nationals. It did alright at a track here in Louisville (1/8 miles) and when I drove it on the street. What I had before was a set of Poston valve covers that had four 1 1/4 inch aluminum tubes that were about five inches long welde to them and at the end I had "filters" on them. They looked like something you would see on the circle-track car. My engine mechinst said it would be a good idea to install a vacumm pump. According to BDS's chart on having the boost I have it is like having 14 to one compression. At that much compression, you are going to have "blow-by'. My thinking is to get the guage close to zero at the finish line of the 1/4 mile.
Not just blown engines but a lot of high performance engines end up with extra pressure in the crankcase. Tall breathers on valve covers are a real simple solution, pcv valves have been around forever. Also found out the HP is available by reducing the oil mist in the crankcase. It seems when you start to put a motor under pressure any of those little leaks that you have lived with now become a major problem. For me part of the fix was to use crankcase evacuators http://www.summitracing.com/parts/sum-120108 The other part was to really work on doing a good job sealing the motor. Made sure everything was super clean and then used lots of the grey Permatex sealant. The Poston pan I have is a real pain to seal up but got it after the third time. Michael is pushing a few more pounds of boost than I am so he is stressing everything a little more. The Summit system is so cheap it might be worth a try. John, those of us that have blown motors often think we are ignorant about them.
Michael, You need another compound guage on the crankcase to monitor how efficient your system is operating. It will tell you how much vacuum you have at idle and how much pressure you are building under hard load with max boost. Doesn't boost pressure backseat the pcv valve? Also, even if your rings are controlling blowby effectively, remember that boost pressure is getting past at the intake valve guides when you boost it, if you have loose clearance there or some worn excessively, it will really aggravate your problem. BY THE WAY, BOWLING GREEN WAS MY HOME TOWN, Beach Bend has been there since I was a kid. TexasJohn (I got here as quick as I could) ---------- Post added at 08:07 PM ---------- Previous post was at 07:55 PM ---------- Another note: Diesel engine have always had high compression, from 14-1 up to 21.5 or so, normally high boost requires a lower compression ratio and timing in diesels. Funny that they don't have issues with that problem unless they are worn out. The older engine had a simple road draft tube of 5/8 to 3/4" diameter with a wire mesh filter on 14 litre (855 cu in) engine. My old 8.2 litre Chevy had a CR of 21.5 non turbo'd. FOOD FOR THOUGHT. TexasJohn
Hope the parts will be here before next weekend for the second guage. That is the reason for a PVC valve. To burn oil vapors and help with the crankcase pressure. I do not have one. I have a dodge "Team G" intake with Charlie Evans (no relation but live in the same state) intake adapters. Boost pressure will not travel up throught the valve guides. Blow-by is a product of compression going past the rings. In most cases diesel engines have four piston rings to compat compression blow-by. A few years ago a very good friend of mine passed away and at his showing his wife and daughter had pictures of him at Beach bend in the 60s and mid 70s and it looks almost the same. He raced and set many records at that track.
"Boost pressure will not travel up throught the valve guides. Blow-by is a product of compression going past the rings." Yessir it will, they suck oil don't they? That is the reason for the valve guide seals on most engines. TexasJohn
My thoughts also but I asked the same question to the mechinst who has been doing blower engines longer than I have been alive said that boost will not travel up through the guides.
Michael, no disrespect to your machinist, but guides and seals are always a point of inspection when checking for boost leakage on any application that pressurizes the intake manifold above atmospheric pressure. It might be worth the effort to fab a plate with a schrader valve and pressure gauge to cover the intake's carb pad, pressurize the intake tract and hunt for leakage with the valve covers off while the intake valves are closed (easiest to pull the rocker shafts). Devon
Just for conversation: On turbocharged engines, exhaust valve guides can also become an issue because backpressure induced by the turbo on the exhaust manifold almost reaches boost pressure levels. TexasJohn
Added another guage (vacumm only) and it only showed a slight vacumm when I gave it a rev. At what RPM will it maintian a vacume? Like boost does the engine/pump need to be under load to produce a vacumm?
