HI folks, I plan on running my 6-71 blower on my 364 nailhead. The engine is a low mileage, 10:1 compression stocker. Since the engine is in great shape, i dont want to tear it down and change the pistons, etc. My plan is to run the blower at around 4 pounds of boost with a cam ground to allow more duration on the exhaust. I am not drag racing this car or anything like that but I would like to get a mild performance boost with the blower without detonating the motor. Anyone have any experience doing this?
Well at least you are not asking about a camshaft that has a rough idle. A lot of the fellas are gouing to give you different advice. But here is mine, I would not huff one without running either the block or the heads O-Ringed. The engine is a low mile engine? I wonder how well your rings are holding? You get zero blowby? I'm going to guess that with 10:1 even with 4 pounds you are going to make some pretty good cylinder pressure. This is not advice just thoughts and enough to get the experts started.
The engine has less than 20k on it. The guy who bought the car originally wrapped it around a tree and kept the motor for a future hot rod. I turned it over once a month (by hand) and oiled everything up. I took it apart and everything was beautiful and shiny. I plan on putting a mils supercharge cam and I could pull the heads off at that time to put in O-ring gaskets if necessary.
Just trying to get by as cheap as humanly possible with this car, plus im going completely old school. Im using all pre-1965 equipment. The suspension im using is from a 1948 f-1, so I wont be able to use much power anyway. The stock motor is rated at 300 horse, so I would like to keep it around there after I put on the blower. Surely there is someone who has cobbed a blower on a stocker and ran it for awhile? Oh yeah, I was alos told that the bottom end of a nailhead is bulletproof, but i should put in some stronger connecting rod bolts.
10 to 1 is way high for for a boost application. (maybe not in a latemodel Vette, but that is WAY diffrent.) Is there any way you can swap heads to something with more chamber cc? I would feel way better at 9.0 or less, particularly with a cast piston and iron heads, but I would feel even better at 8.0 If it were me, I would spend the money on a set of pistons that would get you in the 8 to 8.5 range, then you could run 6#s or so with out wondering if this is the time when you have to stop and pick up parts. O-rings are good insurance over 10#s or so, depending on your combination, but not manditory at your level. These days, Cometic gaskets can take the kind of pressures that you used to have to O ring for. I have a bazillion miles on mine at 10#s with no O rings and over the counter head gaskets. Hit the search for lots of good blower threads, but the basics are get your compression down to 8 or so, keep it about 6#s and mind your timing and air/fuel mixture. She will be a trouble free driver and make huge power that will make all your Chevvie buddys cry. Good luck, -Abone.
Im making an intake right now. Im using valve springs for the burst plates for that authentic old school look. I agree that ideally 8 to 1 compression would be the way to go, but pistons for this engine would run me about $700 and then I might as well bore it, replace the pins and rings at the same time. That would cost me some big $'s. I would rather take my chances, if I blow it, then ill rebuild it!