I run 9.5:1 static w/5# boost, alum heads and 93 octane. It will run well for you as long as the blower is spinning 10k+rpm and you do the alum heads.
Last edited by blue thunder; 10-30-2009 at 05:34 PM.
just found out my cr is 8.8 to 1 and was a gen 5 or 6 502 to start, and is now a 540. I was told to run a 871 or bigger with an intercooler to keep the air cool, and only like 4 pounds of boost and it should live...........what do yall think???
[QUOTE=302Sport;3027086]just found out my cr is 8.8 to 1 and was a gen 5 or 6 502 to start, and is now a 540. I was told to run a 871 or bigger with an intercooler to keep the air cool, and only like 4 pounds of boost and it should live...........what do yall think???[/QUOTE
To start off with a Blower motor is a Blower motor and a n/a
motor is a n/a motor from the start of your plans to build.
I find this thread interesting because that is exactly what Im into now.
First off you must remove the cranks and have a 1/4 key added 180 away from your 3 1/6 key for the blower hub. If not the pull on the small factory key will brake and more than likely is will ruin the crank snoutt before you get it shut down.
7.4 to 8.4 is a good compression to look at doing. Reverse
domb(maby 20cc) blower piston and a H-BEAM RODS for sure. You dont need to spend a ton of money on the heads because the blower is going to make the power for the head.
Edelbrock makes a nice marine head for the money.The block will be fine. Your cam needs to be for a blower app. At the least your valve springs have to be set up for the compressed air comming from the upper side. The air speed is going to be charged and will put more weight on the top side of the valve. With this you may want to step up the spring rate. The fuel system will have to be completely changed. Boost referenced carbs is a must. The Ignition system has to have a boost retard. I like to drop 1.5 deg.
per pound of boost. If you dont do this you will kill your engines.
You will fall in love the first time out but they wont last long.
Here is my port engine. I was going to install blowers on the 502s and go. Just like you are wanting to do. And over $50,000 later in parts alone I have Dart 540 Blower Motors .
I hope this helps.
4 psi of boost out of an 8-71 won't need an innercooler.
i agree it doesnt need it, but from what everybody tells me, it is nice to have.......
If you decide to run an intercooler you will need to run at least 5-6 pounds to compensate for the intercooler. At 4 pounds of boost is really nothing also, don't forget it takes hp to spin that blower.
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