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flattie
01-23-2002, 06:07 PM
Im getting ready to start my first blower motor up and was wondering if I should get the engine running on a single carb first then put the blower on everthing is new carbs. heads ,cam,ignition, ect.?
Rick

DEL51
01-23-2002, 11:21 PM
I had considered the same at one time but the time limits prevented me from doing so.My opinion is that it would be a good way to break it in.I know that some engine builders will install light weight valve springs when breaking in solid cam flat tappet motors.I was told that blower motors can have a bad ring seal if not broken in carefully,I can't remember the reason. Maybe it has to do with alot of fuel going in or the boost.I broke in my first blower motor with a 15 minute cruise at 3500 rpm then layed the wood to it.It worked but my entusiasm could have cost me.

Craig
01-24-2002, 05:05 AM
I'd check into having the motor dialed in on a dyno. I've done it with the last two blower motors I've built and it's money well spent to know the timing, jetting and everything else is right on before you hit the lake. Each time has cost about $500. Plus the added advantage of really knowing how much horsepower you have,not just a bench racing guess!!
Craig

DetroitJim
01-24-2002, 08:52 AM
Hey, Flattie, that's what I did, put it in the boat with a 4 barrel on it and ran it around for a while, checked for oil leaks, etc. Then I hung the blower on it with one carb unhooked. Even so, I melted down pistons twice for stupid reasons:
1. I ran low cost TRW pistons with chamfered tops. Absolutely no good. Too tight in the bores, top ring exposed to heat, actually bent the pistons and seized the pins.
2. I advanced the timing too far. DUMB! Keep it at 30 degrees and check the plugs after a run. Stay conservative. You may have to limit the advance curve to 18 degrees or less.
3. Get a fuel pressure gauge that you can look right at while running fast. A leanout is a disaster.
4. Most bizarre of all, the blower manifold had no water crossover and I was getting a steam pocket in one head. After 2 rebuilds, I put a jumper hose across the back of the heads. Problem solved.
5. I'm running 750 Edelbrocks with bigger jets and needles. It is crisp and clean with no black soot at all. This is great but very unforgiving of too much heat or advance. Stay fat on jets and check plugs if you lean out.
Jim

BOOSTDADDY
01-24-2002, 07:30 PM
HEY DETROIT JIM, IS IT POSSIBLE THAT THOSE STEAM POCKETS CAME FROM LACK OF WATER PRESSURE? JUST A THOUGHT!
FLATTIE-DO YOURSELF A FAVOR AND PUT IT ON A DYNO! IT'S MUCH EASIER TO FIX OIL LEAKS AND RE TORQUE HEADS AND TUNE THE ENGINE CORRECTLY. TAKE THE GUESS WORK OUT OF IT! JUST BE SURE TO RUN IT AS IT WOULD GO IN THE BOAT.
GOOD LUCK!

sgdiv7
01-25-2002, 06:06 AM
If you put in good parts and followed all the instructions on all the parts when you set it up you should have no problem. Break in the cam the way the cam co. says so then drive the living shit out of it. oh ya, start rich on fuel and low on timing then tune acordingly. Dynos are nice because you can get to everything or if your looking to squeeze all you can out of it. just my .02 cents Bill

superdave013
01-25-2002, 04:07 PM
Should you fire it up on o single carb? No
Then you would have to change manifolds.
You built a blown engine so fire that sucka up with the configuration you plan to run it with. Like others said, start fat on fuel and maybe start off with your largest pulley on top. I'm assuming that you took your time and won't have any oil leaks. Break in your cam then run it around for the day. Then I would re torque the heads and make sure the intake is tightend down (and every thing else). Run the valves and your set. Then you can start to increase your tune up.

RumRunner
01-26-2002, 08:47 AM
Flattie
Your money, and time will be much better spent breaking the engine in, and setting it up on a dyno. It's a lot easier to fix the little problems that WILL happen before you drop in your boat.