Thread: question about blower motor

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I just bought a 73 camaro, with a blown S.B. in it. my question is, is it normal on first start up, to have a big puff of gray smoke out the back. it starts easy, and doesnt smoke after its running, im new to this blower stuff, so not sure if its normal, or maybe something is wrong. a little detail. 350 cu in, 81/2 forged pistons, 671 blower with @ 10-12 lbs boost. 2 750 double pumper holleys. MSD ign, thanks T.

Blower motor , I thought you were talking about the fan motor for the heat/ac. Anyways, I would say, no, its not normal for a motor with a blower to blow "gray" smoke out the pipes on start up. Oil is blue smoke, water is white, and fuel is black.

It's probably got bad valve guides and worn out valve seals. When it sits you get some leakage down the valve stem. Upon start up you will get that gray/blue smoke.

Where is the PCV valve plumbed to? Does it smoke when you wack the loud pedal? How many miles on the engine? The more info you can give the better we can help you out.


Keith

i would say its not uncommon.

Probably caused by an over rich situation on startup. A pair of 750dps is a lot for a smallblock to digest at low revs.

my blown 454 had a pair of 750 edelbrocks and did the same thing.

Mine smokes on start up and it uses a little oil going down the road. About a quart every 1000 miles. You have a lot of carburation on yours. Mine is fuel injected with a 3 port injector, each port flows 850 cfm of air. I have 2 of the ports blocked off so it is only using 850 cfm on 388 cu. in. Mine motor is set up with a lot of clearance, I have always attributed that to the oil usage.
Ken

No PVC Valve, just breathers, no smoke at all after start up, I dont know for sure how many miles on motor, the seller said it was freshend up when the blower was put on, that was late 99, has been used as a show car for the last 10 yrs. I thought the carbs seemed big too, but it sure likes them. no bog, instant rpm, and the tires blow off the car, this is a street build with @ 10 lbs boost. thanks T.

Sounds like a great ride. I'm not a blower guy, but your issue may be as simple as worn valve seals. Sits for a while and a bit of oil comes down the valve stems. Once she starts and is warm the pressure inside the cylinders keeps the oil at bay. If it's not using more than a quart every 1,000 miles or so and there's no weird sounds (like you could hear them over a 6-71!) I'd be prone to let it be.

Regards,
Glenn

little bit of smoke is normal with the blower... has to do with the fact that when you turn the key off.. the spark stops but the carb with the blower keeps going a tiny bit.. meaning a tiny bit of unburned fuel.. with a blown motor because its chain driven with no room for timing error as the engine progresses in life you MUST keep the distributor clean and fresh wires because one cough with that carb and the blower jacked

I see a lot of blower cars puff a little smoke on the first cold start up. Mine does occasionally but it doesn't use any oil. I have 10,000 miles this year alone on it and only added 2 qts oil. I changed oil at 7k and it was a qt down. Just checked it today at 3k on this change and it is right up there. The trans uses about a qt every 2k however, figure that one out. No spots on the ground either and no mess under the car....I think driving in the rain cleans most of it however.

Most that are running right will puff a bit of black when stepped on. Mine does otherwise it is clean. After 10k this year the insides of the pipes are white cloth clean.

You can't over carb a blower like NA. All that happens with large carbs is that the throttle can get a little touchy. Then if you adjust the linkage geometry you can even dial that out. I've yet to see one that is set up right bog. I get 8 pounds of boost as quick as I can jump the throttle. 10 psi is pushing it unless you are running race gas. I run anything that comes out of the pump except diesel. Often 87 is all that is available out in the boonies when we are cruising so I have to run it. Works just fine.

I shut off the fuel pump before I shut down to prevent dripping gas inot the blower. Seems to help.

BTW, blowers are not driven by chains. They use either 1/2 in pitch timing belts or 8mm timing belts. There are others but not common on the street.

Thanks for the input guys, ive learned not to pump the carbs 4 times like the prev owner told me, and no more smoke, also changed the boost guage, and it only puts out 8 lbs max. slowly gettin the bugs worked out, and learning how to use it. and i gotta say, man i should have gotten a blower sooner. ( this is way fun ) T.

My blower motor doesn't ever smoke, but then I did not build it myself
either.