BFreeZ28

iTrader: (1)

Car made a measily 290 Hp last week at the dyno and got worse with every run. This week I took the cats off and ataped it this time while on the dyno.It did make 10 more Hp and did gain 1-2 hp on each pull. The atap readings looked great, 02's, timing, some KR (1.2-3.9).
Im at the point where im gonna pull the timing cover back off and make sure the dots are lined up on the sprockets. Im positive they are, the car wouldnt run this good if they werent right??? I have an atap file if anyone would like to see it.

GrannySShifting

iTrader: (10)

Have you check your TPS reading make sure you get 4.5 volts and the blades 90 degrees from shut? Throttle cable adjusted right?

No misfires runs smooth?

BFreeZ28

iTrader: (1)

OK, the timing cover is off, the cam sprocket dot is at the top and NOT THE BOTTOM!!!!!! Well it ran pretty good for being 180 degrees out! :doh:

Beast96Z

iTrader: (21)

Are you sure the #1 piston is at TDC? At a given point I believe the dot will be 180 degrees out. I think if your car had been 180 degrees out, you would have bent all your valves.

Jabroni

That's what I was thinking. It wouldn't have run for long. Mine was a tooth off at one time and I would have sworn (along with the other three guys who inspected the dots before we bolted it up) that they were lined up. Sometimes they move when you reassemble. It happens. My car only gained 10 foot pounds but lost 10 RWHP. Took it apart, lined them up and up the numbers went. Keep turning the engine and check them out again.

BFreeZ28

iTrader: (1)

The left side valve cover is off, left front spark plug is out (this is #1 cyl right?). The engine was turned over until compression blew my finger out of the spark plug hole, both valves are closed and the dot on the crankshaft gear is at the top. I can feel the top of the piston with a smal screwdriver inserted in the spark plug hole. As far as I know that TDC. When I say left I mean drivers side.

DaleMX

iTrader: (4)

The cam is at a 2:1 ratio with the crank. Another 180 and the piston will be at TDC again and the cam will be lined up.

Beast96Z

iTrader: (21)

#1 is on the drivers side, front cylinder.

DaleMX

iTrader: (4)

Oops, not 180, another 360 degrees to bring them dot to dot

Jabroni

Your first post said "cam sprocket dot" and the last one refers to the crankshaft dot. Make sure that the cam dot is at 6:00 and the crank dot is at 12:00. That's where they need to be for TDC on #1.

SSactionLs1

what does TDC have to do with lining the dots up?

if u need to be at TDC..then i did my cam wrong..and im one luck sob that im racing all day and havent had a prob

(looking at it again..do u mean..when the piston #1 is tdc then the crank and cam should be lined up at this position?)

BFreeZ28

iTrader: (1)

Its back togethor and runs strong now! Dad came over and bailed me out (hes done that for me for the last 17 years automotively!) Im not sure where it was before, probably a tooth off, but it sure feels right now! What have I learned from this? If oil touches it, LET SOMEONE ELSE INSTALL IT!

Smoke_Ford

You have it backwards. You see, the crank turns twice for every one revolution of the cam. So the correct statement would be: The crank is at a 2:1 ratio with the cam.

DaleMX

iTrader: (4)

Oops, Hell I get my left and right mixed up! Glad he got himself fixed up tho.

Jabroni

That was my first guess. It happened to me and it's happened to a lot of others, too. One tooth will make wonders for power!! Nice to hear it's all straightened out. If the valve timing is off just that much, you'll lose a ton. I've seen it first-hand. Lined the dots up and BAM!! 40 more RWHP just like that.

FWIW, to do the cam, the engine doesn't need to be TDC on #1 as long as you mark the cam gear before you take it off the cam dowel and reinstall it in the exact same position as it was when you took it off and the crank doesn't move. Lining up the dots just gives more reference, that's all.