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Discussion Starter #1
hey guys, is it possible to have a 27 degree btdc timing mark :confused: ! sbc 350, and i was trying to get the timing to it's highest point only to find out that i had been running this engine way under it's mark. now it runs better than it has ever ran and saving a few more mpg's. quicker response and harder shifting, but, the melling MTC-1 cam is timed at 27 degrees btdc! is this right ???? should a cam be degreed this retard/advance ??? i have been wrong once and don't want to be wrong again!!
thanks for any info
 

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I think your a bit confused, there`s cam timing and spark timing, your post sounds as if your referring to spark timing. the cam timing is set at the crankshaft sprocket and cam sprocket, once there set they don`t move.
If you need a timing tab that allows for more degrees, I would get proforms balancer cover, it bolts on in a few minutes, has all the timing marks in degree`s on it, it won`t fling off like timing tape will, and it comes in many colors and several sizes. Since your referring to a small block chevy, they like 12 btdc initial and 36 total all in by 3000 RPM, however, you can play around with it to see what your engine likes best, the above figure is ball park.
 

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Discussion Starter #3
thanks double vision,
but how ever i'm more confused now. ok, maybe it's the spark timing that i need to be concernd about, being that it now runs better after i moved it. i may not know what the hell i'm talking about but this what i remember of what has happened so far. i had it set to TDC on the compression stroke wich read 0 degrees on the timing tab that i have on there. in order for it to crank and run i had to initialy get the timing light(standard light) move it back to 18 degrees BTDC. (this would be refering to the timing spark right) well, this is where i had left it and it has ran ok, but i felt like i was being restricted of power or something so i went back in and discoverd that at 24 degrees it runs alil better! and followed it back to 27 degrees! it cranks on a pin head, responds better at accelleration and seems to not want to drink as much gas.so my ? is, could this be a true setting ?? my cam specs are;

MTC-1 MELLING PERFORMANCE
SAE TIMING= 27 btc, 71 abc, 76 bbc, 32 atc

SAE DURATION= 278 int, 288 exh

i'm not very good with the numbers and abreviations, but seeing that it shows up in the chart makes me want ask someone who does knows. even at the exspence of my own ignorance!:(
thanks again!:)
 

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Just forget about the cam and valve timing. You are talking about spark timing.

Does your distributor have a vacuum advance can on it? If it does make sure you disconnect the vacuum line and plug it off when you time it.

Make sure your mechanical advance weights aren’t stuck or sticky. Do this by looking at the timing mark with a timing light while you rev the motor (with the vacuum advance disconnected). The timing should advance more (to around 34deg BTDC) as you rev it to around 3000rpm.

If you are still having problems you need to check if the outter ring of the balancer hasen't moved. If it has you need a new balancer.
 

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Just as Triaged said in his post, follow it.
Also remember, cam timing and spark timing have nothing to do with each other in this case. The cam timing events have to do with there lobes at the point they open and close in relation to crankshaft degrees, spark timing is a completely different thing altogether, spark timing is about getting the spark to occur at the right time to ignite the air/fuel mixture so proper combustion is produced. Tell us what distributor your using, and if you have checked the mechanical advance, and where the vacuum advance is connected and we can be of further assitance on getting your timing where it should be. The balancer cover is also a good idea because even if the outer hub of the balancer has slipped, the timing marks on the cover will still be the same since it bolts to the inner section of the balancer.
 

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Discussion Starter #6
yes it does have vacum advance and i didn't think about to check for the advance weights sticking. i'll do this and also look for the timing mark at a 3 grand rev.
thanks for the info!
 

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27 deg.

Most performance street engines have initial timing around 9,10, or 11,. Initial timing is what you read off of your "cheep timm. light" "un" off the harmonic balancer . If your car runs better at 27 degrees, something is happening to make it run there. Look at your advance springs on distributor weights. Sounds like you are not getting the 25,26,or 27or so mechanical advance you should be getting. 10 deg. + 26 deg = 36 this is where [approx.], you should be. Did you set the cam up in the engine? :confused:
 
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