Thread: 327 Ready to fire

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I don't like 1.6 rockers on a SBC. Any street or street/strip cam you buy will have been designed for 1.5 rockers. 1.6's will add considerably to the effort of the motor to cycle through and if there's one thing the valvetrain does not need, it is additional effort to operate. I have seen only 10 to 12 hp gain from going to 1.6's, a gain that would not be felt in the seat of your pants, one that would only be beneficial if you were in competition and needed an extra 10 hp to drive around your competitor.

I will strongly urge you to learn how to tune the motor by reading the spark plugs. You need to make a full power run, then go to neutral and chop the ignition, coasting to a stop. Any low rpm idling or chugging to another spot before pulling the plugs will mask what's going on in the motor under full power. If you idle the motor after the full power run, you will be reading what the motor is doing at idle, not at full power. Use either a drag strip or a lonely, safe stretch of road where you can coast to a stop at a place where you can pull and read the plugs.

These first 3 videos from youtube are very basic, but are a good introduction to spark plugs.

https://www.youtube.com/watch?v=c-mkbQ7Ner8
https://www.youtube.com/watch?v=siJx2yt1jaw
https://www.youtube.com/watch?v=saCDmyiBmb0
Detonation and Pre-Ignition
Reading spark plugs | Tuning Spark Plugs

You'll want to invest in a good plug loupe (10X) with built-in light, such as this Longacre unit.....
Longacre Racing 50884, Longacre Tools and Pit Accessories | Longacre Racing
so that you can see what's going on with the porcelain all the way up to the end of the porcelain in order to divide the porcelain into three parts and read it correctly.

I don't have this book, but I would highly recommend buying it for the tips on tuning that you may not find anywhere else. I would consider it an excellent value at 20 bucks....Otherwise, it could take you years to learn what this guy can teach you....
Spark plug reading

If you want to go fast with a 4-speed, bolt on a 750 double pumper carb.

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Originally Posted by techinspector1

Any street or street/strip cam you buy will have been designed for 1.5 rockers. 1.6's will add considerably to the effort of the motor to cycle through and if there's one thing the valvetrain does not need, it is additional effort to operate.

Where did you dream this up? Lobe lift dictates everything. If the lobe is stable, 1.6 rockers are a benefit.

Less lobe for the same lift makes more power. Read up here Why in the he!! do people buy 1.5 rockers? • Speed Talk

Originally Posted by camaro_fever68

Where did you dream this up? Lobe lift dictates everything. If the lobe is stable, 1.6 rockers are a benefit.
Less lobe for the same lift makes more power. Read up here Why in the he!! do people buy 1.5 rockers? • Speed Talk

OK Ray, I can see that I'm gonna have trouble with you on most everything I post and that you are either F-BIRD-88 or you are cozy with him. Most of these fellows who ask for help here are building a mild to moderate street motor, they're on a budget and cannot afford to replace parts regularly like a dedicated racer can. Therefore, there is no reason to build a motor for them right up against the wall at the risk of fraggin' something. If you want to use 1.6 rockers on a SBC motor and you're spending your own money, knock yourself out, but I will continue to err on the side of caution for these younguns who ask for our help. 10-12 hp is not something that a fellow would feel in the seat of his pants anyway in a street motor, and there are no time slips to compare. Get a grip.

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Originally Posted by techinspector1

OK Ray, I can see that I'm gonna have trouble with you on most everything I post and that you are either F-BIRD-88 or you are cozy with him. Most of these fellows who ask for help here are building a mild to moderate street motor, they're on a budget and cannot afford to replace parts regularly like a dedicated racer can. Therefore, there is no reason to build a motor for them right up against the wall at the risk of fraggin' something. If you want to use 1.6 rockers on a SBC motor and you're spending your own money, knock yourself out, but I will continue to err on the side of caution for these younguns who ask for our help. 10-12 hp is not something that a fellow would feel in the seat of his pants anyway in a street motor, and there are no time slips to compare. Get a grip.

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Ha, Just realized you the same person from the other thread. No wonder you think I'm "after" you. I don't know f88.

What I do know is a little better rocker ration is better than a bigger lobe any day of the week when it comes to valve train stability. I'm not looking for an argument if you can't trust cam designers.

Take care. I got my grip