Why is sbc so slow

Joined: May 20, Posts: 18, Profile Page. Oh, and what carburetor is on this, and have you checked for vacuum leaks? Joined: Sep 27, Posts: 5, Profile Page. How did you find exactly TDC? Joined: Oct 1, Posts: Profile Page. You should be able to lower your idle to the point the car dies. Terrible80 , Jun 14, Truck64 likes this. Engine man and pat59 like this. Joined: Aug 7, Posts: 3, Profile Page.

You don't need it to be in drive to check timing, I suspect you have a vacuum leak causing too fast idle speed. Dick Stevens , Jun 14, Joined: Nov 11, Posts: 15, Profile Page. Joined: Feb 3, Posts: 3, Profile Page. Joined: Feb 6, Posts: 15, Profile Page. DDDenny , Jun 14, Flatblack 31 likes this.

Joined: Jan 13, Posts: 6, Profile Page. I'm guessing vac leak also. Is the motor warmed up and the electric choke set right? Joined: Dec 26, Posts: Profile Page. Like gimpsy said.. What I thought was a vacuum leak once was actually an intake gasket that hadnt completely sealed on the intake runner I also saw you said you had no more room to rotate the distributor.

Does it crank slow regardless? Does it crank slow with plugs in and fast with plus out? Your problem could be mechanical or electrical. I'll address the electrical side since this is what I'm known for 1 You may have a bad battery. It may have voltage at no load, but with cranking load, drop below an acceptable state, approx Put a volt meter on your battery and check the voltage at the battery under cranking. Or, take it to an auto parts store and have it checked.

Your battery must be fully charged to perform a proper test. If you have a current meter, check the current draw of your starter. Current draw should be in the area of - amps. If it is above this, your engine may have mechanical issues creating excessive load on the starter. If you do not have a current meter, you can calculate current by using a DVM and the attached link. Check the voltage drop to the starter motor by placing the Pos.

The reading on the meter while cranking the engine will represent your voltage drop to the starter. Next, identify what size gauge wire you are using from your battery to your starter and it's total length. Enter all these values into the calculator on the attached link, and you can estimate your current draw enter current draw values until "your" voltage drop displays.

If you calculate out that your starter is drawing in excess of amps, your engine may be tight. If your starter is drawing less than amps, you may have a bad starter.

The above tests, if performed properly, should allow you to identify if a slow cranking issue is a mechanical, battery, starter or improper wire size issue. Last edited: Jul 16, Did I read you Installed a turbo trans behind said motor?

If so was the converter installed correctly? Chris Tobin said:. RPM's is that they are a little small but do have awesome response as stated earlier by Charlie. The stall converter will need to be in the min to a max to be optimal. I doubt that is the problem though. That combo should rip in a Z! I would reflect a little and make sure that the camshaft was degreed in properly and that you aren't a couple degrees advanced or retarded, sometimes it can happen and everything works fine, sometimes it won't work worth a crap.

Make sure your timing curve is proper for your cam and head combo also. I would put about degrees of initial in her and put the correct advance stop bushing to only add about 14 to 16 degrees through the centrifigal? I would also remove the vac. That distributor has some cool features for curving it to your liking.

Explore your options in the distributor. Your problem could be hiding under your dist. Your motor without dyno tuning should be solidly in the flywheel range of about hp, and as we all know that should be a very healthy motor for a Z! Keep digging and if you come up empty call me on the phone at work: Performance Plus, Dublin Ca. It's a little easier for my slow typing fingers to use the phone for brainstorming!!

Call me if I can help!!!! Single plane and Holley - yeah! Not necessarily the DP but the tried and true non-emissions since you have the lower stall torque converter unless you have the money to change that too.

I believe if I had to do one inexpensive thing, I would change the cam to what would work with the rest of your engine combo. Yo are experiencing the effects of parts that don't work together. Try it - you might like it - it is the least expensive route. Then you can determine realistically how much faster you want to go at what cost.

D: All of the above. The cam sounds a bit agressive for a street cam, but not that bad for an occasional driver. Also mentioned the stall speed is probably killing you a bit as the motor isn't getting into the torque curve as fast as it could, although with a light car and 3. I'm not sure how the 2. A couple of things mentioned earlier, the distributor is non vacuum,mechanical msd. Also a good friend offered a victor jr to try, If I like it I can get him a replacement.

I do want a Holley double pumper. Can you say EBAY! Also grumpy, you mentioned going with a milder hydraulic roller cam. I have a newly installed roller set up, not to savvy when it comes to roller set ups. I had springs upgraded on heads to accomadate cam.

If I swap cam do I need to go comp cams to match other components? Get a Holley with a good single plane like a Vic Jr. Privacy Policy. Log in or Sign up. Atomic Industries www. Register now to get rid of these ads! The H. Joined: May 8, Posts: 6, Profile Page. Last edited: Apr 4, Joined: Dec 27, Posts: 7, Profile Page.

Four idle mixture screws? Mine all had two. Maybe try a vacuum gauge and see if the problem kicks in at power valve 6. Play with float levels any? Joined: Sep 3, Posts: 27, Profile Page. Jalopy Joker , Apr 4, Joined: Jun 8, Posts: 10, Profile Page. Carb is a dp It has a rear metering plate just like the front. Your problem sounds like you have the wrong power valve. It is to low. Get a vacuum gauge on it and read what the vacuum is at idle.

Then get a power valve that is. Fuzzy Knight , Apr 5, Joined: Jun 19, Posts: 9, Profile Page. I was told to go two numbers below the vac reading for a stick car. Can you explain more. Joined: Nov 21, Posts: 2, Profile Page.