pulled the front clip off the Z/28

[DavidS]

After finding the coil problem, the DZ 302 was running much better.

On the dyno


After finding the coil problem, he did about 2 more trials.
Trial 1: Max Torque=332 at 4900 rpm, Max HP=354 at 5800 rpm
Trial 2: Max Torque=329 at 4900 rpm, Max HP=356 at 6400 rpm

Graph

Chart


There is still a problem though since it is not idling well. The lowest idle was 1500 rpm and it should be about 900. Norm thinks that most likely it is the carb. I might have to send it out to get checked.

[ls6monte]

Very nice David! Sounds sweet!

[DavidS]

Originally Posted by ls6monte

Very nice David! Sounds sweet!

Thanks Ron! I am hoping the idle problem is easy to find. Most of the postings I have read on completely stock DZ 302's have an idle around 900 with no problem.

[ILuvPizzaTimes10]

Damn that thing pulled pretty good!!! so whats the deal with the Idle? whats it doing? id like to know for future reference!

[DavidS]

Originally Posted by ILuvPizzaTimes10

Damn that thing pulled pretty good!!! so whats the deal with the Idle? whats it doing? id like to know for future reference!

When the idle drops below 1500 to 1700 rpm, the engine stalls out. Norm kept adjusting the idle, float level, etc but nothing worked to stop the stalling.

[frankzlt1]

Dam holley carbs they either work good or stumble on them selves. Dave you might want to check powervalves out, also what size jet are in there.

[DavidS]

Originally Posted by frankzlt1

Dam holley carbs they either work good or stumble on them selves. Dave you might want to check powervalves out, also what size jet are in there.

Hi Frank,

We started with

Jets = 72 primary and 76 secondary.
Power Valves = 6.5 primary and 8.5 secondary

And also tried:
Power Valves = 6.5 primary and 6.5 secondary

This setup should have worked perfectly since many others with the 4053 DZ carb use this. But it just keeps stalling out during a normal idle. Except for the idle problem, the engine seems to be running great.

[frankzlt1]

Yea those # look awesome, is that hp and torque were it would be for the stock motor. Did you try leaning out the carb a little meaning a little smaller jet size. How many turns are the side screws out from full close. Did you check for any vacuum leaks in the base of carb.

[frankzlt1]

I was in your neck of the woods today by lost acres rd doing pm's on generators. I see its still a big mess there.

[DavidS]

Originally Posted by frankzlt1

Yea those # look awesome, is that hp and torque were it would be for the stock motor. Did you try leaning out the carb a little meaning a little smaller jet size. How many turns are the side screws out from full close. Did you check for any vacuum leaks in the base of carb.

I believe that the numbers are typical for a stock DZ 302. We didn't try a smaller jet size and I'm not sure how many turns on the side screws but Norm was trying adjustments for about an hour and he knows the Holley carbs well. He is going to pull the carb off and we are going to take a look at in the morning. If we can't find an obvious problem, it is going to Eric Jackson at Vintage MuscleCar Parts: http://www.vintagemusclecarparts.com/