I may be expecting too much from my 340. It isn't slow but still just doesn't seem as strong as I thought it would be. I have tuned and re-tuned down to about as good as I think I am able.

Here's what I have:

1969 340 block, bored .030
Speedpro Forged pistons
Scat rods
Scat crank, everything internally balanced.
Lunati Voodoo 60402 cam
Edelbrock 60179 heads with ductile adjustable rockers
Edelbrock RPM performer intake
Holley 750 vac. secondary
MP billet mech advance distributor, curved at 22 initial 38 all in.
Doug's Headers with 2 1/2 dual x pipe exhaust.
904 transmission with low low gear set and Cheetah auto / manual valve body and Hughes 2500 rpm stall TC.
3:23 Sure Grip rear
255-60-15 tires in the rear.

The car will get up and go but it doesn't roast the tires like I thought it would. Matter of fact I can't get much of a burnout using the brake. Again, maybe I am expecting too much out the 340. I guess i had my hopes up for more. I'm a bit disappointed.

Am I expecting too much? Have I done something wrong with this build?

Problem = 3:23 Sure Grip rear

Try some 3.55's or 3.91's, that'll wake it up

Was the cam degreed in? What is the compression ratio? Or the cranking psi. It should spin street tires easily with even a 3:23. What car is this in ?

As said: what cranking compression. what vehicle. 38 deg at what RPM. Degree the cam (& timing chain error). EDIT I ain't a cam guy & that cam MAY be too much

Before you give up on the engine, try some more gear and some more converter.

3.91s and a 3,000+ stall converter and watch the smoke roll.

Cam is mild I have the bb one in my near stock 383 it's a good cam with a lot of low and mid range! Are the secondary's opening?

Cam installed centerline? That's first up.

Where is the timing all in?

Hate those open chamber ede heads, wrong fricken part and why they ever made them... stupid. First thing I do when I get them is mill the chamber off.

Piston in the hole? Low static compression will hurt it, but that thing should cook the tires even on two barrels.

It's either an assembly issue or a tune up issue

I am wondering about the 3.23 gears combined with 255 15" tire (even with "low low gear set"). Also, as already asked, what car? A body, B body?

It's at 73 challenger.
The pistons do come above block deck the standard height for a 69 340. I don't recall the exact numbers.
I built the motor and lined the timing marks up for the timing chain. They were perfectly aligned. I'm not knowledgeable as far as degreeing a cam goes. I have built 4 motors and installed at least another 4 or 5 timing chains. I have always aligned the marks
Not sure how to check if the secondaries are opening. I installed a Street Avenger because I don't have a lot of expertise tuning carbs. I have rebuilt a few but I am by no means a tuner.

First thing I'd do is get the cranking compression number. That'd give you a good overview on how stout the long block is (+ maybe a leakdown check later). I've heard good things (on here) for that carb

Put a 3500 stall in it and you will be impressed.

2500 stall is not near enough.

I don't think there's a problem with the motor itself. I will check the compression but I think it's likely a gear, torque converter or tuning issue. The motor is very strong. I guess I just expected too much. I had a 2007 SRT charger and eventually felt it wasn't enough power if that gives some insight. I think my expectations might be too high. I want to be able to roast the tires at will and still have good highway manners. I'm a bit OCD....

Hard to believe the gearing is the problem. My mild 360 with 3.23 gears will roast both rear tires without using the brake as long as you stay on the gas. Torque converter is 2000 RPM stall speed.

OCD and didn't degree the cam?

I'm not familiar with that cam as far as duration @ .050, LSA etc but just lining up the dots on the gear set is a crap shoot at best with any aftermarket cam. If it is off even a few degrees especially if it is retarded, it can make a huge difference depending on the rest of the combo.

Kevin

Does it have good throttle response? Are the secondaries opening on the carb?

I'm learning as I go here. I have never done anything more than align the marks to install a timing chain. I guess I must have screwed up because I never learned to properly degree a cam....Like I said...Still learning.

By no stretch do I expect the current 340 to equal my SRT. For all I know this motor may be great and I am just expecting too much. I am trying but I seem to be well behind the curve of most here on this site. I obviously have a lot more to learn. It's great to have such a wealth of experience and knowledge to fall back on for advice.

I am 49 years old, have worked on cars most of my life and I am constantly amazed at the knowledge and expertise of others on this site. It is humbling. I do body, paint, motor, suspension, interior and recently learned to build a transmission. I am still amazed at how much I don't know. This is a great resource and I appreciate all of the advice and help.

I'm able to hear the secondaries open on every functional 4 barrel carburetor. The distinctive wail/moan is sweet music!