whistling question

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bb489ss

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Ok, so I finally got the Dart/383 on the road today. Seems to run ok. I did run into a few issues though. 1) Under full throttle, at about 3500RPM I frequently here a whistling noise that lasts a few seconds. Almost sounds like a loose belt. I checked all the belts and they are nice and tight with about 3/4" "give". It is definately coming form the front half of the car. It starts out loud, and then diminishes and goes away. The power seems down. Second thing is the car has a Dana 60 with 4.10 rear. "Supposedly" rebuilt with all new parts, clutches, etc.... I've done several small burnouts with the car in drive and it leaves two black tire marks. Done a few starting in 2nd gear, and noticed only right rear tire left a mark (like a peg-leg burnout). Put it in drive and did one more and again, two back tire marks! I don't understand. I jacked up the car and put it in neutral and turned the left wheel and the right wheel turned in the same direction like it should. Former owner stated that he only had about 100 miles on the tranny (rebuilt 727 with Transgo shift kit) and the rear. My combo is listed in a recent post. I guess I though this car/motor would have a little more "umph" to it. I really don't think it is liking the single plain and 650 Demon that much, big stumble off the line, but that is just my opinion. Timing is set at 36. Even though vac advance is connected, it pretty much stays at 36 from idle to 2500 rpm, maybe advances a couple of degrees. I'm trying to stay patient and tune this motor correctly, but right now when in the car I just hope no punk in a 5.0 pulls up next to me!!!! Please tell me where to start to get things on track! (sorry for all of the info, but today was my first day that I could really spend some time with the car and drive it for a while.)
 
sounds like a vacuum leak... that demon 650 should have a tech document somewhere that says which port is PCV, which is for vacuum advance/distributor, which is for accessories (to be capped off unless you have vacuum actuated hood scoop, headlights, etc)

good luck
 
That's alot of info to deal with at one time....lol.
Quickly on the peg-leg in 2nd only is mystery to me, maybe just a fluke.
As far as the noise if the belt has been run loose and glazed it wont matter how tight it is now it can still squeal. Another thought on the noise is what type fan are you running. If by chance it's pump driven and has a clutch i've seen those make a similar noise when trying to disengage at higher rpm.
Tuning wise it's gonna be timing first, carb second. Remove and cap the vacuum advance for now until you get your base timing and curve straighted out. Please post again the timing with no vac hooked up at idle please.
 
It is a lot of info, I know. Thanks for all the input so far. Thats a good thought on the belts that I never thought of. They do feel a bit "shiny" when I checked them out

"It is doubtful you would get any different feeling in the seat of your pants if you changed to a RPM Performer intake."-IQ52

Really? I thought the RPM would help down low since it seems these 383s do not make a whole lot of torque down there. So maybe keep the Street Dom and go with 750 DP with a 4-hole spacer instead?

I don't get home from work until 8pm today, so Ill check timing then and post. It is interesting that I looked through some of the archives on timing here and nobody recommended using the manifold vacuum for vac advance, where with the chevy's, all the ones I've own ran much better and cooler hooked to manifold vacuum, as well as all my friends that had them (street-car wise) Whats different about MOPAR motors where this is not true? Just trying to learn. Thanks
 
It is interesting that I looked through some of the archives on timing here and nobody recommended using the manifold vacuum for vac advance, where with the chevy's, all the ones I've own ran much better and cooler hooked to manifold vacuum, as well as all my friends that had them (street-car wise) Whats different about MOPAR motors where this is not true? Just trying to learn. Thanks[/QUOTE]

I always did too. Most were close to stock and anything more then that i just went mech. adv. only. But i always felt normal drivability was much better that way. Been quite a while, but iirc some of the manufacturers put a vac. delay valve in line to soften any spike down in timing when you first hit the throttle.
 
bb489ss said:
It is a lot of info, I know. Thanks for all the input so far. Thats a good thought on the belts that I never thought of. They do feel a bit "shiny" when I checked them out

"It is doubtful you would get any different feeling in the seat of your pants if you changed to a RPM Performer intake."-IQ52

Really? I thought the RPM would help down low since it seems these 383s do not make a whole lot of torque down there. So maybe keep the Street Dom and go with 750 DP with a 4-hole spacer instead?

I don't get home from work until 8pm today, so Ill check timing then and post. It is interesting that I looked through some of the archives on timing here and nobody recommended using the manifold vacuum for vac advance, where with the chevy's, all the ones I've own ran much better and cooler hooked to manifold vacuum, as well as all my friends that had them (street-car wise) Whats different about MOPAR motors where this is not true? Just trying to learn. Thanks
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Naw, I thought it might be a good idea to read the dyno test I posted, that compare the two intakes (and others), to see if you thought the differences between them would make it worth buying the new manifold.
 
I'll be waiting on your no vac timing numbers, but i will add a few thoughts. I know you want to up the power at some point but the combination you have right now is pretty well thought out. With that said, to get the most out of what you have now........As far as timing there are alot of opinions here, member crackedback likes to put as much initial in as it will take and not surge and still start and then limit the total. That is a sound thoery and something you can work with, but for now just to get it running pretty well based on approx. 9to1 comp, the cam, intake, converter and rear gear you have i would recommened around 14-16 initial and about 40 total on the timing. This is just a general starting point for now. As far as the carb goes it's a little small but can be made to run well with what you have. Would leave 10-15 hp on the table at peak power but that can be addressed down the road. A change to a lighter secondary opening spring would probably help.
You spoke in another thread that you would like about 450 hp. and that is certainly doable, but your gonna have to change alot of the combo to get there. I would optimize what you have first then consider what it would take to get to that point.
 
What all do you think I would need to change to get to 450 hp? I have the money for whatever upgrades I need so that won't be an issue. Also I wasn't able to check timing last night because I got home late from work and was too tired to go out to the garage (plus my new 4 mos old son needed attention!!) I will try today though.
 
bb489ss said:
What all do you think I would need to change to get to 450 hp? I have the money for whatever upgrades I need so that won't be an issue. Also I wasn't able to check timing last night because I got home late from work and was too tired to go out to the garage (plus my new 4 mos old son needed attention!!) I will try today though.
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Take your time, family and work first:smile:.
Just my opinion on a upgrade to 450hp would be.....A little more compression (possible piston change), head work or upgraded heads (there are members here much more up to date on the current offerings that could make a recommendation), cam and valvetrain upgrades and a larger carb. Whatever combo you end up with will surely dictate more torque converter also. I'll look around and see if there are any recent build articles or threads that might have a combo that would help with some of the questions.

I did find this. A little hard to read 2 pgs. of that small print. Westech's dyno has always seemed to me a little friendly with the numbers, but it's still a impressive build. http://www.moparmusclemagazine.com/techarticles/mopp_0209_383_engine_restore/index.html
 
Just my two cents besides what has already been said. I would look for a vacuum leak. And make sure the kickdown linkage is adjusted right. I also think a bigger carb would help.
 
OldmanRick said:
Take your time, family and work first:smile:.
Just my opinion on a upgrade to 450hp would be.....A little more compression (possible piston change), head work or upgraded heads (there are members here much more up to date on the current offerings that could make a recommendation), cam and valvetrain upgrades and a larger carb. Whatever combo you end up with will surely dictate more torque converter also. I'll look around and see if there are any recent build articles or threads that might have a combo that would help with some of the questions.

I did find this. A little hard to read 2 pgs. of that small print. Westech's dyno has always seemed to me a little friendly with the numbers, but it's still a impressive build. http://www.moparmusclemagazine.com/techarticles/mopp_0209_383_engine_restore/index.html
Click to expand...

I've run on Westech's dyno and if anything it seemed a might stingy. Steve D. & Steve B. are pretty sharp, that was a nice 383. We ran our 8:1 compression 383 on their dyno and with 906 heads and a small roller it went 494 hp.
 
IQ52 said:
I've run on Westech's dyno and if anything it seemed a might stingy. Steve D. & Steve B. are pretty sharp, that was a nice 383. We ran our 8:1 compression 383 on their dyno and with 906 heads and a small roller it went 494 hp.
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Thanks IQ52. I didn't have any first hand knowledge. I based that on alot of there "Brand C" tests that looked pretty optimistic to me:smile:.
That was one he!! of a 383 you had there....WOW.
 
Ok, so I got a chance to check the timing on my 383 yesterday. I found the intial to be at 4 degrees advanced and all in by around 18-20!! So I advanced it to total of 38 which leaves my intial at about 22 (it kind of bounces around a little so hard to see exactly where it is). Car runs much stronger! But....the only problem is it will barely crank over and after I shut it down and try to start it again it will not crank over. So, I had to back off of the timing for it to start easier, but then it runs sluggish again. Any advice? I was thinking either a more powerful starter, or I saw that MSD makes a starter saver that retards the timing when you start the car, and then returns to normal advance once the motor is over 800 RPM.
 
bb489ss said:
Ok, so I got a chance to check the timing on my 383 yesterday. I found the intial to be at 4 degrees advanced and all in by around 18-20!! So I advanced it to total of 38 which leaves my intial at about 22 (it kind of bounces around a little so hard to see exactly where it is). Car runs much stronger! But....the only problem is it will barely crank over and after I shut it down and try to start it again it will not crank over. So, I had to back off of the timing for it to start easier, but then it runs sluggish again. Any advice? I was thinking either a more powerful starter, or I saw that MSD makes a starter saver that retards the timing when you start the car, and then returns to normal advance once the motor is over 800 RPM.
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I don't think you should ever have to use a spark retard on a street car unless it's a extremely radical build. It's possible the numbers you are getting might not be 100% accurate due to a slip in the timing ring. Only way to verify it would be to bring the engine to true TDC and check the mark. Also, other members have had issues when using dial back timing lights on MSD systems and recommened using old school standard lights. That aside, you advanced it far enough for a no start condition and then backed off some so your probably getting close to what it likes as far as initial timing. I'm not sure about this case, but member "67Dart273" speaks alot on rotor phasing and there is probably a chance if it's off that would be causing the hard start when you were advanced in the 20 range. Maybe one of the members will give there thoughts on that.

[ame="http://www.youtube.com/watch?v=aWMlNwGW0tM"]MSD Tech: Rotor Phasing - YouTube[/ame]
 
Just realized you may not get many responses here with this title. You may want to start a new thread in the "Big Block A body Tech" section regarding the timing/tune issues with a list of your combo to get others up to speed so you can get some more views?
 
I'm curious, at what rpm were you getting full advance?

It sounds like you have the large black busings in the MDS distributor which limits the mechanical advance to 18 degrees. I would put in the silver bushings and set the total at 36 degrees. That should get you to about 11 degrees initial timing. It is unlikely that cam will need more than 12 degrees initial to operate properly. If you don't have the springs and bushings to set the advance, order the MSD part number 8464.
 
Hey if you ever find out whats making the whistling sound let me know my Dart does the same thing. When I hammer it about the 4000-5000 rpm mark it has a quick whistle right before it shifts gears. I only have one belt and have looked at that before. I have tried it with a mech fan and electric fan and it still does the same thing. I just joke with people and say its the blow off valve for my imaginary turbo.
 
Sorry but if I missed it - what is the engine built with in terms of distributor, pistons, heads, and cam? Because for the running issues, you don;t give anywhere close to enough info.
On the rear - the fact that it has fresh clutches and was "done right" really doesnt mean it's any tougher than a stock D60 sure grip with some years under it's belt. If the diff springs are original they are not as stif as they could be and that's what really makes it limited slip or behave more like an open diff. As for the 1st and 2nd gear bit... The torque load in 1st is much greater, so it "shocks" the diff more and once both tires are spinning, it doesnt take much to keep them both spinning. 2nd gear does not shock really at all because of the convertor and less torque multiplication of 2nd gear itself. I'd say the Grip is weak and you will want to avoid the one wheel peeling. Because in a short time it will start doing it in first too.
On the whine - as they said - check the fan if it's belt-run. Also tighten the belts. 3/4 of slop IMO is too much. I like less than 1/2" of movement and preferably closer to 1/4".
 
moper, some information in Mopar Performance Isssues -- "383 question".
 
Moper: engine specs in previous post, but here they are again:

1971 383 Magnum
Stock pistons as far as I know
452 Heads "fully" ported as told by previous owner. Milled 0.060
Compression: I was told by prev. owner 9:1
Comp XE 268 hydraulic cam
Distributor is a Mopar Performance one. NOT an MSD distributor. It is, however, hooked to an MSD 6 box.
Demon 650 Vac Sec carb.
Holley Street Dom. manifold
Long tube headers.
 
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