Is there an optimal setting for the timing?

[johnnycharger]

Hi Guys
I need to get my timing set correctly and I am no master mechanic...
Here is what I have
383 stock cam heads and innards
Holley 750 double pumper
Edelbrock performer intake
Blaster 2 coil
Pertronix box
Fire core wires
Ngk plugs
Vacuum advance disconnected

I think that is all of the details.
What should my timing be set at?

[Ghoste]

You can probably start at 16 initial and 32 total but once you get into it the car may tell you different.

[myk]

The optimal setting is whatever your engine likes; no two engines are the same.  Set your initial timing to highest possible manifold vacuum, then test drive.  My engine went all the way up to 24* initial and highest vacuum, but I settled on 20* initial in the end...

[BSB67]

Try this

Total timing at 38° w/o vacuum advance
Check and record timing at idle  v/o vacuum advance
Reconnect the vacuum advance to ported  vacuum and go for a test drive, and report back how it drives.

[John_Kunkel]

  That's more like it. Fuel quality will dictate final setting.

[68charger440]

That's more like it. Fuel quality will dictate final setting.

"Fuel quality"... Now that's an oxymoron if I ever heard one.

[John_Kunkel]

You can get quality fuel if you want to mortgage your house to pay for it.

[68charger440]

You can get quality fuel if you want to mortgage your house to pay for it.

Courtesy of your EPA public service regulations!

[johnnycharger]

Try this

Total timing at 38° w/o vacuum advance
Check and record timing at idle  v/o vacuum advance
Reconnect the vacuum advance to ported  vacuum and go for a test drive, and report back how it drives.

Ok. So apparently I know less about timing than I thought.  Don't kill me because of my ignorance. So my vacuum advance is disconnected and  I turned my distributor until my timing was about 30 hard to be exact because my marker stops at 10.  Did I do it right? I don't quite understand the different timing terminology.  If I rev it up it goes much farther. I did notice quite a bit of difference from where it was set to.

[johnnycharger]

[johnnycharger]

The second picture is at idle. The first picture is revved up at about 3000 rims or so..... I don't have a tachometer.

[68charger440]

30 seems like way too much initial to me.  I run mine at 18 initial and 34 total all in. , but these other guys know much more than me.

[Ghoste]

30 initial is too much.

[johnnycharger]

So... initial is at idle and total is when revved? Is this correct?

[68charger440]

So... initial is at idle and total is when revved? Is this correct?

Yes, and the total can come in at different rates depending on how your distributor curve is setup.

[johnnycharger]

Gotcha. Thank you. I will dial it back tonight and take it back out and see how it does.

[maxwellwedge]

You need to either buy a timing tape (cheapest) for the harmonic balancer or a roll-back, dial-back.....whatever you want to call them timing light to set total advance. I say invest in the timing light.....you can use it on other cars and it is a good tool to have.

[myk]

Buy a timing gun with an advance/retard feature.  I use THIS: http://www.nationaltoolwarehouse.com/INNOVA-Digital-Timing-Light-P18259.aspx?gclid=Cj0KEQjwnrexBRDNmZzNkf7c4c4BEiQALnlxhWuuLUD2j9JeOFOlQwm93xf3XBVT116TkIWmiWfCRPoaAn5T8P8HAQ

The Innova 3568 features a dial-back/advance feature AND a tachometer, all in one.  It's about a hundred bucks or so, but well worth it so that you can actually know what you're doing. 

Also, 30* initial may seem like a lot, but some guys, like good 'ol Ron, run 34* initial.  Now of course, his fire-breathing motor is a little different from ours, but the point is you have to experiment with your engine and see what it likes.  There is no "ideal" timing, as every engine behaves differently...

[Dino]

That's a good light, I bought one for around $70 I think.  Now that the engine is out it's a great time to stick some timing tape on the balancer though.   

I'm running 24 initial btw.

[firefighter3931]

With the stock cam it won't want a huge amount of base timing. I've found 15-16* to be the sweet spot with stock/mild builds and 36-38* total timing all in by 2500 rpm.

The stock distributor does not have a mechanical advance adjustment so that limits how much initial timing you can dial in. 

Example ; the stock dist has 30* of mechanical advance but your engine wants 15* at idle. Giving it the 15* it wants would result in a total timing of 45* which is too much (15 base + 30 mechanical = 45 total)

For now, just rev it up to 3500 and set the timing to 38* and re-check at idle. The difference between 3500 and idle is the amount of mechanical advance that is set up in that distributor. 

Report back with your findings 


Ron

[BSB67]

38 degrees is 2.38" on the balancer.  No need to buy a dial back light.  One more thing to be wrong and you will be chasing your tale forever trying to figure it out.  I have seen this happen twice, dial backs that were wrong.  And I've only used three.

Just put the make on the balancer, have someone rev it to 3500 rpm, line the 2.38" balancer mark to the "0" degree mark on the tab.

[johnnycharger]

I really appreciate the info guys. Your ways of explaining this has really helped me understand it. I made a make shift tab by tracing the lines on a piece of paper and then transferring it to another piece long enough to get to 38. I don't think it was too accurate. On the test drive it was slightly more sluggish than where I had it at before. I will make the mark at 2.38" below the line that is there now.

Question about 3500 RPMs... how accurate does that need to be? I do not have a tach but I have noticed that at about what I think to be in that range the  timing no longer advances. When it is at what I believe to be 3500 it steadies out. Is that correct?

[johnnycharger]

Sorry... I forgot to mention that after I set it to 38 (or in that area) when back at idle it was at 15*

[68charger440]

38 degrees is 2.38" on the balancer.  No need to buy a dial back light.  One more thing to be wrong and you will be chasing your tale forever trying to figure it out.  I have seen this happen twice, dial backs that were wrong.  And I've only used three.

Just put the make on the balancer, have someone rev it to 3500 rpm, line the 2.38" balancer mark to the "0" degree mark on the tab.

Just curious, why is it 2.38 and not 2.407?  Not that it would make a big difference.

[johnnycharger]

Whoops! I guess the line goes above the existing line when looking from the passenger side.

[myk]

Without a 'tach or a light I would adjust to best manifold vacuum, and then see what the test drives are like.

[BSB67]

38 degrees is 2.38" on the balancer.  No need to buy a dial back light.  One more thing to be wrong and you will be chasing your tale forever trying to figure it out.  I have seen this happen twice, dial backs that were wrong.  And I've only used three.

Just put the make on the balancer, have someone rev it to 3500 rpm, line the 2.38" balancer mark to the "0" degree mark on the tab.

Just curious, why is it 2.38 and not 2.407?  Not that it would make a big difference.

It's the units my yard stick is in.

[68charger440]

38 degrees is 2.38" on the balancer.  No need to buy a dial back light.  One more thing to be wrong and you will be chasing your tale forever trying to figure it out.  I have seen this happen twice, dial backs that were wrong.  And I've only used three.

Just put the make on the balancer, have someone rev it to 3500 rpm, line the 2.38" balancer mark to the "0" degree mark on the tab.

Just curious, why is it 2.38 and not 2.407?  Not that it would make a big difference.

It's the units my yard stick is in.

Can you give me a little more than that.
I thought it would be...
7.25×3.14159
=22.7765275

22.7765275÷360
=0.0632681319

0.0632681319×38
=2.4041890139

[johnnycharger]

So tonight I got it set to 38* total which left it at about 15* initial. It is running quite good. May need a minor degree or two adjustment to either side but is way better than before. Once I get the final dialed in I will let you know where it is at. Probably won't be until the weekend. Next will be on to adjusting my carb floats!
Thank you guys very much for all of your help!  

[firefighter3931]

So tonight I got it set to 38* total which left it at about 15* initial. It is running quite good. May need a minor degree or two adjustment to either side but is way better than before. Once I get the final dialed in I will let you know where it is at. Probably won't be until the weekend. Next will be on to adjusting my carb floats!
Thank you guys very much for all of your help!  

Good work,

The 15/38 should be perfect for that mild street build 


Ron

[BSB67]

So tonight I got it set to 38* total which left it at about 15* initial. It is running quite good. May need a minor degree or two adjustment to either side but is way better than before. Once I get the final dialed in I will let you know where it is at. Probably won't be until the weekend. Next will be on to adjusting my carb floats!
Thank you guys very much for all of your help!  

Good.  Sometimes it does not have to be complicated.

[johnnycharger]

Had some good fun burning gas around town today. The car did great. It is running much smoother and definitely starts much faster than before when the engine is hot.

[johnnycharger]

Finally hooked up the vacuum advance again. It is working great. This is the fastest it's been running for over a decade. 

Now I am looking at changing out my Edelbrock performer intake for an edelbrock DP4B. I see they get great reviews and maybe my hood mat won't rub on my aircleaner. Should this give me a noticeable power increase?

[XH29N0G]

My guess is that the changes will not have a very clear difference, but they are fun to make.  I played around with my 383 for a while with intake, headers, carb, heads, cam, etc....  It was a lot of fun and I learned a lot by making mistakes along the way.  It also made incremental differences, some I noticed and others I did not.  The biggest effect was when I changed the gears in my rear end.  (Also the most expensive single change). 

See what others say.  The key is probably to see what you are using the car for and how you enjoy it most. 

[BSB67]

Finally hooked up the vacuum advance again. It is working great. This is the fastest it's been running for over a decade. 

Now I am looking at changing out my Edelbrock performer intake for an edelbrock DP4B. I see they get great reviews and maybe my hood mat won't rub on my aircleaner. Should this give me a noticeable power increase?

If you are looking for the experience, go for it.  If you are looking for a performance improvement, don't do it.  Here is a little secret, they are basically the same manifold.  Shhhh.  I don't tell anyone I told you.

[johnnycharger]

Finally hooked up the vacuum advance again. It is working great. This is the fastest it's been running for over a decade. 

Now I am looking at changing out my Edelbrock performer intake for an edelbrock DP4B. I see they get great reviews and maybe my hood mat won't rub on my aircleaner. Should this give me a noticeable power increase?

If you are looking for the experience, go for it.  If you are looking for a performance improvement, don't do it.  Here is a little secret, they are basically the same manifold.  Shhhh.  I don't tell anyone I told you.

Really? That is disappointing.  I have been reading about them on the forum quite a bit and I thought it would perform better. I am never looking for more work just for the fun of it . I might need to remove my intake manifold for another issue and I figured it would be the best time to upgrade and it looks like the DP4B would be the best to get for my 383...

[c00nhunterjoe]

The performer rpm is about the best street intake for the car in my opinion. Dual plane that can act like a single plane. On a mild build i wouldnt run anything else.

[johnnycharger]

The performer rpm is about the best street intake for the car in my opinion. Dual plane that can act like a single plane. On a mild build i wouldnt run anything else.

Mine is a performer 383 not rpm. Is there much difference?

[Dino]

The performer rpm is about the best street intake for the car in my opinion. Dual plane that can act like a single plane. On a mild build i wouldnt run anything else.

Mine is a performer 383 not rpm. Is there much difference?

Day and night

[johnnycharger]

I have heard in the past that the performer 383 is a turd. Is that correct?

[Dino]

It's basically the aluminum version of the stock intake so some people would call it a turd.  I have the same on my 440 and I took it off.  I have the stock 71 intake which is supposedly the best flowing stock intake mopar made so it's going to be used in its place.  This is just because I wanted the stock manifold, performance wise I'll never know the difference.  If you're not going to drive the car hard then leave the performer in place, but if you want some more oomph then you should look into the bigger intakes such as the rpm.  Hood clearance will go out the window though, you'll need a drop base air cleaner.

[johnnycharger]

Ok. My performer 383 was installed when i bought the car back in 1998. I don't take the car to the track but I do stomp on it every time I take it out. I may need to remove my intake to do another repair (occasional knocking that I believe may be a lifter). I have the opportunity to grab a DP4B locally for $150 and I am trying to determine if it is a good upgrade to switch to or if I should just keep what I have.

[johnnycharger]

Oh.... and I already have a problem with the aircleaner rubbing on the hood mat.

[Dino]

The DP is a good intake which I would probably buy if I had a 383 and no intake.  But seeing you have the performer you may want to save your money.  Except for the look you'd never notice any difference on the street.

How much is it rubbing the hood mat?  Do you have a tall carb spacer installed?  Which air cleaner do you have?

[johnnycharger]

The carb spacer is not too tall.  I don't know what kind of air cleaner it is. The rubbing drives me nuts...

[johnnycharger]

You can see where the top has left a ring and the nut has made a mess.

[johnnycharger]

I don't think my air filter could be much thinner.

[Dino]

The nut is pretty big but that's crazy how the cleaner housing rubs like that.  Your carb and cleaner are not tall at the least.  I have heard people complain about the air cleaner hitting the mat so there may not be any other solution than removing the mat or replacing it with a molded mat which may or may not improve the situation.  I'm not familiar with Holleys but hopefully you can use a drop base fo that cleaner and solve the rubbing issue.

[johnnycharger]

Yea it is frustrating.  The base now a little drop to it but I don't think it can go much lower without interference. I read on one of the posts that the DP4B may be shorter...

[Dino]

I doubt it will be any significant amount.  The performer is pretty low to begin with but it doesn't hurt to compare them!

[XH29N0G]

Yea it is frustrating.  The base now a little drop to it but I don't think it can go much lower without interference. I read on one of the posts that the DP4B may be shorter...

There are various drop bases that can be used to fit a performer RPM or other air cleaners under the hood.  I am using a 1.75" drop 16" diameter made by keyser manufacturing (Summit carries them) with a 1/2 in spacer and an air filter at little under 3" height.  The cleaner has a recessed nut and just misses the insulation.  (I ran a 3.75" filter without spacer, but that pressed the top of the cleaner against the hood pad.)  I am running a quick fuel carb, which I think is the same height as your holley but does not have a choke horn. 

I still do not know if you will notice the change made by the intake, but tinkering can be therapeutic.   Is your car auto or manual?

[BSB67]

The Performer RPM is too much for your stock 383.  The standard Performer/DP4B will easily support 375 hp without being the weak link.  You're no where near that. 

I have both the Performer and DP4B, in every meaningful way, they are the same.

Dyno testing puts them within a few hp of one another, i.e. within dyno repeatability error.

If your air cleaner is into your hood on a 383, you need to get a different air cleaner with a drop base. 

[Ghoste]

And if you do go with the Performer RPM the drop base will become pretty much mandatory.

[firefighter3931]

The Performer RPM is too much for your stock 383.  The standard Performer/DP4B will easily support 375 hp without being the weak link.  You're no where near that. 

I have both the Performer and DP4B, in every meaningful way, they are the same.

Dyno testing puts them within a few hp of one another, i.e. within dyno repeatability error.

If your air cleaner is into your hood on a 383, you need to get a different air cleaner with a drop base. 

I have to agree with Russ on this ; the 383 Performer & DP4B are identical so there's no performance advantage switching from one to the other 

When talking about a 440 there is a big difference. The CH4B is a far superior manifold vs the 440 Performer. The runners on the later 440 Performer are substantially smaller and way more restrictive. Good manifold for a towing vehicle that won't ever see the high side of 4500 rpm. 

So....Edelbrock got it right with the lowdeck performer but dropped the ball on the raised deck 440 Performer which is a shame. 

To answer your question Johnny :  Stick with the manifold you have...it's more than up to the task for your current build 


Ron

[johnnycharger]

The Performer RPM is too much for your stock 383.  The standard Performer/DP4B will easily support 375 hp without being the weak link.  You're no where near that. 

I have both the Performer and DP4B, in every meaningful way, they are the same.

Dyno testing puts them within a few hp of one another, i.e. within dyno repeatability error.

If your air cleaner is into your hood on a 383, you need to get a different air cleaner with a drop base. 

I have to agree with Russ on this ; the 383 Performer & DP4B are identical so there's no performance advantage switching from one to the other 

When talking about a 440 there is a big difference. The CH4B is a far superior manifold vs the 440 Performer. The runners on the later 440 Performer are substantially smaller and way more restrictive. Good manifold for a towing vehicle that won't ever see the high side of 4500 rpm. 

So....Edelbrock got it right with the lowdeck performer but dropped the ball on the raised deck 440 Performer which is a shame. 

To answer your question Johnny :  Stick with the manifold you have...it's more than up to the task for your current build 


Ron

Thanks Ron!

[BSB67]

Thanks Ron!

Any everyone else too, right?

[johnnycharger]

Thanks Ron!

Any everyone else too, right?
Of course! Sorry(it was early)... thank you too and to everyone else that have been chiming in!