For better drivability, replace M1 with Weiand from craigslist?

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JoesEdge

JoesEdge

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Ok, so I recently got this Duster running a warmed up 360 and I've been trying to get it road worthy.

Throttle response sucks and I believe it's due to the intake, carb, or combination of both. Also, I can't seem to get it to idle much less than 1,000 RPMs. I'm guessing that could be due to the cam (don't know the specs), or the intake/carb.

I haven't looked up the numbers yet to determine the model of Holley carb. If you notice, it doesn't have a choke. I need to see if one can be added. The manifold appears to be the M1 single plane.

I found the following intake manifold on Craigslist and wanted to get you guys opinion on it. I was never a huge fan of Weiand manifolds, but was hoping it could do the trick to get better drivability and hopefully better idle.

http://losangeles.craigslist.org/lgb/boa/4300115719.html

So what do you think? Would being spreadbore be an issue?
 

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I bet it is the issue. The plenum design of an m1 is for a square bore carb. When I put a 750 dp with 4 corner idle adjustment I picked up 2 tenths in the 1/8. Edit, you do have 4 corner idle. Have you tuned the carb
 
The Weiand is a great street intake, but the big question to answer here, is the duration, lift and lobe separation of your cam.

For all we know, it could be matched to the power output range of that M1 intake and the jetting and CFM of that carb.

You could put some combination of more mild street manners on top of the engine and still have a cam that will never idle well under 1000rpm, by its own design, if it has enough overlap and lack of valve separation angle.

If you can figure that cam out, you'll be better off for it and parts selection.

If you are after better street manners, without pulling and checking the cam, you could just buy another cam that was set up for the Weiand, jets for the Holley and a choke to start with.

I'd do it all, or at least figure out what that cam was, before buying parts, unless I was determined to do something easier on the street, then I'd skip checking and buy everything.
 
daredevil said:
I bet it is the issue. The plenum design of an m1 is for a square bore carb. When I put a 750 dp with 4 corner idle adjustment I picked up 2 tenths in the 1/8. Edit, you do have 4 corner idle. Have you tuned the carb
Click to expand...

Nope. I haven't touched the carb at all. I did mess with the screws on the side and the idle did get much better. Drove a bit better too.

It's a 3 speed manual and it doesn't like me lightly touching the gas pedal to go from a dead stop. I have to give it more gas.

The Holley seems to be (from the numbers) a 4779-9 (model 4150). I cross checked that to a Holley 750 double pumper. Seems kinda big for street use. Any opinions?
 
DaveBonds said:
The Weiand is a great street intake, but the big question to answer here, is the duration, lift and lobe separation of your cam.

For all we know, it could be matched to the power output range of that M1 intake and the jetting and CFM of that carb.

You could put some combination of more mild street manners on top of the engine and still have a cam that will never idle well under 1000rpm, by its own design, if it has enough overlap and lack of valve separation angle.

If you can figure that cam out, you'll be better off for it and parts selection.

If you are after better street manners, without pulling and checking the cam, you could just buy another cam that was set up for the Weiand, jets for the Holley and a choke to start with.

I'd do it all, or at least figure out what that cam was, before buying parts, unless I was determined to do something easier on the street, then I'd skip checking and buy everything.
Click to expand...


Any way to check the cam specs without pulling out of the block? If I do have to pull it out of the block, I might as well pull the engine out and have it looked over completely.

I do admit, it sure does sound healthy past 3,000 RPMs!
 
I think you need more initial timing. If its not 15+, that will probably fix your problem. You'll have to remove total timing as well.

A lot of "carb" problems are really just improperly set ignition timing.
 
goldduster318 said:
I think you need more initial timing. If its not 15+, that will probably fix your problem. You'll have to remove total timing as well.

A lot of "carb" problems are really just improperly set ignition timing.
Click to expand...

I've wondered about the timing. I haven't set timing on a car in a very very long time. As of late, all my cars have been computer controlled. I guess now I need a timing light.

But what do you mean by "remove total timig"? Are you talking about when distributor advances?
 
The way that engine is set up now, looking at the lack of choke and big single plane, makes me wonder how the idle quality is and what that cam is.

There are ways of using a mic and a solid lifter to check lobe lift x1.5 to get actual lift. You can also check duration from .050" lift on the crank, with a degree wheel on the harmonic balancer, or timing tape. It's best done with a piston stop to correct and find actual zero and mark it on the balancer, instead of trusting the mark as not being shifted from the rubber in the balancer.

Typically, lift x 1.5 will give you an idea of it's range, as cams get bigger in lift, they usually follow with duration and overlap, giving you some idea of RPM range that it's intended for.

I'd start by popping a valve cover, pulling a rocker shaft and at least checking the cam lift, with the pushrod and hydraulic lifter unloaded, with a mic and magnetic base.

You can put a piece of wood with a channel in it or something like angle steel under the pushrod to help guide the pushrod, like a pool cue, to help keep the correct pushrod angle. It won't work with the rockers in place, because the spring pressure from the valves will compress the hydraulic lifters.

Just be sure that the mic is at the same angle as the pushrod and you can get pretty darn close to actual lobe lift measured. It would only require pulling a valve cover.

If you check intake and exhaust lobe lift and multiply it x1.5 and it's up in the mid to low .500s, you can assume that you've got a cam that was made to run in the higher RPM range.

If it doesn't hit 500 after multiplying the measurement x1.5, you've got the wrong intake for your application.
 
Let's start with a actual manifold vacuum reading..... Let's start with a vacuum guage reading... Around the corner ,from the fuel mixture screw. Thewe is a 3/16' vacuum nipple tube.Hopefully,it's covered. If not,that's one of the problems. Hook up the vacuum gauge,,get a reading . Let,s start there....
 
Try a bigger pump shot and adjust the 4 plate level idle screws for best idle. Thats a great carb for tuning. Keeps any corner from being lean.
 
goldduster318 said:
I think you need more initial timing. If its not 15+, that will probably fix your problem. A lot of "carb" problems are really just improperly set ignition timing.
Click to expand...


Yes. ^^^^^^^.

And as "bomber" said, a good manifold vacuum reading would help the diagnosis also.
 
A 750 carb isn't too big for street use on a healthy 360. Heck I know a guy running dual 750's on a tunnel ram on the street and it runs fine. It's all in the tuning. I bet Goldduster hit the nail on the head. So many times guys stick a big cam in an engine and just expect it to run without doing any other mods that are ABSOLUTELY necessary. The timing curve is one of the biggest overlooked mods that should be done when you put a big cam in an engine. Big cams generally drop low speed efficiency so thus the reason to need more initial timing. Of course you can just jack the distributor around and get more initial timing but then you run into the problem with it having too much total timing so you have to limit that somehow. How you limit it depends on what distributor design you have. If it's a factory distributor here's an article on limiting total timing.

http://www.moparmusclemagazine.com/...mopar_electronic_ignition_system/viewall.html

Once you verify the timing curve is correct it's onto carb tuning. You always tune the ignition first because it affects carb tuning.

BTW: a simple and cheap way to make your hot rod less cold natured is to install a block heater and plug it in 3-4 hrs. (or the night before) before you plan on driving it. I put one on mine ($25 at NAPA) and whenever I decide to drive it I plug it in in advance and let it warm up. Fires right up and takes right off. No more sitting there for 5-10 minutes feathering the gas to get it warmed up enough to drive. Saves fuel too.
 
I have M1 single plane w Holley 750 DP on my .555/.566 solid roller 340. Idles @ 800 no problem. Im thinking its in your tuning.
 
Here are the issues that I see:

1. I knew an engineer that worked in the Chrysler race group a while back. He told me that when they dyno tested the M1 intake, they found it had a lean condition on #8 cylinder in the upper RPM band.

I would ditch the M! for a LD340, edelbrock performer rpm, wiand stealth dual plane intakes.

2. I would install a set of Rhoades variable duration lifters and Rhoades only. They work the best. They bleed down at idle and take away approximately .025" lift and 15° duration, then they "pump up" and give full lift and duration of the cam by 3500 rpm. This increases idle vacuum, low end torque, mid range power, without sacrificing any top end. They also allow a more radical engine to idle at a lower rpm than with standard lifters. You get to have your cake and eat it too with these....

3. If you like your carb, and can get a choke installed try using that. I would myself, downsize to a 600 vacuum secondary list # 80457. This carb is calibrated for a late 60's vintage car and comes with electric choke for around $300 new from Mancini.



Something doesn't seem right with the Wiand stealth 8022 on ebay.


Here is the info from the Holley web page (they own Wiand):

CHRYSLER SMALL BLOCK STEALTH™ INTAKE MANIFOLD PART #: 8022

Features
High Rise Dual Plane Design
Square Bore Carburetor Mounting Flange
No EGR Provisions
Power band: Idle-6800 RPM
Height: Front 4.88", Rear 5.94"
Port Size: 1.96” height 1.00" width

View attachment medium8022.jpg

https://www.holley.com/8022.asp

Look at the picture of the 8022 intake from the Holley web page and then look at the picture from the ebay listing below:

View attachment ebaystealth.jpg

The stealth 8022 is supposed to be a square flange carb mount, but the one on ebay has been machined out for a spread bore. It is advertised for 318-340-360, and I believe has the larger 340/360 port size (not 100% sure).

The Wiand stealth is a great street manifold with a power band from idle to 600 rpm. I've ran one before and was happy with it. I would pass on the ebay intake and either find another used one that has the square bore flange or order a new one.


 
Krazy. people keep dissing these...they are fools, my man... Correct preload, these are such a tuning tool...
 
These are great tips, let me see if I can address them all.

DaveBonds:

Sounds like a pretty straightforward method. Looks like all I need is a degree wheel and a micrometer. I have plenty of angle iron in the garage since I've been trying to teach myself to weld. But, did you actually mean a "dial gauge", instead of "mic", like this one:

MagDialGauge.jpg


Seems like that would be perfect for the job since it has a magnetic base.

Abodybomber:

You know, considering that it takes plenty of effort at the brake pedal to stop, I had wondered if my vacuum was too low. Maybe that's an indication of not enough vacuum, or a bad booster. I guess I need a vacuum gauge.


Fishy68:

Thanks for the tips. I believe I have a MSD distributor, I'll double check tomorrow. I know for sure I have a MSD blaster coil and MSD 6A (model 6200) ignition box. Sounds like I need to research on how to tune those.

As far as the block heater goes, isn't that for really really cold climates? I'm in Los Angeles. We haven't even had a winter yet. LOL

swinger340:

Wow..800 RPM is nice idle. How is your throttle response? Yeah, from what I am gathering my problem could be tuning. But, I still should probably figure out the cam so I can tune everything else accordingly.

krazykuda:

I agree. That intake on Craigslist or Ebay didn't seem right to me as well. The date stamping says it was made in 2006. Maybe it was an old design? I was trying to save a buck, but maybe I should stick to a squarebore design.

Ideally, I'd like to find a good used Performer RPM or Performer RPM Air-Gap. I've read the Air-Gap intakes are really good.

I did think about getting a smaller carb, but maybe I should just try to tune what I have first and see how it runs.

Nice tip on the Rhoades lifters. That's pretty interesting how they work. I'll have to look into those some more. Honestly, I don't even know if I have solid or hydraulic lifters. The valves are kinda noisy though. I think the last time I drove a vehicle with solid lifters was a '69 Beetle and I quickly got tired of adjusting the valves.


Damn, so it seems like I will be spending more money in tools that I will in shiny new car parts! LOL
 
Oh this is a little off topic, but since we're talking about tuning. The previous owners installed a oil pressure gauge. It marks like 90 psi. Isn't that kinda high?
 
Yeah. I was talking about limiting the maximum timing when the distributor advances. I would get a dial-back timing light and a vacuum gauge.

Keep advancing the distributor until you get maximum vacuum (and idle speed), if this seems like a reasonable value (not like 40...something like 15-25), kill the engine and then try to re-start it after a second or two. If it starts, this is your ideal initial timing. Idle the carb back down with the curb idle screw if you have to, then adjust the mixture screws (making sure they are even) until you get the highest vacuum again.

Figure out the total timing by revving the engine and seeing where it stops advancing (probably running it at 3000 rpm will do it). You'll want the total to be between 32 and 36 to start. You can either weld the slots in the distributor, or you can buy one of those limiting plates from FBO.

If you do decide to weld the slots, measure the length of the slot with a caliper, subtract the diameter of the pin, and then do the following ratio. New slot length=(old slot length*new degrees advance)/old degrees advance where the degrees advance is how many degrees it will advance from idle to full advance.
 
goldduster318 said:
Yeah. I was talking about limiting the maximum timing when the distributor advances. I would get a dial-back timing light and a vacuum gauge.

Keep advancing the distributor until you get maximum vacuum (and idle speed), if this seems like a reasonable value (not like 40...something like 15-25), kill the engine and then try to re-start it after a second or two. If it starts, this is your ideal initial timing. Idle the carb back down with the curb idle screw if you have to, then adjust the mixture screws (making sure they are even) until you get the highest vacuum again.

Figure out the total timing by revving the engine and seeing where it stops advancing (probably running it at 3000 rpm will do it). You'll want the total to be between 32 and 36 to start. You can either weld the slots in the distributor, or you can buy one of those limiting plates from FBO.

If you do decide to weld the slots, measure the length of the slot with a caliper, subtract the diameter of the pin, and then do the following ratio. New slot length=(old slot length*new degrees advance)/old degrees advance where the degrees advance is how many degrees it will advance from idle to full advance.
Click to expand...

Thanks for the tips! Seems pretty straightforward.

david340 said:
If you get rid of the M1 I would be interested in buying it
Click to expand...

It will probably be awhile before I get to the stage of selling it. I need to replace it first. But send me a PM and you'll have first 'dibs'. But, if you have a comparable dual plane (like a Performer RPM) intake I'd be willing to trade too.
 
I like the Ede LD340/Performer RPM/Air Gap because they have the stock coil bracket mounting bosses. The weiand/LD4b do not. Those 3 intakes will mudhole that m1 which I think is a horrible intake except in very narrow window of performance applications. The C/L intake has been modified like many ld340's were over the years.

Get a vacuum reading as suggested, that will tell you a bit about what's going on. Adjust idle mix screws to highest vacuum level. A big MP cam like the 292 hyd will have under 9" of vacuum at idle which can be difficult to deal with on a street car.

Don't worry about the port size on the intake, it's really insignificant in the big picture here.

When you add timing at idle, if it increases rpm, reset to your base idle speed and check vacuum. If it's up you are good, try it again. If you add timing without resetting speed of course the engine will pick up rpm and vacuum will go up. There will be a point that it will stop and that's usually very far out of bounds.

It's a bit of a process, once you get it, the results are usually very good.
 
JoesEdge said:
Oh this is a little off topic, but since we're talking about tuning. The previous owners installed a oil pressure gauge. It marks like 90 psi. Isn't that kinda high?
Click to expand...


No, it's not. I had a 340 with a high volume oil pump and high pressure spring that would put out 100 on cold start.
 
JoesEdge said:
Fishy68:

Thanks for the tips. I believe I have a MSD distributor, I'll double check tomorrow. I know for sure I have a MSD blaster coil and MSD 6A (model 6200) ignition box. Sounds like I need to research on how to tune those.

As far as the block heater goes, isn't that for really really cold climates? I'm in Los Angeles. We haven't even had a winter yet. LOL
Click to expand...

OK. If it is a MSD it's much easier tuned than a stock dist. All you do is replace a little bushing in it. I could explain how to do it but its' just as easy to get the part # off of it and look on MSD's website for the directions. It has pictures also that'd make it easier to understand than my explanation. After you experiment with the timing like Goldduster said which is the proper way to find out what timing your engine likes, you then install a timing advance limiter bushing that's the correct size for what your engine wants. MSD's smallest bushing is 16 degrees if I remember right and many times you'll find you need a smaller one to get the timing right on the mark. If so contact Crackedback-Rob and he can fix you up as he has a source for them. Gotcha on being near LA. I didn't install the block heater on mine just because we get cold here, it's beneficial even when it's 80 degrees out. When it's 80 degrees and the engine hasn't been ran that means the engine is still approximately 100 degrees colder than it operates at. Fuel doesn't vaporize good at those lower temperatures and vaporization is what it's all about. Since I installed mine the plugs run cleaner too cause when it's cold (even 80 degrees) you generally have to feather the gas pedal the first few minutes until it want's to idle on it's own. That feathering creates a rich condition that can attribute to fouling plugs sooner than normal. My fuel mileage went up 1-2 mpg on average since installing it also. I believe that is to due with not having to sit there for 3-5 minutes feathering the gas pedal to get it warmed up which you'll have to do with just about any high performance engine with a big cam
 
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