Time for More Horsepower

[Charles Furman]

Well, I have 3,000 miles on my 1949 Dodge B1B108 Woodie now and it is time to add a little more horsepower.

My Dodge is 100% stock except for disk brakes in the front and a 373 rear end. At 65 mph I tach about 2500 rpm. My biggest issue is that when I pull long hills I max out at 50 mph with my foot in it all the way.

I am not looking to burn rubber, but I would like to add some horsepower without sacrificing reliablity. The big difference between my woodie and a stock BIB108 pickup is the weight of the body. My Dodge drives like its carrying a full load of lumber all the time. This makes for a very smooth, solid ride, but it makes hills a little more challenging.

I am initially looking for bolt on solutions and I would be very interested in hearing from some of you who have ventured down this road. I know Reg Evans and Don Coatney have a vast amount of experience with aftermarket and custom perfromance stuff, but I am sure that there are many more of you that can also give me some guidance.

I would be interested in what worked and what didn't work. I would like to know where to get need parts and even what I might expect to pay.

If this type of discussion has been documented somewhere else, just point me to it.

Thanks,

Charles Furman

[TodFitch]

Maybe a 4.11:1 rear end would get your RPMs up to where the engine is putting out more power.

[Don Coatney]

Biggest bang for the buck is shaving the head. I have heard tell of others taking as much as one hundred thousands off but I would be a bit more conseverative for reliability. Fifty thousands should be very noticable and your engine will still look stock.

Is your vacuum advance working and where do you have your timing set?

[greg g]

I took .040 off my head and .010 off the block, and my 230 is very sprited.

So mill the head, add dual exhaust, and get a 20 dollar carb adapter and put on a 2bbl carb from a 318. In 56 Plymouth had a 2bbl option which added 8 hp. The 2bbl, higher compression, and freed up exhaust might give you about 10 or 12. A later and less restrictive air filter could also kick it up a bit

By the way, my machine shop charged me 40 bucks to mill the head so its a pretty big bang for the buck. I believe the conventional wisdom is you can go .090 and still run regular gas.

10 or 15 hp might get you up the hills at 60.

[Olddaddy]

I agree with Don and Greg, as usual. However, one reason your truck will only do 50 mph is the rear end ratio. Ideally, you could go to an overdrive, say a T-5 borg warner and get more mph for rpm. If you could do that and go to a 3:90 or 3:73 rear end you would do better also.

[greg g]

Charlie his first post did mention that he had a 3.73 ratio rear end. It seems a stock motor should pull more mph the 50 with that ratio. unless he has really short tires.

[Young Ed]

I believe his factory tires would have been 16s. 16s with a 3.73 should go well over 50. I think a temporary tach would be a good indicator of whats going on. My p15 with a 3.73 and 15s does 60-65 easily

[Charles Furman]

Thanks for the lively discussion guys.

Actually, I can run easily at 70-75 on flat ground with my 3:73 rear-end. At 65 mph, I am taching about 2500 rpm. The problem is when I try to pull a long grade. The added weight of the woodie body is like trying to drive a pickup up hill with a full load.

I like the idea of shaving the head .050, adding a dual exhaust split manifold, and adding more carburetion.

Would it be better to use a 2 barrel carburetor with an adaptor or try to find a manifold that will take two 1 barrel carbs? Also, if I go with a 2 barrel carburetor, what carb do you recommend?

With all these changes, are there adjustments I will need to make (timing, plugs, etc)? Which adjustments go with which changes?

Thanks

[greg g]

If you want to retain more of a stock appearance, the 2bbl is probably the way to go, plus you don't need to synch the carbs, fool with the linkage. I have found that 3 to 5 degrees of advance at idle with todays fuels. Set it with a vacuum gauge to the highest vacuum at idle, and then check with a light and see where it is.

Carter BBD or equivelent. Used on Jeep 258 cu in 6 so size and flow would be comparable. These had a reputation as being poor carbs due to low speed running problems. But the problem is easily fixed. They should be easily available from wrecking yards or as remaned units. pre 81 for no electronic managment. There are also Holleys and rochesters that are similar. AS mentioned if you can find one from a 273/318 MOPAR it should be compatable also.

You can also get a weber that has a progressive situation with an ondemand secondary for power when you need it and frugal cruising, The 32/36 DGEV model claims 18% hp increase over the stock factory carb as well as 10-20% fuel economy increase. The 38 DGEV model is designed for higher power applications where headers, cam, and aftermarket intake manifold are used. $$

But check James Douglas's posts regarding running a single webber on his Desoto motor.

Perhaps the one recommended for the bigger jeep engine adresses that situation.

[Reg Evans]

Charles,

These manifolds will give you a boost.

http://www.stoveboltengineco.com/acartpro/product.asp?productid=148

As mentioned already several times have the head milled .050 - .070 and make sure your vacuum advance is really operating.

I noticed my B series truck was not pulling a long grade in my area like it use to because the vac adv stopped holding a vacuum. I tested mine by sucking on the vac line and then holding the vacuum with my tongue. It wouldn't hold the vacuum.

Warning.....your taste buds may protest a little.

Oh yeah.....Maybe that passenger side rear view mirror is creating too much drag. I accept returns.

[MBF]

I run a Carter BBD on m 78 1/2 ton w a /6. There are several different versions of these carbs-one designed for a V8, the one with the smaller throat designed for the /6, and the new versions with all of the polution controls. If you're buying a used one, make sure it is the smaller throated version, and check the throttle shaft for wear. These carbs are notorious for needing to be rebushed due to vac leaks at the throttle shaft-even rebuilt ones sold by NAPA or Advanced Auto. I'll try to find a link to the online service manual for these-it makes all the difference when setting up the carb after rebuild. I may convert my 52 to one of these if I can find the adapter that someone mentioned. Mike

[Charles Furman]

Mike,

Let's keep in touch. Maybe we can come up with a solution we both can use.

Charles

[Don Coatney]

When I rebuilt my engine I installed a NOS vacuum advance that I found on the bay. My engine ran great. I thought it was still running great until I checked my vacuum advance and found it was not working. Reg Evans had one that passed his tongue test (thanks again Reg and I hope your taste buds return to there normal abnormal state soon) and sent it to me. I installed it and my engine ran better than when I first ran it after the rebuild.

A few weeks ago, as I was leaving the Friday night cruse in here in the Boro, I got in a race with a Hemi powered 56 Desoto while I was heading home on the interstate. The guy was right on my bumper and pulled a slingshot at about 80 and passed me. Like Clancy, I lowered the boom. When I passed him my tach was reading around 3500RPM's in overdrive gear. This calculates to around 95MPH. I dont think I could have done this without a working vacuum advance.

[Reg Evans]

Don,

My taste buds are OK now but I think something really horrible has happened to my taste in boating attire.

Hey.....Glad I could help with your most recent race.

[old woolie]

To test a vacuum advance or any other dashpot, I find it easier to push in the business end and then put a thumb or finger over the vac. port. If it stays in it's good, if it comes out it's bad. Try it. As far as vac. advance helping you under hard acceleration, think about it. What do your vac. wipers do?

[Don Coatney]

To test a vacuum advance or any other dashpot, I find it easier to push in the business end and then put a thumb or finger over the vac. port. If it stays in it's good, if it comes out it's bad. Try it. As far as vac. advance helping you under hard acceleration, think about it. What do your vac. wipers do?

Old Woolie;

The vacuum advance vacuum supply is connect to the port on the carburetor slightly above the throttle butterfly. At idle there is no vacuum at this port. Once the throttle butterfly is opened there is vacuum and the ignition timing advances. This helps under hard acceleration.

The wiper vacuum supply is connect to the intake manifold. At idle there is close to full engine vacuum available to operate the wipers. Once the throttle butterfly opens manifold vacuum drops to close to zero.

When the throttle butterfly closes such as when coasting down hill or to a stop there is no vacuum to the advance and the timing retards as it is not needed. The manifold vacuum increases to maximum when coasting down hill or to a stop and the wipers run at full speed.

Think about it. The two vacuum supplies operate opposite of each other.

[Don Coatney]

Don,

My taste buds are OK now but I think something really horrible has happened to my taste in boating attire.

Hey.....Glad I could help with your most recent race.

Reg;

Boat people always dress funny if they dress at all:cool: Curious what the guy behind you is looking at. Hope it is not your behind:D

[Charles Furman]

OK, you guys made me get my hands (and mouth) dirty.

I did Reg's "suck test" on the vacuum advance unit all the way from the vacuum line at the carb and the vacuum advance unit advanced and held. I then put the distributor back together and ran the engine up to 1300 rpm and the timing advance 10 degrees and held just like the manual said it should.

I checked the timing at idle and it was set at about 1 degree ATDC. The manual says it should be set at TDC. I reset it to either TDC or, maybe, 1 degree BTDC (it's hard to tell with my eye sight).

The only thing I haven't tried yet is setting the timing at idle using a vacuum guage. Can someone please explain this concept further. Do you set it to carb vacuum or intake manifold vacuum? I thought carb vacuum was supposed to be zero at idle. I guess I am just slow, but I don't understand this concept.

[Reg Evans]

She's not a guy Don.

She's our Gold Country Fair Queen voted in by us hill folk.

We finally got us a purdy one this year compared to last years queen shown here.

[old woolie]

Old Woolie;

The vacuum advance vacuum supply is connect to the port on the carburetor slightly above the throttle butterfly. At idle there is no vacuum at this port. Once the throttle butterfly is opened there is vacuum and the ignition timing advances. This helps under hard acceleration.

The wiper vacuum supply is connect to the intake manifold. At idle there is close to full engine vacuum available to operate the wipers. Once the throttle butterfly opens manifold vacuum drops to close to zero.

When the throttle butterfly closes such as when coasting down hill or to a stop there is no vacuum to the advance and the timing retards as it is not needed. The manifold vacuum increases to maximum when coasting down hill or to a stop and the wipers run at full speed.

Think about it. The two vacuum supplies operate opposite of each other.

I agree for the most part, but at wide open throttle I don't think there would be much vacuum at the vac. advance, could be wrong,wouldn't be the first time. If manifold vac. drops to near zero when throttle plate opens, how do the wipers work when cruising at 50 - 60 mph?

[Don Coatney]

I agree for the most part, but at wide open throttle I don't think there would be much vacuum at the vac. advance, could be wrong,wouldn't be the first time. If manifold vac. drops to near zero when throttle plate opens, how do the wipers work when cruising at 50 - 60 mph?

Vacuum advance at wide open throttle is as good as it gets. The carburetor butterfly port acts as a venturi. As long as there is air flowing through the throat of the carburetor there will be vacuum generated at the ported vacuum advance connection. Works the same as the crank case venturi draft tube. Google PIAB vacuum generators that work using compresed air. Same principle.

Wipers dont work well at wide open throttle. But at partial throttle while cruisng at any given speed there is ample manifold vacuum to make the wipers swipe.

[Don Coatney]

She's not a guy Don.

She's our Gold Country Fair Queen voted in by us hill folk.

We finally got us a purdy one this year compared to last years queen shown here.

Reg;

The guy you said was a girl sure has a big hunk of wiskers below her nose.

[old woolie]

Vacuum advance at wide open throttle is as good as it gets. The carburetor butterfly port acts as a venturi. As long as there is air flowing through the throat of the carburetor there will be vacuum generated at the ported vacuum advance connection. Works the same as the crank case venturi draft tube. Google PIAB vacuum generators that work using compresed air. Same principle.

Wipers dont work well at wide open throttle. But at partial throttle while cruisng at any given speed there is ample manifold vacuum to make the wipers swipe.

OK, I'll give you the vacuum advance, I've used compressed air to siphon gas so I understand the principle of vacuum generators and the draft tube, my mistake.

At part throttle there is ample vacuum to operate the wipers, but you said "once the throttle butterfly opens manifold vacuum drops to near zero", I don't think near zero would allow wipers to operate.

[buds truck]

She's not a guy Don.

She's our Gold Country Fair Queen voted in by us hill folk.

We finally got us a purdy one this year compared to last years queen shown here.

MOM!!!!!!

[grey beard]

Gentlemen,

I'm confused. You guys speak of vacuum advance units as though they are miraculous high performance items that create added power. My own experience with them is that their only function is to offer added economy.

Consider this: half and three quarter ton trucks use a vacuum advance unit that is made to add 18 degrees of advance to the ignition event. The centrifugal advances in these same distributors add an additional 18 to 22 degrees advance, for a total of nearly 40 crankshaft degrees advance at 2850 rpm.

MoPar trucks over three quarter ton in size offer the same centrifugal advance curve - 20 degrees total advance - but do not even use a vacuum advance unit. This is also true of nearly all industrial and ag applications for these L6 engines. Traditionally, vacuum advance units are used only on vehicles that drive in stop-and-go traffic conditions where part-throttle driving is common. In heavier trucks, full-throttle driving is the norm, yet they produce nearly identical horsepower and torque as the smaller units that use a vacuum advance unit.

Taking what you say here about extra power coming from the added advance provided by the vacuum advance, would it not follow that heavier trucks would also benefit from this extra shot of advance at the right time? If they lug heavy loads at wide open throttle, why not give them that extra avance, as well?

These specs come from the electrical section of the truck shop manual. Sorry, but I do not have an automobile manual for comparison, but common sense says the advance profiles for them will be similar to the half ton trucks.

Sometimes I don't understand everything I know about this stuff.