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48ply1stcar

ANSWERED Spring test drive - I want more top end

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After two years of putzing with my rebuilt 230 (56 / 53) flathead, I feel like run out of engine before I should. Took it out for a early spring drive to check the brakes and extended the ride down the highway. I get to about 60 (inaccuarate speedometer) with my new to me 2000 Cherokee rear axle. When I push on the accelerator the engine starts to bog down, not bad just doesn't accerate any more. I have a 4 inch air cleaner - not enough air? Starts great, runs well until high speed, - will retarding or advancing the spark help? I'm continuing to try little things.

Additionally, I have replaced the fuel lines, new fuel pump and added an electric pump in front of the fuel tank.  Electric fuel pump doesn't appear to make a difference.

 
 
 
 

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What's thefinal drive ratio in the Jeep did?  Find a level stretch and do a wide open throttle pull in high gear.  Time it if you can.

Edited by greg g

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I have no such issue with a 4" air cleaner. Stock rear so the engine is awfully busy at 60 (55 is a better cruise speed for it)  but it will go faster no problem. 

I am running electronic ignition ,not points and the yf carb is a little better at higher speed but the BB didn't fall flat either. 

 

Just throwing darts here....

Is your vacuum advance known working? How about any possible vacuum leaks?

 

I will say it ran as you describe when the vacuum actuator was bad ( torn diaphragm) causing a simultaneous leak and lack of advance.

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27 minutes ago, greg g said:

What's thefinal drive ratio in the Jeep did?  Find a level stretch and do a wide open throttle pull in high gear.  Time it if you can.

I went with a 355 Chrysler 8 1/4 from a 2000 Cherokee.

Going to try advancing timing tomorrow.

Edited by 48ply1stcar

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Get rid of that 4" air filter first..put a larger filter on that engine.

Then make sure the ratio is not too stiff.🙂

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My car has the 411 gear set but I did put an od in before last driving season.  The OD drops my cruising rpm by 900 or so at 60 ish. Even with the OD engaged it will scoot from 50 to 70 well.

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Someone mentioned vacuum advance. I was wondering for my own understanding: I thought vacuum advance initially activated early stages of timing advance. Due to opening of the  throttle, initially causing high vacuum. Then as the engine sped up, centrifugal weights took over the breaker plate advance. Therefore top end engine speed would be more effected by centrifugal advance. As opposed to vacuum advance.  Am I understanding the theory correctly? Thx. 

Edited by keithb7

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41 minutes ago, keithb7 said:

Someone mentioned vacuum advance. I was wondering for my own understanding: I thought vacuum advance initially activated early stages of timing advance. Due to opening of the  throttle, initially causing high vacuum. Then as the engine sped up, centrifugal weights took over the breaker plate advance. Therefore top end engine speed would be more effected by centrifugal advance. As opposed to vacuum advance.  Am I understanding the theory correctly? Thx. 

Wide open with no load yes, mechanical will take over entirely. High-mid @(3kish) at any partial throttle the vacuum still adds advance.

Put a load on it and it doesn't want to rev during that stage where vacuum would be adding to it so wot doesn't have the necessary rpm to take over completely.

 

Or I guess to put it better, stomp on it and vac drops off, accelerate normally past 60 you'll still have vac.

Though the lean condition from a torn diaphragm probably hurt more.

 

Edited by 50mech

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1 hour ago, keithb7 said:

Someone mentioned vacuum advance. I was wondering for my own understanding: I thought vacuum advance initially activated early stages of timing advance. Due to opening of the  throttle, initially causing high vacuum. Then as the engine sped up, centrifugal weights took over the breaker plate advance. Therefore top end engine speed would be more effected by centrifugal advance. As opposed to vacuum advance.  Am I understanding the theory correctly? Thx. 

That condition actually drops the vacuum in the intake and results in no advance.  Those units using venturi vacuum, ported above the throttle plates will have no advance at idle.  Both above and below throttle ports will build vacuum peed increases up to the max for a given load and speed.    You're correct in the high speed being more affected by centrifugal.  With wide open throttle in  a high speed run, there would be little if any vacuum advance.

 

Under light load and moderate speeds vacuum advance will provide the most increase.

 

If anyone is thinking Fords abomination of carb source switching, vacuum only advance, the above doesn't apply.

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I do have a new vacuum advance and I have totally disassembaled the distributor cleaned and lubed it.  Next nice day I'm goining to advance change the timing to 2 - 4 degrees Before Top Dead Center.  Maybe it's time for electronic ignition.

 

Edited by 48ply1stcar

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And after a test drive with the refurbed carburetor, try running w/o the air cleaner to see if that changes things.  Do one change at a time so's in the end you discover what the fix is/was. 

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4 minutes ago, mrwrstory said:

And after a test drive with the refurbed carburetor, try running w/o the air cleaner to see if that changes things.  Do one change at a time so's in the end you discover what the fix is/was. 

Right.  Thanks for the input.  Timing, Air filter (Many have been negative toward the 4 inch filter.) I just think it's the "4 inch thing that scares them"

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I would suggest you get rid of the points, install a Pertronix with one of their Flame Thrower coils. A new vacuum advance might be a good idea also. If your car is still 6v, use the 12v coil. If you question this application call Pertronix, ask them their recommendations. That's what I did on a 53 Pontiac 6v neg ground that I had.

I have used Pertronix ignitions in many vehicles during the past 20 + years.

You might of shot yourself in the foot with the Jeep 3.55.1 rear end. that ratio is a little high for a stock engine. The 3.55 works good in a Jeep Cherokee, however, it has a 4 spd AO trans behind the 4. Lt engine that will down shift to 3rd gear when you step on it. Wm.

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3 minutes ago, blucarsdn said:

I would suggest you get rid of the points, install a Pertronix with one of their Flame Thrower coils. A new vacuum advance might be a good idea also. If your car is still 6v, use the 12v coil. If you question this application call Pertronix, ask them their recommendations. That's what I did on a 53 Pontiac 6v neg ground that I had.

I have used Pertronix ignitions in many vehicles during the past 20 + years.

You might of shot yourself in the foot with the Jeep 3.55.1 rear end. that ratio is a little high for a stock engine. The 3.55 works good in a Jeep Cherokee, however, it has a 4 spd AO trans behind the 4. Lt engine that will down shift to 3rd gear when you step on it. Wm.

I've been thinking Pertronix for a long time, but I often think I am just throwing parts at it for the last 25 years.  As far as the 3.55, stock is either 3.9 or 4.11.  I love the upgrade to the brakes and the new driveshaft.

 

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I dislike Petronix and other drop in style ignition swaps simply because if it fails you are stuck till parts arrive form somewhere else.

 

I am in the middle of swapping in a /6 distributor along with a Ford TFI coil and GM HEI module.  All parts I can get just about anywhere.

 

 

 

 

 

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I've been using a 6v positive ground pertronix in my '39 coupe for 4 years and 30,000 miles later still no issues.  I drive this thing 30 miles each way to work a day in 60 - 70 mph traffic no problem.  Only time my car ever died was with points.  With pertronix you never have to adjust timing again either.  I use a $20 bwd E5 6v coil from autozone.  I run the stock 3.9 rear end and no overdrive with my 218.

Edited by Polsonator2

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23 minutes ago, Polsonator2 said:

I've been using a 6v positive ground pertronix in my '39 coupe for 4 years and 30,000 miles later still no issues.  I drive this thing 30 miles each way to work a day in 60 - 70 mph traffic no problem.  Only time my car ever died was with points.  With pertronix you never have to adjust timing again either.  I use a $20 bwd E5 6v coil from autozone.  I run the stock 3.9 rear end and no overdrive with my 218.

I think I finally, got talked into Pertronix,  Stay safe out there in Seattle.  Maybe I can see yoiur car next time I visit the grand kids in Vancouver WA.

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One last thing though that is a negative for pertronix, i am not able to get my 6v westach tachometer to be able to work with it. There are other threads here about that discussion. I was never ever able to get it to work but some may have had success and can chime in here.

Edited by Polsonator2

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"Air filter (Many have been negative toward the 4 inch filter.) I just think it's the "4 inch thing that scares them"

When I was 16 back in 1968 I installed a 

"COOL" looking or so I thought 4" little air filter on my hot rod 1951 Cranbrook with 12" tall JC Whitney rear spring shackles...that was another stupid thing to do.

Anyway after a few months after I put it on that cool looking little chrome filter on I noticed the car wouldn't do 30 MPH in 1st gear and bogged out above 45 ....took awhile to figure out being dumb and 16 but I figured it was the air filter plugged up not the "Mighty Mallory"

dual point 3 lobe cam distributor...ha ha🥴

Now....

I have a little 12 HP single cylinder Tecumseh Massey Fergusen tractor that runs a 3"X6" air filter element as factory design...it lasts maybe 2 years max on my tractor and draws in 1/10  or less air volume than a 218/230.

Hmmm....

A engine needs plenty of air to breath...

Any restriction and mileage goes to pot as does available power.

But I have to say those little 4" chrome filters are cute.

Just saying.

 

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If the 4" air filter is the culprit. I just stacked two 4"ers together. You just need a longer threaded rod to attach the cap. Might be a

cheap and easy fix.

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2 hours ago, tom'sB2B said:

If the 4" air filter is the culprit. I just stacked two 4"ers together. You just need a longer threaded rod to attach the cap. Might be a

cheap and easy fix.

10 mile test, Changed timing no difference.  At the halfway point I removed the air cleaner no difference.

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