225 upper rpm limit?

I had fat fingered my original post so after I read timgr's I went back and corrected it... Sorry about any confusion!

 

Thats my thoughts.
I once chased rich carburation around only to have my issues mostly resolved by a new exhaust.

I'm wondering what your spark plugs look like. Check them and see how it's burning.

 

New new new.

New exaust.
Cast iron manifolds no blockage.
Rebuilt carb tuned by vacume gauge.

Timing is about 9 btdc. best vacume also.
Hei. not new. new cap and rotor.
it purr's below 3000 rpm

Maybe plug wire's, there very old..

Cant find anything else wrong.

I can tell for certain the gearing is too tall.
Just lugs around. in third and forth

But the rpm thing is stumping me.

 

I believe it's 30

 

got a points dist you can stick back in it ?

 

How and when did this happen? Did you modify or adjust anything, or did you start it one day and it ran poorly out of nowhere?

 

what transmission are you running? out of curiousity

 

As far as gearing. I have 3.73 gears and 31" tires. With this combo I have pulled hay trailers with around 50 square bails several miles to my parents farm. That was around 3000lbs or more. My Jeep would pull that up the hills, it wouldn't stop it but it pulled it just fine. What you describe is definitely not normal. Heck I drive my Jeep regularly up a 8% grade that is about a 1 mile long. I can do that in 3rd (high) gear @40mph with 3 people in the jeep. It will still excelerate at that sped without downshifting.

You definitely have a problem somewhere.

 

Checked my rear diff tonight to be certain.
41 11 on the ring.

I bought my jeepster and drove it home slowly lol.
Been torn apart for 2 years.
Have now put 600 miles on it. in the last month.
From the minute i drove it down the block I knew it was geared to high.
It had and still does a 1 piece 44 narrow in the back with 3.73 gears and a trac lock.
the disc looked new init and so I didnt want to mess with it so the dana 30 front wide track I had was 4.10's so I rebuilt that with 3.73' as it need it anyway.
Put in a locksright which works good.
Refreshed the 225 as it had good compression all new gaskets.
Timing chain water pump oilpump rebuilt 231 carb, Hei ect.
Pulled the T86 and put in a Herm sm420.
Rebuilt the T20 case.
New dual exaust.
Tires are used BFG's M\T 32 x 11.5 's probably measure 31.

3rd gear is lugging at 45 and 4th is right out unless I want to do 60 or more.

So I take off in second and have to shift out but then cant drive around town with out kinda lugging it all the time.
It's like i need to be in between 2nd and 3rd to drive around town.

Everything is new or rebuilt except the plug wires and Hei gut's.

I will double check the advance and get new wires.

Was thinking the answer was 4.56's but you all have me woundering.
Sure dont want to take the axle's out again.

 

That’s just the nature of an SM420 there. There is a wide gap between 2nd and 3rd, 2nd=3.6:1 while 3rd=1.7:1.

http://www.novak-adapt.com/knowledge/sm420.htm

 

Corveeper hit that one dead on.

That's at least part of your crankshaft rpm concerns.
Not all transmissions were created equal and they must be synchronous with the total package.

Just for grins we must realize this has nothing to do with engine RPM and everything to do with crankshaft RPM.

 

Well it should be obvious from a terrestrial perspective that its not the D-225 that is spinning.

“THE CRANKSHAFT REVOLUTION”

The crankshaft revolution is simply a complete engine crankshaft rotation.
It is a visual and a tactile output, even audible.
Rotation is a movement around a specific reference point or physical axis.
A revolution is a complete rotation; a progressive motion of a body around an axis so that any point of the body parallel to the axis returns to its initial position while remaining parallel to the axis in transit and usually at a constant non elliptical distance from it.
In order to assist us in our conception of engine power output we will be referencing crankshaft velocity stated as Revolutions Per Minute (rpm).
We will not call it engine speed.