Griff in Fairbanks wrote:


I was wondering that but didn't have enough info. I supposed they rejetted it but the size of venturis can't be changed.

It's probably good to assume what works on a big block won't work on a small block and vice versa.

All the parts have to work together ... and need to suit the application and use.

I've seen too many people make a big change in one area and wonder why their vehicle suddenly runs crappy instead of better. Likewise, I've seen guys build engines suitable for stock car races and are "less than impressive" while profiling around town.

DRTDEVL wrote:

Mine came with a ThermoQuad already, so that should help. I seem to remember my grandfather saying he got about 10 mpg, but he never drove over 45. LOL

toedtoes wrote:

I know when I rebuilt my 360, I put in a new 4bbl carb (it had a rebuilt 2bbl). That first trip out, a friend with a 440 was joining me. He couldn't keep up with me.

DRTDEVL wrote:

My contractor lives in a 73 Dodge MH with a 360 and the 2245 Holley. I was wondering about that on his, too (I looked at it to see what's wrong since it quit running after the last parking, the float is stuck and flooding everything out). I would assume his has no guts uphill, whereas I can definitely hear the secondaries kick in on mine going uphill or leaving the stoplight briskly.

StingrayL82 wrote:

I think what renders it useless on the motorhome is the combination of the weight of the motorhome and gear ratio. I don't know if you've ever been up Pacheco Pass on Hwy. 152, but that poor Fireball just did not want to go up it. I was in 2nd gear most of the way up and even had to go down to 1st at one point, and I could only go 15MPH.

Griff in Fairbanks wrote:


Just woke up and haven't read all the overnight posts yet ... so, I may be repeating things here.

The 2245 is a two barrel so no secondaries. Just two constantly "on" barrels, like the primaries in four barrel carburetors.

What you were/are hearing it the transmission downshifting into second gear.

My carburetor expert, friend, and former boss died several weeks ago after a long battle with cancer. So, I have nobody I really trust for carburetor questions. Otherwise, I fire off an email to him and maybe point him to this discussion for his thoughts and experience. He's rebuilt hundreds and his large group of gearhead friends have probably used a hundred more.

Your contractor's 2245 may be dirty or gummed up.

Likewise, the cylinder rings/walls may be worn. (Unlikely in a motorhome.) One or more compression rings may be stuck. (More likely in a motorhome.) Or, the valves may be worn, dirty, or gummed up. All of this would mean cylinder blowby.

He may have one or more "collapsed" lifters.

The distributor might be mistimed or not getting enough vacuum.

All of this, individually or collectively, would lead to loss of power. This forces the operator to apply more throttle than he/she would need to with everything in good condition and working right.

The A727 automatic transmission has a linkage to the throttle linkage. Press the throttle far enough and the transmission linkage engages, causing the transmission to downshift.