Main IndexAuto Repair Home Search Posts SEARCH
Who's Online WHO'S
Log in LOG

Search Auto Parts

47 DeSoto

  Email This Post

New User

Sep 7, 2010, 9:07 PM

Post #1 of 5 (2443 views)
47 DeSoto Sign In

Hey! my friend has a '47 or '48 DeSoto. the car has been sitting for about a year. it's all orig. we cannot get the car to start. it does have low compression. 70,50,35,35,50,60. we mostly want to get the car started before winter. can we push start the car? it has the auto w/clutch. the engine turns over, sputters but won't quite take off. thanks wallybdesoto!

Veteran / Moderator
Sidom profile image

Sep 7, 2010, 11:36 PM

Post #2 of 5 (2436 views)
Re: 47 DeSoto Sign In

If those reading are accurate, there is no way this engine is going to run. You want a minimum of 100 lbs compression.

Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Sep 8, 2010, 8:12 AM

Post #3 of 5 (2420 views)
Re: 47 DeSoto Sign In

A maybe to start this if it can sputter now it just might work:

Since it's been sitting and probably 6v system which cranks slow to begin with you need to get it to run for the old metallurgy of rings and things to warm up and reset. Doing some serious guessing as I don't know and don't think you do if the ran a year ago or whatever?

I'd put the smallest squirt of light oil meaning not enough to lock up a cylinder. Just a squirt. Just crank it with no choke a couple rounds. Use a fair amount of real starting fluid in intake.

Then if all legal and safe where you are, tow it to some speed like 15-20 mph - that or a good hill. Then do the pop the clutch trick and it should crank the engine fast enough to get much higher compression for the moment and once if it will run things would loosen up and let it run to clear out the oil and clean the plugs fouled by that trick.

Bet it will run but who knows? If it does and can warm up and smooth out bet it will start on its own later and you can do much more accurate diagnosing from there to make it actually run well.

Seems like there's a shortage of info on the thing so again who knows? I've forced some pretty old stuff pulling some tricks.

Just know that none of the oldies like the fuel sold today which becomes it's own problem for later to deal with if this is a go at all,



Jul 21, 2011, 8:24 AM

Post #4 of 5 (2160 views)
Re: 47 DeSoto Sign In

I have several old Mopar flatheads, Used patience, lots of starting fluid, a very good 12 volt battery (no it don't hurt the starter just use it to jump the 6 volt and beware of battery explosion), Make sure of an ample supply of gasoline to carb. When it finally starts if it doesn't smooth out after a few minutes, check compression again. If compression doesn't improve your valves are sticking. Remove head and free valves, (sometimes Marvel Mystery oil works poured into sparkplug holes and crank with plugs out). These are good, tough engines. Fantastic machines.

Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Jul 21, 2011, 2:37 PM

Post #5 of 5 (2139 views)
Re: 47 DeSoto Sign In

This thread is older than dirt - get a life,


  Email This Post

Feed Button

Search for (options) Privacy Sitemap