​​​​​​​​​​​​​

Durant Motors Internet Forum

Our Purpose

  Preserve the automobiles manufactured by the Durant Motor Company, provide enjoyment for each member with meets, tours & technical assistance.


This forum is provided by the Durant Motors Automobile Club located at durantmotors.org





How to Add Pictures 

General Discussion Forum
Start a New Topic 
Author
Comment
Were there different camshaft designs for the Durant 4 cyl engine?

Have a car in the restoration shop, And the rebuilt engine runs as if it has a huge race cam in it.... Very rough, yet consistent idle just as a race car sounds, heavy lope until around 1500 rpm... have tried correct tillotson and a rebuilt zenith carb, both are the same, not a fuel issue, the car does not run rich at idle, and is not lean, pulled the timing cover and verified correct cam timing, even tried one tooth more and one tooth less... ran terrible unless at the correct setting.. in gear under a load, run smooth yet has no power at all, wont hold thirty even on an almost flat road... could there have been an industrial cam for these engines to operate industrial water pumps or the like? does anyone have any suggestions? Thanks in advance....

Where Are You From? Clermont Florida

Do You own a car built by Durant? 1929 Rugby

Re: Were there different camshaft designs for the Durant 4 cyl engine?

Hi Charles,

It sounds to me that you are on the right track, and what may have happened is that someone sent the cam out to have it ground and asked to have it sweetened up a bit and it came back a full race cam (this happened to me on a 6 cylinder Contenental) hard starting, poor running and barely enough power to run itself.....What I might suggest is this, if you don't have a bad vacuume leak or blocked exhaust or something of the sort is to do a rough check to see how radical the grind is on your cam...You seam quite knowledgable so I'll be brief...Use your front pulley as a degree wheel, Locate #1 piston to top dead center exhaust stroke (can view piston through spark plug hole) Make a mark on pulley and an adjacent mark on timing cover, next turn engine backwards a bit then slowly turn engine in direction of rotation until #1 exhaust valve just has stem clearance (maybe .004 feeler gauge) make another mark on timing cover aligned with pulley mark...Next, turn engine on past T.D.C. mark and watch #1 intake stem clearance just tighten up or (tight .004 feeler gauge), make another mark on timing cover in alignment with pulley mark....Next, measure distance between lines on timing cover between T.D.C. and ex. closing and in. opening marks...Measure diameter of pulley and do the math If the grind is stock it shouldn't be over 2 to 4 degrees on each side of T.D.C.... If it is up around maybe 20+ Then I think it is starting to get radical, If this is the case I might suggest calling Delta Cam in Tacoma and tell them what you have found, they can run a profile on your cam and can tell you exactly what you have, they are excellant at repairing other cam shops mistakes and are very reasonably priced as well...http://deltacam.com/tech.php

Where Are You From? Leavenworth, WA / Yuma, AZ

Do You own a car built by Durant? Yep

Re: Were there different camshaft designs for the Durant 4 cyl engine?

I forgot to mention, you don't have to do the math...Do a computer search for "Degree wheel image" and a number of degree wheels will pop up, click on one you like, on my monitor they come up at about 6 inches diameter...you need to print an image to the exact diameter of your pulley, then you can take your measurements and apply them to the degree wheel using the T.D.C. or zero mark as a common reference point, as best as you can bend your tape measure to follow the radius to make your measurements....Count the degrees between your transferred measurements and there you have it.

You may find a better method of doing all this, you may also want to place all marks on your pulley and just the T.D.C. mark on timing cover but whatever works best, it makes the same difference...Anyway, that's my two cents, but I'm sure you get the idea.

Where Are You From? Leavenworth, WA / Yuma, AZ

Do You own a car built by Durant? Yes , several

 

The Durant Motors Automobile Club