Crane 500511 or 503901

pmuller9

2K+
VIP Member
Supporter 2018
If a dead spot below 1000 rpm shows up in granny low first gear and the OP wants it eliminated then he is going about it the right way.
The only time he sees the dead spot is when starting from a stand still.
The 4.10 gear may help just like starting out in first gear instead of second but it still won't make it go away.
 

Wesman07

Famous Member
Supporter 2020
Exactly.

Starting off in first can be tricky. The gas to clutch ratio has to be perfect. If not, it will either jump off the line or bog for a second and then go. There is a 100 rpm sweet spot.

It is a accually much easier to start off with a load because it is more predictable.
 

jason832

Well-known member
My 85 has 3.55 gears and 35 inch tires, and a np435. It already turns over 2000rpm on the highway, more than enough. The np435 has enough gearing to get you going fine.

With factory efi I don't know what the computer will tolerate or how much power the stock everything else can even support. Google around for "ford 300 efi cam" there are a few designed to run fine with the efi I believe.
 

old28racer

Famous Member
Why would I buy a Crane 503901 over an Egin RV torque cam $137 Crane / $106 Elgin

Crane Adv Dur Int -- 260 Exh -- 272 Elgin Adv Dur Int -- 280 Exh -- 290
Dur @ .050 Int -- 204 Exh -- 216 Dur @ .050 Int --204 Exh -- 214
Lift Int -- .458 Exh -- .487 Lift Int -- .451 Exh -- .475

If it's just name?
 

pmuller9

2K+
VIP Member
Supporter 2018
old28racer":fyoomasv said:
Why would I buy a Crane 503901 over an Egin RV torque cam $137 Crane / $106 Elgin

Crane Adv Dur Int -- 260 Exh -- 272 Elgin Adv Dur Int -- 280 Exh -- 290
Dur @ .050 Int -- 204 Exh -- 216 Dur @ .050 Int --204 Exh -- 214
Lift Int -- .458 Exh -- .487 Lift Int -- .451 Exh -- .475

If it's just name?
See Post #11
 

Wesman07

Famous Member
Supporter 2020
tnab1970":3et7lb9n said:
Any update on the Crane 503901 camshaft performance?

The engine has around 250k on it, its healthy but getting old. My better judgement told me to save the cam for the new motor. So I just put in new timing gears, advanced the cam, injectors, and fixed what was broke, and put it back in the truck.

I plan on building a motor with a stock bottom end, cleaned up efi head, the 901 cam, larger injectors and some sort of fuel controller. A solid 200hp/300lbft in the 1,000 - 4,500 rpm range. The only problem is, my tired motor is never the "squeaky wheel".... so the project gets put on the backs burner while I fix everything else. Long live the 300 six!
 

Wesman07

Famous Member
Supporter 2020
For the record... advancing the cam did not cause any negative side affects. It did make the motor feel more "stout", like truck motors should feel. The motor does not need to work as hard to get the truck rolling, and is perfectly happy starting off at 900 rpm. The motor also likes to sit just below peak hp (3,200) when it's being worked, on long grades.
 

jason832

Well-known member
Wesman07":2kx83tiy said:
I plan on building a motor with a stock bottom end

Wesman07":2kx83tiy said:
A solid 200hp/300lbft in the 1,000 - 4,500 rpm range

Wesman07":2kx83tiy said:
Long live the 300 six!
I doubt it will live that long with stock pistons.

Pistons can be replaced easily. As long as the six of them are weight matched you don't have any balancing issues. Lighter ones will also help take some strain off the rods and rod bolts. I used the sealed power h519p and e-229k rings. They're cheap, weight matched when bought in a kit and are a great replacement for stock pistons.
 

jason832

Well-known member
I somewhat built the original 85, family inherited 300 in my truck. Stock never opened bottom end and it had about 120k KM. Only modifications were a 4 barrel, Clifford intake, and headers. Within a few months it lost most compression in one of the cylinders. That bottom end sits on my garage floor with a scratched cylinder.

Shortly after that I planned and did a full performance build from the ground up. The Frenchtown Flyer said that even a stock rebuild should get new pistons, let alone any performance build.

OP can build his motor how he wants, but I strongly recommended new pistons. They're cheap, don't require the engine to be rebalanced like a v8, and its the last thing in a motor you want to break, its the last part out and the first in.
 

guhfluh

Famous Member
Mine is also an 85 bottom end.

I wouldnt worry about an EFI bottom end with hyper pistons if it's good to start with. Swapping pistons in just because isn't an easy task, nor is machine shop work cheap. Only if the budget allows and you're starting with earlier cast pistons would I consider it.
 

THE FRENCHTOWN FLYER

Moderator
VIP Member
Supporter 2020
Supporter 2018
The later EFI engines with hypereutectic, strutless pistons are vastly superior to the problem-prone cast strutted pistons of the carbed era. I rarely take apart a carbed engine where I don't find at least a couple with cracked skirts. While every engine with cracked or broken skirts will not have a catastrophic failure the odds are high enough that I would consider a piston upgrade to the now commonly available hypereutectic units.
 

old28racer

Famous Member
FTF do you think the 1992 EFI 300 I picked up had OEM Hyper pistons? They look real good but they only had 1000 or so miles on them in a farm truck before the fiber cam gear spit some teeth. Picture below.

<img src="https://image.ibb.co/nQwS9k/300_Motor_13.jpg" alt="300 Motor 13" border="0" />
 
Top