How good is 4.9 L (300 CID) I6 engine?
#61
#63
crsmiffy from Australia made reference a couple of pages back to another six that by accounts I've heard would give our 240/300 real competition for "best six": the Chrysler hemi six designed and built in Oz. A shame they never made it up here. Had they been available, you wouldn't hear American Mopar fans talk so much about the Slant Sixes.
Superduty, if you talk to long-established machine shops you'll get a slightly different take on the 300 than what you've gotten here so far. The failure of the phenolic cam gear is not so bad. First, they really do go quite a long time, and then when they do shear off teeth and you get towed home, you learn that both 240 and 300 are "non-interference" engines, meaning that you didn't bend any valves when the cam stopped turning, and all you need to get on the road again is a new gear and an oil and filter change.
The problem the shops will tell you about is that high-time 300s crack/break pistons, and they've seen a lot of these, even in engines which had been running, the owner unaware of the situation. When the 240 was stroked to make the 300, the rod-length-to-stroke ratio got a lot worse (i.e. "short rods"), adding a lot of side-loading on the skirts of cast aluminum pistons with a steel insert for expansion control. Frenchtown Flyer, an ex Ford engineer, will tell you this was a sub-optimal combination.
The other things for which the 300 might be faulted include the low compression and inefficient smog heads that came on them up until about the time of the EFI version. And the restrictively small valves and ports. The cheapo manifolds on the pre-EFI motors.
No, the 300 is not without issues. But the thing is, IF you are willing to build a 300 with the appropriate upgrades in these few areas, it becomes a wonderful engine! Tough as nails, practical street torque, inherently smooth-running, fuel-efficient, compact, simple, light; with the easy, cheap upgrades, the 300 is one of the keeper engines of all time.
Superduty, if you talk to long-established machine shops you'll get a slightly different take on the 300 than what you've gotten here so far. The failure of the phenolic cam gear is not so bad. First, they really do go quite a long time, and then when they do shear off teeth and you get towed home, you learn that both 240 and 300 are "non-interference" engines, meaning that you didn't bend any valves when the cam stopped turning, and all you need to get on the road again is a new gear and an oil and filter change.
The problem the shops will tell you about is that high-time 300s crack/break pistons, and they've seen a lot of these, even in engines which had been running, the owner unaware of the situation. When the 240 was stroked to make the 300, the rod-length-to-stroke ratio got a lot worse (i.e. "short rods"), adding a lot of side-loading on the skirts of cast aluminum pistons with a steel insert for expansion control. Frenchtown Flyer, an ex Ford engineer, will tell you this was a sub-optimal combination.
The other things for which the 300 might be faulted include the low compression and inefficient smog heads that came on them up until about the time of the EFI version. And the restrictively small valves and ports. The cheapo manifolds on the pre-EFI motors.
No, the 300 is not without issues. But the thing is, IF you are willing to build a 300 with the appropriate upgrades in these few areas, it becomes a wonderful engine! Tough as nails, practical street torque, inherently smooth-running, fuel-efficient, compact, simple, light; with the easy, cheap upgrades, the 300 is one of the keeper engines of all time.
#64
The company I work for had an 84 f250 flatbed with a 300. That engine had over 500,000 miles on it and was still running when it was sold.Maybe doesnt sound that impressive until you realize that there may have been 150 different people driving it through the years that didnt really care what they did to it.
#65
#66
Still, there's plenty of power in these engines. I have a 3.00 rear with 32" tires and there's still plenty of oomph for me.
#67
Quote:
Originally Posted by Mike Christiansen
"Few people think past the power of the engine. While the tranny and differential can be easily tweaked to your needs. For starters, don't waste your time with 3.08 ring gear unless you enjoy a gutless wonder. 3.55 w"
AbandonedBronco
Moderator
"A lot of truth to this. Have had two Broncos with 300s. One was a 3.00 rear and the other a 3.55. Granted, both had a 4bbl and exhaust upgrade, so that helped. The 3.55 would set you back in your seat while the 3.00... not quite so much.
Still, there's plenty of power in these engines. I have a 3.00 rear with 32" tires and there's still plenty of oomph for me."
I have a '81 F100 with the SROD (3 sp + OD4th) and factory 2.46 and it is a dog with a big D! The rear end is going to 3.50 this week (Mine came with a 9" rear) so expect a big pickup in power, and it will lay the foundation for actual engine improvements coming up.
Love this engine; like has been said before, the defects are well known but so are the fixes, but even stock they run for a long time. Hard to beat the reliability and all around use of these.
Originally Posted by Mike Christiansen
"Few people think past the power of the engine. While the tranny and differential can be easily tweaked to your needs. For starters, don't waste your time with 3.08 ring gear unless you enjoy a gutless wonder. 3.55 w"
AbandonedBronco
Moderator
"A lot of truth to this. Have had two Broncos with 300s. One was a 3.00 rear and the other a 3.55. Granted, both had a 4bbl and exhaust upgrade, so that helped. The 3.55 would set you back in your seat while the 3.00... not quite so much.
Still, there's plenty of power in these engines. I have a 3.00 rear with 32" tires and there's still plenty of oomph for me."
I have a '81 F100 with the SROD (3 sp + OD4th) and factory 2.46 and it is a dog with a big D! The rear end is going to 3.50 this week (Mine came with a 9" rear) so expect a big pickup in power, and it will lay the foundation for actual engine improvements coming up.
Love this engine; like has been said before, the defects are well known but so are the fixes, but even stock they run for a long time. Hard to beat the reliability and all around use of these.
#68
As you know, here in Australia we stuck'small block' 200-250 cu i with the latter in trucks. And then on to the 'Barra' EFI L6 in falcons.
Had a 408 in the 351M/400 configuration in a 1978 F-100. Run on straight propane with a 224 litre capacity. But heavy on the front end, especially with manual steering, and with full length headers bloody noisy.
After joining this forum discovered a small group of devotees in Aus to the 300. Well, to cut a long story short, here is the result.
The F-100 gives up nothing on bottom end and is a joy to drive. And the space to work on the motor is incredible. Oh, and I can have a conversation in the cab while driving now.
So impressed am I by the 300 that now I have another one to recondition and put into an XB Falcon to replace the tired 250 'small block' the car currently has in it!
#70
I got a 93 f150 with the 300. I traded my dad my 07 silverado with less miles in with hopes to restore it. Though the engine itself only needed a few leaks fixed, it has been the most reliable truck I've ever owned. While I changed the distributor and for got the oil pump rod thay goes in the bottom and ran it a good 15 minutes with no oil, started to tap and that's when I realized what I done wrong, fixed it and I was completely shocked to see it running that long with no oil.
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