High Revs/Shorter Life?

King Snake · 08-04-2000, 11:42 AM

I saw a friend of mine on the road the other day driving his old Chevy truck with a bad*** 350 and decided to do a flyby. I talked to him later and he asked me what RPMs I was running when I passed and I told him it was around 5000. He said that if I keep reving my engine like that I would be rebuilding the lower end before the car had 50,000 miles. I explained that these DOHC engines like to rev and that he was wrong. But actually, it must have an impact on the longevity of the motor. The 4.6s haven't been around long enough to stand the test of time. But I will continue to drive the car like it was meant to be driven, and as long as I keep the revs below redline and change the Mobil 1 synthetic every 3000 miles the engine should last 150,000 miles. What do you guys think?

------------------
'97 Cobra, K&N, Rio Red

[This message has been edited by King Snake (edited 08-04-2000).]

97snakedriver · 08-04-2000, 12:55 PM

Driving a car hard always adds to the wear and tear, but the DOHC is a very strong and reliable engine and is designed to rev. There are all ready Cobra engines in the 100,000+ mile range with no real patterns of maintance problems. The Lincoln version of the engine has been around since 93 with out any real problems either. The only time people seem to run into trouble is with botched installs or bad tuning with superchargers.

Have you ever wondered why the DOHC is so freaking big? Almost as big a Boss 429 big block? Its because those suckers are built. Craw under the car and check out the ribbing cast into the block. It pretty cool. The block is cast by and Italian company called Teksid, which specializes in high perfomance street and race car blocks. The weakest peice appears to the pistons. They are very good with dealing with presure, but they really can't stand any detonation at all. But that's easy enough to avoid as long as you don't fall into the trap of running the on the absolute ragged edge of tuning to trying to squeeze out that last 5 hp. I've never heard of any one throwing a rod in one of these engines. The crank is an extremely good peice. Forged steel from a German company called Gerlach-Werke. I would love to see some one break that sucker. The main bearing caps are also 6 bolted. 4 though the top, and 2 cross bolts that go though side of the block and into the bearings. A very strong setup.

The Cobras also have a windage tray, crank wiper that works pretty well.

The old chevy truck 350s redline at something rediculously low, so 5000 probably sounded pretty fast.

As long as you take care of it, the Cobra engine will take a high reving beating for a long time and be just fine. On the other hand that T45 POS is a completely different story...

fixer · 08-04-2000, 11:11 PM

your buddy is thinking of his 350.

the 4.6 is,indisputably a high reving motor, as all overhead cam motors are.

even ford itself emphasizes this aspect in its advertisments. they wouldn't be encouraging people to bring the rpm's up unless the motor could, invariably, handle it.

no offense to your buddy, but it sounds like he has spent too much time in checker/shucks/kragen parking lots overhauling his 350 to know what the hell a dohc motor is, much less what it is capable of.

95GTS · 08-05-2000, 02:41 PM

97Snakedriver is right. Don't worry about the engine. But the T-45 is a POS. I just spent over $1000 on mine w/43000 miles on it cause a stupid little elbow looking thing on the 1-2 gear shift fork that slides up and down the shift rail broke. About the first half of that money was at a trans shop that screwed me royally in charging me $450 dollars to take the transmission out of the car and look at it and tell me the stuff that was wrong with it, which they were wrong. I took it to Ford and they diagnosed it correctly and fixed for another $473. And then there's the tow bill, and........ If any of you guys are in SW Missouri DO NOT take anything to All American Transmission in Joplin!! They will screw you good.
The T-45 is supposed to be a stronger trans than the T-5. If so, I'd hate to have a T-5. If I knew it would have cost me that much money I just would have bought another trans.

------------------
1996 Mustang GTS: 5-speed, K&N, removed air silencer, 3.73s, turndowns after stock H-pipe (no mufflers)

ASVTFordBoy · 08-07-2000, 10:46 AM

Agreed. The T-45 is a POS. My last one lasted about 4 months. Now it needs to be replaced again. The 3-4 Shift fork is completely gone. Obviously it can't handle the 4.6L DOHC.

97snakedriver · 08-07-2000, 10:51 AM

I'm saving my pennies for either a T56 or a Tremac.

King Snake · 08-07-2000, 11:08 AM

Thank all for the feedback. It sounds like the DOHC may be as tough as I had thought.

97Snakedriver, have you had any problems with your T45? Also, what would it cost (est) to replace the T45 with a Tremec?

------------------
'97 Cobra, K&N, Rio Red

97snakedriver · 08-07-2000, 01:10 PM

My tranny can be a little off untill it warms up, which is sign of bad syncros. Rush shifts, especially 1-2.

5 speed Tremacs start in the $1500ish neighborhood for a good one, and go up from there. I think I've seen some T56s (6 speed) for about $2000-$2200.

08-04-2000, 11:42 AM	#1
King Snake Registered Member Join Date: Jan 2000 Location: Warner Robins, GA, USA Posts: 210	High Revs/Shorter Life? I saw a friend of mine on the road the other day driving his old Chevy truck with a bad*** 350 and decided to do a flyby. I talked to him later and he asked me what RPMs I was running when I passed and I told him it was around 5000. He said that if I keep reving my engine like that I would be rebuilding the lower end before the car had 50,000 miles. I explained that these DOHC engines like to rev and that he was wrong. But actually, it must have an impact on the longevity of the motor. The 4.6s haven't been around long enough to stand the test of time. But I will continue to drive the car like it was meant to be driven, and as long as I keep the revs below redline and change the Mobil 1 synthetic every 3000 miles the engine should last 150,000 miles. What do you guys think? ------------------ '97 Cobra, K&N, Rio Red [This message has been edited by King Snake (edited 08-04-2000).]

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08-04-2000, 12:55 PM	#2
97snakedriver Registered Member Join Date: May 1999 Location: Blacksburg, VA Posts: 1,526	Driving a car hard always adds to the wear and tear, but the DOHC is a very strong and reliable engine and is designed to rev. There are all ready Cobra engines in the 100,000+ mile range with no real patterns of maintance problems. The Lincoln version of the engine has been around since 93 with out any real problems either. The only time people seem to run into trouble is with botched installs or bad tuning with superchargers. Have you ever wondered why the DOHC is so freaking big? Almost as big a Boss 429 big block? Its because those suckers are built. Craw under the car and check out the ribbing cast into the block. It pretty cool. The block is cast by and Italian company called Teksid, which specializes in high perfomance street and race car blocks. The weakest peice appears to the pistons. They are very good with dealing with presure, but they really can't stand any detonation at all. But that's easy enough to avoid as long as you don't fall into the trap of running the on the absolute ragged edge of tuning to trying to squeeze out that last 5 hp. I've never heard of any one throwing a rod in one of these engines. The crank is an extremely good peice. Forged steel from a German company called Gerlach-Werke. I would love to see some one break that sucker. The main bearing caps are also 6 bolted. 4 though the top, and 2 cross bolts that go though side of the block and into the bearings. A very strong setup. The Cobras also have a windage tray, crank wiper that works pretty well. The old chevy truck 350s redline at something rediculously low, so 5000 probably sounded pretty fast. As long as you take care of it, the Cobra engine will take a high reving beating for a long time and be just fine. On the other hand that T45 POS is a completely different story...

08-04-2000, 11:11 PM	#3
fixer Registered Member Join Date: Aug 1999 Location: mesa,az,usa Posts: 457	your buddy is thinking of his 350. the 4.6 is,indisputably a high reving motor, as all overhead cam motors are. even ford itself emphasizes this aspect in its advertisments. they wouldn't be encouraging people to bring the rpm's up unless the motor could, invariably, handle it. no offense to your buddy, but it sounds like he has spent too much time in checker/shucks/kragen parking lots overhauling his 350 to know what the hell a dohc motor is, much less what it is capable of.

08-05-2000, 02:41 PM	#4
95GTS Git jiggy Join Date: Oct 1999 Location: MO USA Posts: 865	97Snakedriver is right. Don't worry about the engine. But the T-45 is a POS. I just spent over $1000 on mine w/43000 miles on it cause a stupid little elbow looking thing on the 1-2 gear shift fork that slides up and down the shift rail broke. About the first half of that money was at a trans shop that screwed me royally in charging me $450 dollars to take the transmission out of the car and look at it and tell me the stuff that was wrong with it, which they were wrong. I took it to Ford and they diagnosed it correctly and fixed for another $473. And then there's the tow bill, and........ If any of you guys are in SW Missouri DO NOT take anything to All American Transmission in Joplin!! They will screw you good. The T-45 is supposed to be a stronger trans than the T-5. If so, I'd hate to have a T-5. If I knew it would have cost me that much money I just would have bought another trans. ------------------ 1996 Mustang GTS: 5-speed, K&N, removed air silencer, 3.73s, turndowns after stock H-pipe (no mufflers)

08-07-2000, 10:46 AM	#5
ASVTFordBoy Registered Member Join Date: Aug 2000 Location: Baytown Posts: 1	Agreed. The T-45 is a POS. My last one lasted about 4 months. Now it needs to be replaced again. The 3-4 Shift fork is completely gone. Obviously it can't handle the 4.6L DOHC.

08-07-2000, 10:51 AM	#6
97snakedriver Registered Member Join Date: May 1999 Location: Blacksburg, VA Posts: 1,526	I'm saving my pennies for either a T56 or a Tremac.

08-07-2000, 11:08 AM	#7
King Snake Registered Member Join Date: Jan 2000 Location: Warner Robins, GA, USA Posts: 210	Thank all for the feedback. It sounds like the DOHC may be as tough as I had thought. 97Snakedriver, have you had any problems with your T45? Also, what would it cost (est) to replace the T45 with a Tremec? ------------------ '97 Cobra, K&N, Rio Red

08-07-2000, 01:10 PM	#8
97snakedriver Registered Member Join Date: May 1999 Location: Blacksburg, VA Posts: 1,526	My tranny can be a little off untill it warms up, which is sign of bad syncros. Rush shifts, especially 1-2. 5 speed Tremacs start in the $1500ish neighborhood for a good one, and go up from there. I think I've seen some T56s (6 speed) for about $2000-$2200.