There are a few questions about my turbocharging the 8V-71 I'd like to clear up.
First-compression ratio-only the 53 series used 21:1. 71 series used 18.7:1 for non turbo, 17:1 for factory turbocharged, 15:1 for military turbocharged.
Since my engine was a 8V-71 non turbo, but with 18.7:1 two piece pistons with the tighter sealing transit bus rings, Don Fairchild thought it was alright to just turbo the engine.
I had a air to air intercooler custom made to mount in front of the radiator. Since the bus is 102", it had extra space in front of the radiator. Changed on the engine was bypass valve kit on the blower, throttle delay plumbed into the intake for turbo pressure, 65N increased to 7G75 injectors, bigger muffler, bigger air cleaner, 5 row straight fin to 6 row serpentine fin radiator (even so had to use misters), Series 60 11.1 turbo with waste gate set to 15psi. Power increased from 300hp and 800lb/ft torque to 375hp and 1125lb/ft torque-REALLY wakes up the 8V-71. Same mileage but much better performance. I had the turbo installed 10 years ago and have NO problems with it in 50,000 miles of driving. Good Luck, TomC
Lot of old wife's tales on turboing a 8v71 N/A engine ,if it has the later style rods turboing is not a issue with the 18:1 compression ratio on the N/A 8v71,the piping can suck though
with the power, can't figure whtmy you never changed rear axle ratio. Also why not a detuned 8V-92@400 hp. But shoulda, coulda, woulda.
On a V-drive, the big front vibration damper on the 8V-92 both gets in the way of the mounting of the engine and no way to mount the direct drive radiator fan. Detroit had a 7G80 injector version of the 8V-71TA at 400hp and 1200lb/ft torque. We kept it at 375hp and 1125 torque just to be conservative and have had no problem with it except not liking over 90 degree days. I just simply drive it like it used to letting it slow down on hills and down shifting. It was 108 through Las Vegas, but with the combination of light foot and misters never had to stop. I'm going to miss the 8V-71 sound. Good Luck, TomC
A 8v92 does good without the vibration damper as long as it is under 380 HP lot of N/A 8v92 didn't have a damper on the camshaft or crankshaft,Tom the turbo on the 3406 will make you a different sound to listen too I love that sound when the Cat engine is working hard
On a cool day, I can get 25psi out of my single turbo on the 3406B.
Quote from: luvrbus on July 06, 2022, 07:04:54 AM
A 8v92 does good without the vibration damper as long as it is under 380 HP lot of N/A 8v92 didn't have a damper on the camshaft or crankshaft,Tom the turbo on the 3406 will make you a different sound to listen too I love that sound when the Cat engine is working hard
Certainly none of us can deny how good those 71 and 92 engines sounded. However, given how much and fast engine technology changed over the years, one should never get sentimental over engines otherwise you'll end up being disappointed constantly. Not just buses but any vehicle. I loved the sound that the 4.6L V8 made in my '04 MERCURY GRAND MARQUIS. I finally traded it in back in November after over 17 years for a '21 NISSAN ALTIMA. This was long time coming and I knew that my next car would not have a V8 or V6 since like the old 71 and 92,
V8's and V6's were becoming less and less available for sedans. But fortunately, these newer 4 cylinder engines are not the same noisy and crude monsters of years ago. This 2.5L is smooth, low revving and doesn't make buzzy noises so engine type really isn't much of a factor for me and these days but it's about filling the power requirements anyway. I'm certainly not gonna complain about getting 35mpg or better compared to my previous car which got 20mpg give or take. :)
the same will be said once the fleet is changed to electric. Imagine how much manufacturers will save not having to emission certify engines and all the controls needed to obtain it, no more multispeed transmissions, transfer cases, differentials, drive shafts, heavy brake drums and rotors, complex exhaust systems.Would have been great to have forums when we switched the fleet from horses to cars and trucks, or from steam locomotives to diesel electrics.
Quote from: chessie4905 on July 07, 2022, 12:41:03 PM
the same will be said once the fleet is changed to electric. Imagine how much manufacturers will save not having to emission certify engines and all the controls needed to obtain it, no more multispeed transmissions, transfer cases, differentials, drive shafts, heavy brake drums and rotors, complex exhaust systems.Would have been great to have forums when we switched the fleet from horses to cars and trucks, or from steam locomotives to diesel electrics.
Let's see four to six contact points to the ground if each could handle 100HP....
I recently rented a KIA K5 4 door sedan. It had standard a tiny 1.6 liter turbo 4 cylinder with 180hp! It was stupid fast. I told the rental guys it was too fast to be a rental. But if you want a nice car for less than $30k, this is it. Good Luck, TomC
Back in the day - this would be considered stupid fast. The new EVs rolling out make this look like a snail. 0-60 under 3 seconds. This is as fast as supercars that start at 7 figures. Sorry to go OT
Quote from: windtrader on July 10, 2022, 12:18:24 PM
Back in the day - this would be considered stupid fast. The new EVs rolling out make this look like a snail. 0-60 under 3 seconds. This is as fast as supercars that start at 7 figures. Sorry to go OT
Yeah my eight year old EV does 0-60 in 4 seconds. But hey releasing your inter demon is only a couple OZ's of foot pressure. I will keep it until I really need the full time self driving to get around which I think will be a decade or so from now.
Quote from: TomC on July 10, 2022, 09:40:38 AM
I recently rented a KIA K5 4 door sedan. It had standard a tiny 1.6 liter turbo 4 cylinder with 180hp! It was stupid fast. I told the rental guys it was too fast to be a rental. But if you want a nice car for less than $30k, this is it. Good Luck, TomC
I rented one of those last year and yes, it really has good power for such a small engine. I know turbo's have long proven themselves on diesels but I would still skeptical about gasoline turbos over the long term. My '21 ALTIMA had a turbo available but the standard 2.5L more than powerful enough and will likely outlast the turbo version since it generates less heat and is very low revving.