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Old 07-10-2006, 07:01 PM   #1
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OK I believe Brazel's dyno numbers. But where is the hp/torq lost between the flywhweel and the tires? Brings up several other questions I've been pondering. Why not a rear mounted 8.1 like diesels? We've been fixing air to engine inadequicies, those high output deisels get air too. Could free up the front for some serious aerodynamics. Also just to know, I looked at the GM Goodwrench crate engine site to find the 8.1 replacement cost. What not listed!! But some very interesting 502 listings. Sure there are race engines but most interesting are carburated engines with much higher output than 8.1 (I've never been convinced about fuel injection) I've owned too many hi performance British roadsters not to know. Takes more routine tuning to keep in top shape but we like tweeking don't we. Just some thoughts and qustions. Comments?
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Old 07-10-2006, 07:01 PM   #2
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OK I believe Brazel's dyno numbers. But where is the hp/torq lost between the flywhweel and the tires? Brings up several other questions I've been pondering. Why not a rear mounted 8.1 like diesels? We've been fixing air to engine inadequicies, those high output deisels get air too. Could free up the front for some serious aerodynamics. Also just to know, I looked at the GM Goodwrench crate engine site to find the 8.1 replacement cost. What not listed!! But some very interesting 502 listings. Sure there are race engines but most interesting are carburated engines with much higher output than 8.1 (I've never been convinced about fuel injection) I've owned too many hi performance British roadsters not to know. Takes more routine tuning to keep in top shape but we like tweeking don't we. Just some thoughts and qustions. Comments?
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Old 07-10-2006, 08:07 PM   #3
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Only time I lost power was when it rained out or when I flip the CC switch to fast. Other than that its full steam ahead.
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Old 07-11-2006, 04:58 AM   #4
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<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by eandy:
OK I believe Brazel's dyno numbers. But where is the hp/torq lost between the flywhweel and the tires? </div></BLOCKQUOTE>The transmission consumes horsepower to turn over the gears so some HP is lost there. The addiitonal horsepower is then lost to the driveshaft, differentail gear set, axles, wheels and tires. Everything that is connected in-between the flywheel and the bottom of the tire comsumes horsepower because it generates a certain amount of heat or friction.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">(I've never been convinced about fuel injection) I've owned too many hi performance British roadsters not to know. Takes more routine tuning to keep in top shape but we like tweeking don't we. </div></BLOCKQUOTE>SU side draft cabruretors are like going to the dentist and having a tooth pulled without novacaine. Positive earth is another doozie! back in the day, MG owner.
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Old 07-11-2006, 06:42 AM   #5
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Monaco coach built 22 chassis with rear gas engines in the late 80's.That experiment didn't go very well.Lots of parts were not interchangeable & when they had failures,parts had to be custom made.

As for the 502 versus the 8.1L,the 502 will accept aftermarket intake manifolds & other parts,where the 496 GM injection only.
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Old 07-11-2006, 09:17 AM   #6
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<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by DriVer:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by eandy:
OK I believe Brazel's dyno numbers. But where is the hp/torq lost between the flywhweel and the tires? </div></BLOCKQUOTE>The transmission consumes horsepower to turn over the gears so some HP is lost there. The addiitonal horsepower is then lost to the driveshaft, differentail gear set, axles, wheels and tires. Everything that is connected in-between the flywheel and the bottom of the tire comsumes horsepower because it generates a certain amount of heat or friction.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">(I've never been convinced about fuel injection) I've owned too many hi performance British roadsters not to know. Takes more routine tuning to keep in top shape but we like tweeking don't we. </div></BLOCKQUOTE>SU side draft cabruretors are like going to the dentist and having a tooth pulled without novacaine. Positive earth is another doozie! back in the day, MG owner. </div></BLOCKQUOTE>

Not to mention Lucas electrics!!!!!!!!!!

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Old 07-11-2006, 09:46 AM   #7
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Thanks,good comeback. Mike, that was 20 yrs ago, but would like to know what problems were. I aware driveshafts would need to be modified or made from scratch. Not unusual. Tried to find info on axle seals at Dana site. No luck but noted huge range of rearends available. Still, if big hp/torq at tires improvement w/o the power loss? Begs the actual answer given the Monaco problems could be dealt with.
Aside from the obviously unaceptable level of detuning of the 8.1 from the factory, I'm happy with the engine tranny combo. There's always room for improvement w/o going stupid w/money. A rear engine configuration necessarily has to be less expensive on driveshaft alone. Still wondering.
BTW my roadsters were all big Healeys. The best w/60 overbore,pistons from England.Tranny rebuilt by a Jag mechanic moonlighting. Never found the top end. Pegged the speedo w/about 20% throttle left. Frontend got too light to persist. All my money went into best mechanical I could afford. Never even had good int. or paint. Yeah LUCAS. Couldn't afford new harness either, did like all others, paperclips and spare reel of wire, cross fingers. But RUN yeah!
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Old 07-11-2006, 10:12 AM   #8
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<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">A rear engine configuration necessarily has to be less expensive on driveshaft alone. Still wondering. </div></BLOCKQUOTE>
It certainly would be a lot SHORTER! Now here is a question I can't seem to figure out the answer: IF there were a rear facing engine, would it have to run backwards to make the MH go forward?? ED
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Old 07-11-2006, 10:14 AM   #9
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That sounds too expensive to do,the power is very similar on both engines straight out of the box.We installed a 502 with carb.,performer manifold & large fuel pumps in a 1989 fleetwood limited and got 282 Horsepower to the ground.Most 496 coaches get similar results...unless we program them in which case we get 320-360 to the ground.Fuel injection is way more simple & user freindly IMHO
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Old 07-11-2006, 05:24 PM   #10
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<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by eandy:
Thanks,good comeback. Mike, that was 20 yrs ago, but would like to know what problems were. I aware driveshafts would need to be modified or made from scratch. Not unusual. Tried to find info on axle seals at Dana site. No luck but noted huge range of rearends available. Still, if big hp/torq at tires improvement w/o the power loss? Begs the actual answer given the Monaco problems could be dealt with.
Aside from the obviously unaceptable level of detuning of the 8.1 from the factory, I'm happy with the engine tranny combo. There's always room for improvement w/o going stupid w/money. A rear engine configuration necessarily has to be less expensive on driveshaft alone. Still wondering.
BTW my roadsters were all big Healeys. The best w/60 overbore,pistons from England.Tranny rebuilt by a Jag mechanic moonlighting. Never found the top end. Pegged the speedo w/about 20% throttle left. Frontend got too light to persist. All my money went into best mechanical I could afford. Never even had good int. or paint. Yeah LUCAS. Couldn't afford new harness either, did like all others, paperclips and spare reel of wire, cross fingers. But RUN yeah! </div></BLOCKQUOTE>

Couldn't resist the Lucas dig Eandy, I owned a 59 MGA once long ago, but I still remember the SU carb and the Lucas electrical. Your right it did run, and was a blast to drive. Course I was younger then.

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Old 07-11-2006, 06:07 PM   #11
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<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by edgray:
Now here is a question I can't seem to figure out the answer: IF there were a rear facing engine, would it have to run backward to make the MH go forward?? </div></BLOCKQUOTE>A rear facing engine needs only to spin its driveshaft as it normally does. Now imagine if you will a rear facing engine, flip the whole thing over to the front, differential and all and spin the tranny and engine a half turn so it faces up. What changed? You now have a conventionally sitting engine with a very short driveshaft still spinning as it always has through the same set of gears as before.

I think that about does it unless I over looked something.
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Old 07-11-2006, 06:27 PM   #12
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<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I think that about does it unless I over looked something. </div></BLOCKQUOTE>
I'll take your word for it, at least until I can actually see one. Then MAYBE I'll understand, 'cause I sure ain't no engineer! ED
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Old 07-11-2006, 06:51 PM   #13
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Hey there,If memory serves,Didn't FMC try it with the 440-3's. Not sure why but they had beaucoup problems with overheating those pulling engines. I for one couldn't figure out why. any ideas?
Sorry I havn't been on-line much,but this computer has been sick and i've been working to get it back on-line. I hope this is now fixed. Anyway,it's good to be back!!
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Old 07-11-2006, 07:54 PM   #14
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Driver, that makes perfect sense.
The driveshaft doesn't 'lose' horsepower, it merely transfers the power to the diff. And they are cheap to make, a couple of tubes and flanges and a welder. Yeah, you loose a little in the ujoints, but's not appreciable.

The front engine balances the chassis. It's also been developed over the last hundred years and it works. Short diesel pushers are not worth a crap. Doesn't a 32' Journey have a ton of ballast in the front?

If the crate motor is rated for more HP it probably has a more to do with heads, cams, pistons, and any other variety of high performance specs. If it's a carburated motor it's not meant for the hiway (won't pass emissions) so it's a race motor and they have different specs.

Make sense??

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