| Author |
Message |
Steve Neely (66.225.4.5)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 13, 2004 - 8:01 pm: | |
I have a 8V-71T that had problems. After having it pulled apart I found size 80 injectors. Pedco in California built it. The motor has a cracked head and bad rings from over heating. What size injector would be best for long life and OK HP? I don't think it has an after cooler. |
RJ Long (Rjlong) (67.181.236.27)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 13, 2004 - 9:19 pm: | |
The simple answer to your question:
It depends. . .
What coach is this motor in? A lightweight GMC or heavier MCI, Prevost or Eagle?
Basically, since you've got the engine torn down, here are your options:
~ Standard timing w/ N60 injectors = 275 hp
~ Advanced ("A") timing w/ N65 injectors = 304 hp (often called 318 by the truckers)
~ Standard timing, N75 injectors plus adding a turbocharger = 350 hp
~ Standard timing, 7C75 injectors, adding a turbocharger plus an after cooler (if your block will support it) = 370 hp
Best fuel mileage and longevity will be w/ the N60s, which is what most bus companies used.
How fast you want to go also translates into how often you want to stop for fuel. . .
While you've got it apart, get a Jake brake installed, too. Well worth the extra bucks.
HTH,
RJ
PD4106-2784
Fresno CA |
Geoff (Geoff) (66.238.120.69)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 13, 2004 - 9:46 pm: | |
Go with N75's. BTW, I was at a MAK Bus Convention a few years back, and one of the speakers at a re-power seminar was Virgil Cooley from PEDCO. I specifically remember him saying that 8V71T's were notorious for overheating the heads, and he recomended going with the aftercooled (8V71TA) engine. Humm...
--Geoff
'82 RTS CA |
Dwight (67.213.8.162)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 13, 2004 - 11:50 pm: | |
I do not know what kind of H.P. you need but I am running a regular 8v71 with 18.1 compression pistons an added a turbo with out the aftercooler and N70 injectors, have 5000 miles and no overheating problems yet, about 330 H.P. |
FAST FRED (4.245.188.247)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 14, 2004 - 5:14 am: | |
"How fast you want to go also translates into how often you want to stop for fuel. . .'
To expand on RJ's correct info, most coaches go as fast as you wish ,on the Level.
The ONLY advantage to hot rodding is HILLCLIMBING.
Sure there will be a slight benifit in all full throttle accelerations ,
but the hills are where you will notice any power increase.
Unfortunatly some left coast hills are LONG , so the hot rod coach will always suffer potental problems with overheating.
Overheating is the easiest way to KILL any DD.
$10-$14K rebuilds for 10 min, "Saved"?
Caviat Emptor,
FAST FRED |
Marc Bourget (209.142.38.81)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 14, 2004 - 9:17 am: | |
More like:
Caveat Stompor (too much foot in the throttle)
Caveat Non-shiftor (Too high a gear)
Even a hot rodded coach will survive if a prudent driver will take away some foot and a gear,
But then the speed parts are simply a waste of money to match the extra fuel going out the tail pipe!
Onward and Upward
Marc Bourget |
John Rigby (65.112.227.94)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 14, 2004 - 10:27 am: | |
I agree with FF. As those left coast hills have got me twice. Not to the tune of $10k but two cylinder head gaskets on my 671 in the last 18 years.Hopefully my new rad core has put an end to that.
John |
John Rigby (Unregistered Guest)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 17, 2004 - 8:28 am: | |
Just checking to see were and how this would appear. |