Bigjohn4300 Posted September 12, 2022 Share Posted September 12, 2022 Im curious, how much power could a 78 era maxidyne motor make in a low hours/non work application? Engine in good shape, truck is basically a toy, maybe 1000 miles a year. 400 hp? What is its limiting factors? Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/ Share on other sites More sharing options...
fjh Posted September 13, 2022 Share Posted September 13, 2022 15 hours ago, Bigjohn4300 said: Im curious, how much power could a 78 era maxidyne motor make in a low hours/non work application? Engine in good shape, truck is basically a toy, maybe 1000 miles a year. 400 hp? What is its limiting factors? THE LIMITING FACKTOR ON THESE IS THE ENGINE BLOCK! 300 MAYBE ! Just my opinion not a fact 2 Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-509254 Share on other sites More sharing options...
Dirtymilkman Posted September 14, 2022 Share Posted September 14, 2022 I was told by an old mack guru in my area that 425 at the wheels was max. But I wouldn't have my foot in it for to long. Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-509295 Share on other sites More sharing options...
mrsmackpaul Posted September 14, 2022 Share Posted September 14, 2022 I reckon 425 would really stretching it It's only a little motor but I really dont know Yes the block probably is the weak point, they used to crack out here with just a standard tune, I guess it would depend on how long it is planned to be driven hard A hour or so maybe okay Paul 2 Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-509297 Share on other sites More sharing options...
fjh Posted September 14, 2022 Share Posted September 14, 2022 (edited) 5 hours ago, mrsmackpaul said: I reckon 425 would really stretching it It's only a little motor but I really dont know Yes the block probably is the weak point, they used to crack out here with just a standard tune, I guess it would depend on how long it is planned to be driven hard A hour or so maybe okay Paul Exactly! You can triple the HP on a E9 But how log will it last is the issue! the E6 as Paul stated there even at 285 maxi dyne was susceptible to this they did make a 315 thermal dyne as stated before in another thread there was a reason the E7 came along! sure you can turn it up but DO YOU Really want to?? If you want to keep your toy alive just leave it! in my mind A half turn on the screw is all I would consider myself ! You don't want to be getting your foot into it for any serious work thou ! Edited September 14, 2022 by fjh 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-509309 Share on other sites More sharing options...
Popular Post theakerstwo Posted September 14, 2022 Popular Post Share Posted September 14, 2022 With big HP the main brg bore will get out of line and some times will crack the block at the lower end.I as well as many others have started to replace main brgs and found new brgs will not go in because line bore is off due to the fuel was set up.This is the two valve engine and when this happens you pull block and send to machine shop.The later E6 will do same thing. 2 1 Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-509367 Share on other sites More sharing options...
Bigjohn4300 Posted September 16, 2022 Author Share Posted September 16, 2022 Ok, need to live with 300 if i get it- thats what i needed to know....thanks!! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-509485 Share on other sites More sharing options...
Popular Post Joey Mack Posted September 16, 2022 Popular Post Share Posted September 16, 2022 im no guru on E-6's, but when I was a New driver 22+ years ago, I came off the road and went to construction.. Most of what I drove was R's and DM's (tri-axle's) all E-6 and X107 twin sticks (Awesome tranny) and a (9 spd, R model tractor) and my favorite R model tractor had a 12 spd.. 1070B.. Those trucks were slow, but hauled the same loads as the E-7's and the NEW E-Tech's.. and they took the same beating in and out of the pits, and going down the country roads. To me they are tried and true. The driver just needs to understand the machine for what it is, and use it as it should be used.. I know a lot of guys want to be the fastest with the most 'Pony's'.... I cant say anymore, because of my limited experience. I just know that the E-6 will get the job done... In my opinion... Jojo 4 2 Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-509486 Share on other sites More sharing options...
Freightrain Posted September 16, 2022 Share Posted September 16, 2022 Older friend used to run a tandem R with 237/5 spd local asphalt. Never fast, but got the load there reliably. Diabetes finally took him out of the seat for good. Being a drag racer, I'd love to have "more" then my 237. But it gets the job done reliably. 1 Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-509596 Share on other sites More sharing options...
tjc transport Posted September 16, 2022 Share Posted September 16, 2022 I had a 237 twin stick 5 speed in my 79 dm. The turbo went and all the local shop had was a 285 hp turbo. Put in the larger 285 injectors with the bigger turbo, and turned up the pump to match. That truck would keep up with the 400 hp 8ll trans triaxles, only falling back on long upgrades. 1 Quote when you are up to your armpits in alligators, it is hard to remember you only came in to drain the swamp.. Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-509604 Share on other sites More sharing options...
Freightrain Posted September 16, 2022 Share Posted September 16, 2022 See.... I'd love to spice up my 237....just a bit....Lol. Find a tip turbine..... Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-509631 Share on other sites More sharing options...
brettj3876 Posted September 24, 2022 Share Posted September 24, 2022 https://youtu.be/1a7jNgVgClA Apparently a 1430 E-6 with 3 turbos and some custom pump work. Just a show truck but she hasn't blown up yet. Blew a boot on Dyno 1 Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-510231 Share on other sites More sharing options...
mrsmackpaul Posted September 24, 2022 Share Posted September 24, 2022 Yep it gets motivated all right, but for how long ? Laugh at old mate holding the camera pulled away when he backed off at the end lol Paul 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-510241 Share on other sites More sharing options...
Bigjohn4300 Posted September 28, 2022 Author Share Posted September 28, 2022 Ok, so basically 300/315 safe. Is a 78 a E-6? Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-510472 Share on other sites More sharing options...
Joey Mack Posted September 28, 2022 Share Posted September 28, 2022 yes.... yours is a 2 valve, and I think in '86 the 4 valve came out.. '90 was the first E-7... Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-510473 Share on other sites More sharing options...
Bigjohn4300 Posted September 28, 2022 Author Share Posted September 28, 2022 Got it, thanks Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-510474 Share on other sites More sharing options...
Joey Mack Posted September 28, 2022 Share Posted September 28, 2022 I don't see where you posted the model. I assume 'R' possibly DM.. whatcha got .. pics are always a joy 😊... What tranny? Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-510475 Share on other sites More sharing options...
Quickfarms Posted September 28, 2022 Share Posted September 28, 2022 50 minutes ago, Joey Mack said: yes.... yours is a 2 valve, and I think in '86 the 4 valve came out.. '90 was the first E-7... my 1985 came with a 4 valve Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-510478 Share on other sites More sharing options...
Joey Mack Posted September 28, 2022 Share Posted September 28, 2022 Yeah, I couldn't remember for some reason.. glad you cleared it up.. Quote Link to comment https://www.bigmacktrucks.com/topic/70429-79-maxidyne-max-power/#findComment-510479 Share on other sites More sharing options...
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