jake brake installed today, on 818

[atvcat33]

ok here goes the story, the truck has a straight 5" right off the manifold and barks like no other truck, so figured jakes would be insane, after digging around found some the models to look for are a 25A, 25B and a 425A, all are for the 855 block of this time period, n14 are different. also not cheap, 600.00 for used and up to 3000.00 for new, the only one availible now new is the 425A. the others are not in production, and are pretty much maintence free. the truck is INSANE LOUD, i have a stage 3 jacobs switch. the truck had a few obsticles to deal with,

when we pulled the valve covers off we noticed the rockers on the center head were differnt than those on the other 2, look at the pic. that wider valve needs to be shaved down to look like the others

on hand was a special template to use to make sure not too much was removed, the rockers were all cummins, the rockers in the center would have been with the motor since new as most now are all the skiny type. more pictures comin in a few mins....

 

[atvcat33]

now after the head is off we needed to remove rocker feet on the exhaust valves only, these were replaced with the larger ones in the jake kit. the heads are only removed to repalce thse valve rocker feet, now after installing new gaskets we were ready for head to put back on. old head bolts are not needed we now have longer ones to consume the added height of the jakes as well we need to reset and adjust valves and injectors, which meant bumping engine over with a bar and lining up the timing marks, and then ready for jake heads more pics.......

 

[atvcat33]

and then after jake head are installed and tight we then needed to run wires and switches.
the clucth switch and tharottle switch each head all ran off the swicthes in the cab. on stage 1 its the first head, and on stage 2 its just the rear 2 heads, and on 3 its all 3.

the front jakehead need to be ground down to accept the stock radiator support, the oil sending unit was moved to the knock out above and the blow by tube extended. the radiator cap hits the hood and i have a finger to fit between the first valve cover and the hood. and my hood is dented all over and isnt straight, so people that cut holes in there hood to alow clearance must be on something cause i have no issues except for the radiator cap which i can just move the bracket around and i had to shorten the blowby tube. and the solenoids are 12 volt so i ran it to one battery and put a 25Amp fuse on and bark away i go, i had these put on by a truck shop who specializes in older equipment and has done hundreds of jake installs with 4 guys and cummins tools we pounded it out in a 11 hours and i was able to drive it back home for 4 hours barking away, total cost $1650.00 but WELL WORTH EVERY PENNY, SOUNDS LIKE NO OTHER JAKE

 

[Castle Bravo]

Very cool. You should get some video so we can hear it.

 

[srodocker]

I second a video!

 

[atvcat33]

once i figure how to upload video.... ill post it here and on you tube, trying to get it the right file type isnt easy

 

[Alredneck]

Sweet on my ride home today from picking up the last of the CUCVs I was wondering what Jakes would fit on the 250 cummins as my International is getting to be to slow so need to get the M814 Tractor conversion up to speed. Been thinking about all the 400 to 250 commons and not commons trying to get everything figured out.

 

[wreckerman893]

Captain.....if I deep six the M-816 I will have a 290 for sale (never got a chance to install it)....it came out of a log truck and was prob run hard and put up wet but it has a good turbo on it and would prob be easier to install Jakes on. It ran good when we pulled it but smoked a little when first cranked.
Give me a call.....I'll sell it out right or trade it to ya for something to feed my addiction.

 

[Andydieselpower]

Awesome!!!! I've been wanting to add jakes to one of our M818's for a while now. We plan on straight piping one of the trucks soon. I can't wait to see the video. There is a video on youtube of an old cabover with a NHC 250 with jakes. I bet that truck sounds great!!

Thanks for the pics and info!

 

[oldshep]

Pretty cool. Jakes are music.

 

[ryanaubra]

Looks good

 

[HanksDeuce]

6 years and still no video.