Exhaust break

Moderators: stan, Chris S, Zoltan

User avatar
bromleyxphil
Gold
Posts: 669
Joined: Tue Jun 23, 2015 9:24 am
Location: Bolton
Contact:

Re: Exhaust break

Postby bromleyxphil » Tue Aug 07, 2018 9:39 am

crinklystarfish wrote:Did we ever find out from BK (or anywhere else) whether fuel is required to be cut when the butterfly is operated?

I still suspect it doesn't but am very curious to know the ins-and-outs of the factory-fitted systems on your average 20-40 yr old truck.

It occured to me that as a result of a rather embarrasing self-inflicted moment that manual non common rail systems might even suffer airlocks if fuel is cut


Steve the upshot seems to be, some do, some don’t .......you get more smoke if you don’t. Not got to mine yet as been too busy selling the house, I will get there soon.

crinklystarfish
Gold
Posts: 1223
Joined: Mon Jan 30, 2012 9:34 am
Contact:

Re: Exhaust break

Postby crinklystarfish » Wed Aug 08, 2018 6:12 am

Ta for the info Phil, it makes the prospect of a retro-fit much less problematic.

User avatar
bromleyxphil
Gold
Posts: 669
Joined: Tue Jun 23, 2015 9:24 am
Location: Bolton
Contact:

Re: Exhaust break

Postby bromleyxphil » Wed Sep 12, 2018 7:54 pm

Well it’s on and working and should be available for viewings at the Overland show. Can’t show you any photos as I can no longer seem to post them on here.

graham bates
Silver
Posts: 16
Joined: Fri Jan 22, 2016 4:27 pm

Re: Exhaust break

Postby graham bates » Sat Nov 17, 2018 2:51 pm

bromleyxphil wrote:Well it’s on and working and should be available for viewings at the Overland show. Can’t show you any photos as I can no longer seem to post them on here.

hi have you upped the valve springs i understand that they need to be changed if a Exhaust break is fitted to our trucks
to fit a exhaust brake you need a minimum 60lbs exhaust valve springs to cope with extra manifold pressure.

User avatar
NeilandPat
Gold
Posts: 1396
Joined: Mon Feb 08, 2010 2:16 pm
Location: South America Going Slow
Contact:

Re: Exhaust break

Postby NeilandPat » Sat Nov 17, 2018 4:00 pm

I am sure Phil will be along soon with the technical details, but I think he had many hours discussing this very point with MAN technical and the end result was that the existing springs were fine.

Im sure he will fill in the blanks soon

Neil

User avatar
bromleyxphil
Gold
Posts: 669
Joined: Tue Jun 23, 2015 9:24 am
Location: Bolton
Contact:

Re: Exhaust break

Postby bromleyxphil » Sat Nov 17, 2018 5:53 pm

graham bates wrote:
bromleyxphil wrote:Well it’s on and working and should be available for viewings at the Overland show. Can’t show you any photos as I can no longer seem to post them on here.

hi have you upped the valve springs i understand that they need to be changed if a Exhaust break is fitted to our trucks
to fit a exhaust brake you need a minimum 60lbs exhaust valve springs to cope with extra manifold pressure.

Hi Graham what truck do you have? Neil is right I have discussed these things at length and the upshot of most of it is that you are on your own. The best answer I could get was from MAN parts who don't have stronger valve springs listed for my engine and the exhaust break was a factory option. I have fitted it, it does work " but not as well as I hoped" some adjustment needed I think. The jury is still out as to turning off the fuel pump or not as it does push out some smoke when I turn it off. What have I learned......there are no experts out there on this subject.

Ivan C
Gold
Posts: 378
Joined: Mon Oct 17, 2016 5:38 am

Re: Exhaust break

Postby Ivan C » Sat Nov 17, 2018 10:10 pm

I was playing around with the one on the "coal lorry" when I was bringing it home and unless the revs were well up it had little more effect than just closing the throttle.
There's a section in the handbook about it and I think this is mentioned.
Ivan C

User avatar
bromleyxphil
Gold
Posts: 669
Joined: Tue Jun 23, 2015 9:24 am
Location: Bolton
Contact:

Re: Exhaust break

Postby bromleyxphil » Sun Nov 18, 2018 7:31 am

Ivan C wrote:I was playing around with the one on the "coal lorry" when I was bringing it home and unless the revs were well up it had little more effect than just closing the throttle.
There's a section in the handbook about it and I think this is mentioned.
Ivan C

Cheers Ivan, what vehicle was it on? Do you think it turned off the fuel? Did it get a puff of black smoke when released?

Ivan C
Gold
Posts: 378
Joined: Mon Oct 17, 2016 5:38 am

Re: Exhaust break

Postby Ivan C » Sun Nov 18, 2018 8:48 am

Hi Phil, it was on the 6cyl donor.
Hard to say about the smoke as a fair bit of the exhaust is missing :o does sound nice though :D
Ivan C

User avatar
NeilandPat
Gold
Posts: 1396
Joined: Mon Feb 08, 2010 2:16 pm
Location: South America Going Slow
Contact:

Re: Exhaust break

Postby NeilandPat » Sun Nov 18, 2018 4:07 pm

Surely it must turn the fuel off.

I cannot see how you coukd block tge exhsust and still have combustion going on.

The pressure would be dangerously high.

Mine definately shuts the fuel off

Neil


Return to “Trucks”

Who is online

Users browsing this forum: No registered users and 1 guest

cron