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Derrington Four branch copy
Posted: Wed Apr 08, 2009 7:43 am
by Keith
Hello,
As you know I am going to have some copies made of my Derrington 4 branch. (4 into 2 into 1) that fits the sidevalve with standard or high compression head such as Derrington Silvertop etc.
Just need to test the market to see how many people are interested, NO commitment to buy, just so I know the numbers and can get a price for the quantity.
Please PM me if you have an interested, once I have the numbers I will get a price.
I don't intend to make any profit from this, just to cover the costs..
If the project progresses well I may have a batch done by the MM Rally in June....
thanks Keith
Posted: Fri Apr 10, 2009 2:49 am
by tortron
any chance of a photo?
Posted: Fri Apr 10, 2009 7:13 am
by Keith
copies are not made yet....
Posted: Fri Apr 10, 2009 10:46 am
by RobThomas
I'd guess that I would buy 2 if they came out at a price that didn't break the bank. The option to buy enough pre-fab bits to add a single carb or twin would be an advantage (as we discussed). It would be handy for me to have a flat area below the 4 - 1 collector so that I could screw in a 14mm plug for a Lambda reader. Will it be sized to fit into a standard 1098 exhaust backpipe or just the early bore?
Posted: Fri Apr 10, 2009 11:59 am
by tortron
Keith wrote:copies are not made yet....
of the original?
Posted: Fri Apr 10, 2009 2:20 pm
by Keith
Rob, Thanks, I've sent you a PM, had you name on the list already. regards Keith
re the picture of the original, I don't have it, its with my friend who will make up the copies....I'll let you have an picture of the copy once complete..
Derrington Four branch copy
Posted: Sat Apr 11, 2009 9:24 am
by ian.mcdougall
Hi Keith
Is there any advantage to fitting the four branch on a standard engine as the exhaust manifold section of my combined manifold is a bit rough and is hard to get a seal to the head i would have to separate the exhaust from the inlet to use it, or does any one have a good 2nd hand one spare
regards Ian
Posted: Sat Apr 11, 2009 5:22 pm
by mike.perry
I recon a decent 4 branch will be a considerable improvement over the standard unit. The only problem will be sorting out a single or twin carb inlet manifold. I don't know whether the inlet section can be chopped out of the standard manifold. There is always the Monaro kit for twin carbs.
I would assume that the 4 branch bolts onto the front of the silencer as a direct replacement for the front pipe. The advantage also is that it will do away with that awkward manifold joint. In case you didn't receive my PM, I am interested. What cost are you aiming for?
Posted: Sat Apr 11, 2009 7:15 pm
by Keith
Ian, As Mike says, there will be a benefit, just need to work out how the inlet will connect. I'm going to have a sample made, so I'll see what I can do with an original inlet.
regards Keith
Posted: Sat Apr 11, 2009 8:50 pm
by alanworland
I guess the Derrington setup would come out of the block at a much more gracefull angle to aid gas flow, so I would think a problem could be encountered with exhaust ports 2 and 3?
If poss would you be able to take a photo from the front so that an idea of how much room it takes? I would like to be able to clear my existing twin setup
Posted: Sun Apr 12, 2009 8:09 am
by Keith
There is an amount of downward slope of the pipes.....I'm sure all will be revealed once I have the sample set up in a car.... I will try various setups....

Posted: Thu Sep 17, 2009 3:26 pm
by RobThomas
Any news, Keith?
Posted: Fri Sep 18, 2009 4:40 pm
by Keith
Rob, Your timing is just right. I couldn't get the guy who made my one off for my car (Alta/Shorrock combination) to make the Derrington copy...too much on. I have since only just found someone who will make a copy for me. I will be taking it around to him the week after next. I'll keep you posted.
regards Keith
Posted: Fri Sep 18, 2009 9:04 pm
by mike.perry
Looking forward to it. It would be great to have the twin carb setup when the engine is rebuilt.
Posted: Fri Sep 18, 2009 9:16 pm
by alanworland
Looking forward to releasing all that extra horsepower!
Posted: Fri Sep 18, 2009 11:32 pm
by mike.perry
Looking forward to releasing all that extra horsepower!
Yes, both of them!!!!!!!
Re: Derrington Four branch copy
Posted: Sat Jan 16, 2010 3:50 pm
by Keith
An update, I had some time over the Christmas, so contacted the chap re the four branch. He has completed all the tubes etc. I now need to take an MM along to have a trial fit to ensure it clears the body etc before he completes the final fabrication, etc...I'll take a car up to him in the next couple of weeks...Keith
Re: Derrington Four branch copy
Posted: Sat Jan 16, 2010 9:15 pm
by mike.perry
My exhaust pipe is in three sections, down pipe, silencer, tail pipe, which I assume is normal. Can the new pipe be made the same length as the down pipe so that it flanged over the front pipe on the silencer. You would have to allow for the extra height of the Alta head so that the silencer would just clear the floor with the Alta head and hang a bit lower with the side valve head. It would up the costs if a separate exhaust had to be made for each application.
Re: Derrington Four branch copy
Posted: Sun Jan 17, 2010 4:29 pm
by alanworland
Surely Mike there is quite a bit of difference in height between the s/v and Alta pipe positions? Do you think it (the body opening/floor/ground clearance) can accomodate both types?
Re: Derrington Four branch copy
Posted: Sun Jan 17, 2010 5:31 pm
by jarvo
Hi, I would definitely be interested in one. Chris Jarvis (Jarvo) e-mail:
morrismm50@msn.com