Date: Mon, 9 Mar 1998 09:28:10 +0100 (MET)
From: Darcy Maddock
Subject: brakes and cam
Hullo to all fellow Impers, I thought it was about time I put in a question. All advice appreciated. I am running an R20 cam. At the moment I am only about 12 degree before TDC with my dissie because of the alternator. I am about to remove the sump to move my oilpump gear around. However given the number of degrees (42) that I need to attain I am sure that more than one tooth movement is required. Any suggestions?
2nd question. I am investigating disc brakes. How much wider will my track be with the Vauxhall/Holden Viva/Torana discs. A dummy run with an Imp stub in a vice suggests that my track will increase by close to 2 inches. If that is so I will be very illegal here in Queensland as my 13" superlights and Pirellis are almost at the edge of my mudguards.
Nice to see Paul Greville around. Must be a treasure house over there Paul. I am saving up for the Imp Nationals this year but when I get back I will have a hard look at what you have available. Bye for now
Darcy Maddock Queensland Australia
Date: Mon, 9 Mar 1998 09:48:53 +0100 (MET)
From: Paul Greville
Subject: Re: brakes and cam
Hi Darcy,
I would recommend that you run the R20 at 108 degrees and get rid of the vac advance unit. You can then cut off the protruding distributor pieces and fill the vacant spaces with silastic or one of the liquid metal pastes that are available. If you have any queries give me a call tonight on 08 90211.139.
Replace it with the old style Lucas (Mini Cooper) fixed distributor baseplate, this modification cures all ills! The Torana disc modification does really improve braking but sadly increases the track, have you considered skinnier tyres?
Regards.
Date: Mon, 9 Mar 1998 16:18:25 -0500 (EST)
From: Nickcleak
Subject: Re: brakes and cam
Hi Darcy,
> I would recommend that you run the R20 at 108 degrees and get rid of the
> vac advance unit. You can then cut off the protruding distributor pieces
> and fill the vacant spaces with silastic or one of the liquid metal
> pastes that are available.
If you are racing it fine , but if you are hoping to use it mainly on the road , i'd strongly recommend the vacuum advance !!
see my letter in the MARCH Impressions ...
Regarding brakes , i have 8 inch ventilatd discs on my Imp , the track is not greatly increased , they are from a 1986 Ford Escort 1600 . i use the calipers too , but the pistons are rather too big which results in all the pedal travel being used to move the pistons up to the disc !
i use a 19mm Master cyl to cure this problem then use the servo on the rear brakes only , This results in a pedal which feels dead and heavy , but you soon find the extra strength when you need to stop quickly , and this it does ..
I always felt that the rear brakes still had a lot more to offer in the imp with all the weight over them , and i am finding this works . so do McClaren apparantly with their third brake pedal and glowing rear discs !!
Nick ...
Date: Mon, 9 Mar 1998 10:21:16 +0100 (MET)
From: ABryson@sperry-sun.com
Subject: Re: brakes and cam
Hi Darcy,
I am still in Indonesia! Unfortunately due to the situation here I did not get to do Rally Tasmania.
Regards the timing, 1 tooth should be enough but think about which way you move them! My engine done by Brian in NZ with R 20 has only 34 deg advance; with a Carter Head and twin 40s. This was set on the Dyno.
The normal distributer gives 28 deg mechanical advance so 12 is not far off to get 42.
My car has Torana front discs & Hubs and 6 X 13 with 185x60x13 just fit under the arches with the inner lip on the arch bent in by a panel beater. An inch each side increase is about right. I am running Mk1 suspension but I understand the Mk2 has a slightly wider track.
I take it you are racing the car as for almost anything else the drums are OK. When I did Appendix J in Perth the drums with VG95 would only last 8-9 laps at Waneroo before they faded. I had to adjust them after every race and practice and renew the front shoes after every meeting which was a pain. The disc pads (DS 11) on my car when racing in Malaysia never faded even in 25 lap races at 35C and lasted years!
Regards,
Andy
Date: Mon, 9 Mar 1998 15:15:24 -0500 (EST)
From: Gary Henderson
Subject: Re: brakes and cam
Hi folks
Can you find some wheels with more backset? This should be possible, because most FWD vehicles need it to accommodate all that extra driveaxle stuff...
Cheers
GaryH
Date: Mon, 9 Mar 1998 16:22:50 -0500 (EST)
From: Gary Henderson
Subject: Re: brakes and cam
Hi Darcy, Paul
The 43D distributor has no vac advance hardware, and has bigger clearances and creepage distances in the cap than 25D, the better to withstand high spark voltage of high-compression engines. It was used on Avengers c.1974, among others. One drawback: It's a bit prone to going high-resistance in a couple of places around the QuickFit contact set. (But Joe Lucas made a reluctor conversion set for it.)
Cheers
Garyh
Date: Wed, 11 Mar 1998 09:13:33 +0100 (MET)
From: Darcy Maddock
Subject: Re: brakes and cam
Thank you Paul, I will take the vacuum advance unit out and see if I can get the dissie to go around far enough without surgery. If successful I will tape it intitially and see what the fuel consumption is like otherwise it is off with the sump and trial and error. The car is an everyday unit with an occasional foray on the track with some gymkhana work and possible hillclimbs.
I am sick of adjusting the brakes and also the good linings are no longer available from the local suppliers here in Brisbane. Thanks again for the tip. Darcy Maddock
Date: Wed, 11 Mar 1998 03:17:58 -0500 (EST)
From: Darcy Maddock
Subject: Re: brakes and cam
Thanks Andy, I will intially try Pauls suggestion of removing the vacuum unit and if I get the results I want I will take the sump off and move it one tooth. As far as the brakes are concerned do you know if the difference is in the wishbones or the axle stubs. Perhaps it may have been the camber that reduced the track. I would prefer to keep my superlites but I feel happier with discs because their are times that I stretch my friendship with my drums. Thanks again Darcy Maddock
Date: Wed, 11 Mar 1998 10:37:49 +0100 (MET)
From: Gary and Carol Henderson
Subject: RE: brakes and cam
Hi Darcy
Distributors for 1500 cc iron-head version of Hunter had about 40 deg centrifugal advance. ( I have the charts for Hunter dissies.)
Re track etc: No time to hunt for the info just now, but I think neither - the difference I think is in the pivot brackets. The track-rods are also incompatible.
I can check at the weekend (in print or by comparison of my best Mk 1 versus a whole front-end I have stashed.) - give me a nudge.
Cheers
GaryH
Date: Wed, 11 Mar 1998 10:34:14 +0100 (MET)
From: Gary and Carol Henderson
Subject: RE: brakes and cam
Hi Darcy
I am surprised at any limitation on available linings for the front drums - they are same shoes as Mk 1 Escort. (Ususally enough for an Imp, but pathetic on the bigger car.)
Cheers
Garyh