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Mechanical Tips

We extracted some great tips from our forum


Throttle problem
I had but I lost about 50% movement in my throttle. The cause was the front end grounding, when coming off a steep car park ramp, and bending part of the radiator ducting against cam on the end of the throttle spindle, worth a look. [Panky]


Crank Case pressure & Rusty chasis
4 u green freeks this mite not sound like a good idea but if ure engine is breathing heavy and u dont mind then root the crank case breather into the chassis and oil the inside as u drive ??? no more crank case presure and less rust in your chassis [dozer]


Rootes 1725 engines : the differences
As I'm understanding things, the Commer van has a low compression iron headed single carb version of the Rootes 1725cc engine. Rootes cars sometimes have a high compression version Rootes cars sometimes have twin carbs with different manifold Rootes cars sometimes have an alloy head Finally, there's a rather tasty Holbay tuned version Has anybody fitted any of these versions to their Commer PB and was it straightforward ? I'm guessing the main issue will be space to handle the different manifold and carb arrangements Also, what are the main benefits of the alloy headed engine over the iron version, other than weight ? [Paul Goldsmith]

this is a subject which could be invaluable to everyone,ive asked steve yates to come up with the differences if he can or if hugh reads this he will know all the answers,as far as i know you cannot fit an alloy head to an engine with a cast head without changing the cam the basic engine block was used in rootes cars /vans from 1954 with a 3 bearing crank as a 1390cc .then incresed to 1494cc from 1958.to 1592cc from 1961 and then to 1725cc with a 5 bearing from 1965.it then ran until the early 1980s in the iranian peykan hunter. as far as i know the only reason the engine in the hunter family was at an angle was to enable twin carbs to be fitted hunter engines fit easily into the earlier vogue/superminx/sceptre range as each block has two sets of engine mounting holes drilled into it and you just swop from one engine mounting to the other the tuned holbay ran twin webbers and an 8 1/2 inch clutch same as the commer pb,a company called classic car developments in derbyshire offers a air filter weber conversion kit to enable the holbay engine to sit up straight to be used in sunbeam alpines so should be ok for commer van i thought all sump pans were interchangeable but stand to be corrected we are going to install a holbay engine and transmission into our dodge camper soon so can advise on the pitfalls,we are looking into fitting stromberg 175cd carbs as fitted to the later high performance hunter gls as twin webbers are a pain to keep tuned [Steve Williams]

Steve Williams has given you the basics. The Rootes lump is basically the same from early Minxes to last Hunters except for change to 5 bearings with 1725 and also threaded holes in block for engine mountings for Hunter. You can fit the latter engine into earlier vehicles if you take the timing cover engine mounts off your current engine and swap to new lump. Failure to use right timing cover mounts means bolt hole for mountings won't marry up I've seen a Holbay + O/D gearbox in a van > pretty fast I'm told by Bob Allan Imp Spares guy who had it Low Compression engines meant slogging power low down to haul weight rather than high revs and top end power. Engine changes may mean changing prop shaft and diff ratios to match Engine cover can be a problem as Holbay must have matching Cam and Carbs to work > but work by Cananem (see latest Practical Classics A40 project) means you can go to full engine management and injection on old engines for better drivebility, no choke or alternator slowing engine etc. The A40 gave 20% more power!! on this alone. You have better choice to mount components and with no points etc have low maintenance like modern vehicle and coversion uses scrapyard sourced parts to a significant extent.I know Dave Hampshire the guy who does this as he's an Imp Club member who runs a Chamois Coupe on hos own build system which was his degree course work at York University Hope this has weted your appetite for now [Cali]


Commer stud pattern
stud pattern is 127mm pcd ,same as rover p5, sd1, pre 89 jeep cherokee [commeracer]
also 5 stud ford p100 pick up .. & some new transits [dozer]


Replacing the fuel pump
raise the lift lever arm when the pump is offered up to the engine block/cam. The arm can try to go under the cam, rather than over, it with disasterous consequences if the engine is turned over. Simply slide the string under the lift arm and hold it up in the correct position and slide the pump over the bolts, once in position simply pull the string out and hey presto. I was shown this trick by a retired AA man when we were broken down changing the fuel pump due to snake skin on the side of a French backroad... [Andy Zarse]


Stuck Clutch
First of all make sure the hydaulics are working. You'll need somebody looking underneath whilst you push the pedal. If the pushrod from the slave cylinder is moving the clutch operating lever back and forth then it's not that. Stuck clutches are far more fun. Warm up the engine. Stop it. Put it in first and restart the engine so that your Commer starts to move. With your left foot, depress clutch pedal (it's vital the hydraulics are working, as above) and then with right foot stamp on the other two pedals alternately, going on and off the throttle and brakes. The shunting will either free it all up with a bang, or you run out of road. It's normally just a bit of corrosion on the flywheel sticking stuff together. This method does work, my Commer sits in a field all winter and it happens every year. [Andy Zarse]


Bottom end knock
has the engine got a starter handle dog nut on it? it would be under the fan on the end of the crank. some rootes engines have the nut come loose and it sounds like a bottom end knock [Steve Williams]


Heat/Fuel Vapourisation problems
Re route the fuel line through the rad mounts round front of rad and back to the carb, this will sort out any heat/fuel probs, had the same for ages before I worked it out , no more probs and that was some 10 yrs ago , Fuel cap also a good try [classiccommer]