CharlesElliott Posted March 9, 2016 Share Posted March 9, 2016 Continuing with my never ending car rebuild, the alternator is hard against the chassis rail. The belt is 738mm which is a little longer than the 735mm I believe the OEM is, but 1.5mm is only going to give me about 1mm of clearance. Part of the problem is that manufacturers seem to give equivalent part numbers to 5PK735 that vary in length by a few mm which might be OK in an MGF but not in a Caterham. Two questions. Is there any other way to create more alternator clearance? I've loosened the engine brackets to mount bolts, I could potentially undo the rubbers as well but I can't see that giving me more than a mm if anything. Does anyone have a certain source of belts that are less than 735mm? I have an Apollo, so I cannot go too much shorter either. Something like 730-732mm would seem better, unless I can create alternator clearance in another way. Charles Link to comment Share on other sites More sharing options...
SM25T Posted March 9, 2016 Share Posted March 9, 2016 Could you get longer Apollo hoses made up and reroute them so they don't pass through the belt ... then you could go much shorter with the belt. On my SV have the sandwich plate with the outlets horizontal and route the hoses under the alternator. Are you sure the engine mounts are ok .... and gearbox mount is centred ? Link to comment Share on other sites More sharing options...
revilla Posted March 9, 2016 Share Posted March 9, 2016 If you Google 5PK730, looks like there's a Dayco belt quite widely available, apparently for a Peugeot 605. That should be 5mm shorter. Link to comment Share on other sites More sharing options...
SM25T Posted March 9, 2016 Share Posted March 9, 2016 Of this works for you .... just take your existing hoses to a hose distributor like Parker, Pirtek, or any hydraulic hose place and they will make them up for you. Tell them they are for engine oil at up to 6 bar and 120C. Link to comment Share on other sites More sharing options...
SM25T Posted March 9, 2016 Share Posted March 9, 2016 Remember a belt 5mm shorter only changes the centre to centre distance by 2.5mm Link to comment Share on other sites More sharing options...
CharlesElliott Posted March 9, 2016 Author Share Posted March 9, 2016 Thanks both. I'm not sure if there is enough room to re-route the hoses (and that would still need a shorter belt) and from a regs perspective it might be difficult to get aftermarket hoses made. Alternator belts are free. That 730 might be an option, it would be 8mm shorter than the current belt and 5mm shorter than OEM. Should give 4mm more clearance.Revilla - didn't you post that you bought a belt from Rimmer Bros and it turned out to be a 730? Link to comment Share on other sites More sharing options...
revilla Posted March 9, 2016 Share Posted March 9, 2016 Actually yes, you are right! You've got a better memory than I have, even for my own posts Just looked back at my emails for the order confirmation. What I ordered was this http://www.rimmerbros.co.uk/Item--i-PQS100840P, so a pattern part for PQS100840.What I got was this:I guess that part number is generic for "a pattern part" so I wouldn't like to guarantee you would get the same, but you probably would.If it's any help, with the belt nicely tensioned the measurement between the outermost edges of the pulleys is 128.5mm, measured as shown below, and that is with an alternator pulley that measures 52mm diameter as shown in the last picture (the camera angles aren't quite straight so the measurements look slightly out but viewed straight on they are pretty close to the ones given above). Link to comment Share on other sites More sharing options...
CharlesElliott Posted March 9, 2016 Author Share Posted March 9, 2016 I've started by ordering an OEM and pattern belt from Rimmer. Will see what turns up. Link to comment Share on other sites More sharing options...
CharlesElliott Posted March 9, 2016 Author Share Posted March 9, 2016 And a 730 belt from Amazon. Link to comment Share on other sites More sharing options...
revilla Posted March 9, 2016 Share Posted March 9, 2016 "Belt and Braces?" Link to comment Share on other sites More sharing options...
CharlesElliott Posted March 9, 2016 Author Share Posted March 9, 2016 I'm already missing our pre-season track day this weekend because the car's not ready and with a rebuilt car, it's pretty important to test it out. At this rate I'll miss the first race at Silverstone in two week's time as well.... Link to comment Share on other sites More sharing options...
CharlesElliott Posted March 10, 2016 Author Share Posted March 10, 2016 Think I've fixed it. I ordered two belts from Rimmer, one genuine, one pattern. The pattern belt was marked as 735 and went on first. I also undid all of the engine mounts and pushed the engine over although I don't really think it moved. Tensioned the belt up and now I have a few mm of clearance. Link to comment Share on other sites More sharing options...
ECR Posted March 10, 2016 Share Posted March 10, 2016 I'd stick a bit of masking tape on that chassis member. If you get engine rock it will give you a witness mark.Not trying to alarm you and I think it will be ok as it's low in the engine bay but it would be a shame to have an alternator failure due to it touching the chassis when driven in anger..... Link to comment Share on other sites More sharing options...
CharlesElliott Posted March 10, 2016 Author Share Posted March 10, 2016 Thanks Roger, had already done that! Link to comment Share on other sites More sharing options...
revilla Posted March 10, 2016 Share Posted March 10, 2016 Good news. Link to comment Share on other sites More sharing options...
Fyldeflier Posted June 4, 2016 Share Posted June 4, 2016 Thought I would resurrect this thread.my car a 1400 ss. Has the old style large magnetic marelli alternator and with the belt tightened to give about 4mm either way at the longest run the alternator is only about 2 MM. from the chassis tube.the belt is a 40750 and having looked on google etc I can't find one that's a bit shorter to help give a bit more clearance. Do these things stretch with age? Maybe a new one might helpI am thinking of fitting on of those smart looking tensioners with a turnbuckle type thing at each end as I think that the original Rover tensioner is a bit tatty.any ideas ?thanksJohn. Link to comment Share on other sites More sharing options...
Superwhite R283 Posted June 4, 2016 Share Posted June 4, 2016 I’ve got a k series in a metric s3 with a powerspeed exhaust and with a standard 5pk735 belt the alternator electric connection touches the exhaust (ie melted it a little), so tried numerous shorter belts and found the shortest that will go on is a 5pk718 (with a standard alternator) giving me a little clearance for the connector and exhaust. Got the belts from a local motor-factor Link to comment Share on other sites More sharing options...
Mankee Posted June 4, 2016 Share Posted June 4, 2016 John, when I used to run the 1.4SS alternator setup, I used a shorter belt from Halfords. The equivalent I can find nowadays is a 4PK737, same number of peaks as yours but 12 to 14mm shorter. Easily available and worth a try. Link to comment Share on other sites More sharing options...
Fyldeflier Posted June 4, 2016 Share Posted June 4, 2016 Thanks Mankee. That sounds like a plan! I will give it a try . Link to comment Share on other sites More sharing options...
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