Home > Herald > Engine Swaps > Herald with Dolomite engine

Anything and everything Herald. Talk about anything from the first 948s to the last 13/60s.

Section : Engine Swaps

Herald with Dolomite engine

Posted By : Steve Cureton, 18-May-2003, 11:37pm

I have just discovered my Herald 13/60 has been fitted with 1500 Dolomite engine. An engine of this size should run well in a Herald but I still find 60 mph is about the comfortable limit before it feels like it's reving hard. Does anyone know if the Dolomite gearbox would swap straight in to the Herald or do you have other ideas on how to improve the better gear ratios? I'm reluctant to change the engine as it's in excellent condition.

Followups :

Herald with Dolomite engine

Posted By : Nigel Gibbins, 19-May-2003, 09:23am

Hi Steve,

Nothing wrong with that engine and I too can't think of any good reason why you should change it. You should aenjoy all hat loverly torque. It's the same engine as the Spitfire 1500, so any 1500 bit should fit straight on - Single rail gearbox, etc.. The only thing to watch out for is the number of splines on the input shaft of the gearbox as this changed for the SR gearbox - but there is a conversion plate available (clutch is bigger - 7.25inch).

So again no worries...

However, if you're running out of revs at 60mph this could be because the diff is still a 4.11. The Spitfire went to 3.63 for this engine and you could consider this instead of the gearbox swap, but it has bigger input and output flanges - Much stronger - so you should check you can up-grade your driveshafts/propshaft flanges too.

Hop this is useful.

NiG
http://www.niginthecar.net
- Herald with Dolomite engine
  
  Posted By : Steve Cureton, 19-May-2003, 05:47pm
  
  Nig, thanks for the advice - your comment about torque is spot on but I didn't realise why until a few days when I discovered it was a 1500! Cheers
Herald with Dolomite engine

Posted By : William Davies, 19-May-2003, 04:26pm

Changing the gearbox will make no difference as the direct drive in top gear will be 1:1. You could fit a 3.89 or 3.63 diff from a Spitfire, but our old Dolomite 1500 had the higher ratio and still sounded quite alarmed at the high end. The 1500 engine though quite torquey has a very long stroke and consequently high piston speed, so it won't rev as well as the 1300.
The best overall option would be to fit an overdrive gearbox - that will drop your revs by approximately 25% (depending on exactly which overdrive you use) when engaged rather than the constant reduction offered by a higher ratio diff.
Cheers,
Bill
- Herald with Dolomite engine
  
  Posted By : Steve Cureton, 19-May-2003, 05:45pm
  
  Bill
  
  You're certainly right about torque, at low revs I'm sure it could pull anything. Looks like I need to save a few quid and get myself an overdrive box. Thanks for the advice. Do you sell these units by any chance and if so any idea how much it would set me back?
  - Herald with Dolomite engine
    
    Posted By : William Davies, 19-May-2003, 08:46pm
    
    Hi Steve,
    Best to drop me a line privately regarding this. Secondhand overdrive boxes don't sit on the shelf with me for very long as I can usually sell them as quickly as they come in!
    Cheers,
    Bill.
- Herald with Dolomite engine
  
  Posted By : Ivan Yates, 14-Jul-2003, 06:18pm
  
  Hi, I dont profess to be an expert but if you have so much torque from the 1500 engine what is the problem with fitting a 3.63 diff. It will be cheaper and simpler than fitting an overdrive unit.
  I am currently fitting 1500 spitfire bits to a 13/60 and will be fitting all the drive chain AND if I can find it an overdrive unit. But in the meantime the original spit bits will do.
  Good luck.
  - Herald with Dolomite engine
    
    Posted By : William Davies, 14-Jul-2003, 06:55pm
    
    The 3.63 diff will drop your overall drive gearing by 11.68%, overdrive units for our cars drop by 20%. If you want a comparable drop in overall revs you will need to install a 3.27 diff - think a 1500 will pull that? Having seen how dreadfully slow a 2 litre Bond is on pickup when fitted with this diff, I can't imagine a 1500 engine is going to make it a ball of fire,
    Cheers,
    Bill.
    - Herald with Dolomite engine
      
      Posted By : Ivan Yates, 14-Jul-2003, 09:05pm
      
      Hi William. So am I doing wrong?. Please tell me before it is too late. I know the Herald is a heavier car but I assumed that if I fitted all the driven parts of the 1500 spit. then I would be playing safe with the intention of having a good touring car rather than something which is quick off the mark.
      I am not sure at the moment whether I can afford to go to the expense of an overdrive, perhaps later. If I try to do too much all at once I may never get the car out of the garage and I really want to drive it. As it is I can see another 2 years work. I would appreciate your advice.
      - Herald with Dolomite engine
        
        Posted By : William Davies, 14-Jul-2003, 09:49pm
        
        Hi Ivan,
        There's nothing wrong with what you're doing, just don't expect the same refinement as with an overdrive equipped car, the reults are very different. We previously ran a very late 1982 registered 1500 Dolomite (with 3.63 diff) as a daily commuter - very noisy by the time you got to 70 and desperately needed an overdrive.
        In an ideal world I would run a Herald with a small crank 1300 engine with MkIII cam and a single large carb (as recommended by Mr Kipping!). I would put this through a 3-rail gearbox (I dislike the feel of the selector on the single rail) with D-type overdrive (adequate for a 1300). I would stick with a late Herald 4.11 diff with the thick output shafts.
        So go for it, but understand what you will end up with. Overdrive is a desirable option on Spitfires with 3.63 diffs too,
        Cheers,
        Bill.
        
        Herald with Dolomite engine
        
        Posted By : Ivan Yates, 15-Jul-2003, 00:25am
        
        Thanks Bill. Your views are much appreciated.
        I will stick with the 1500 but will try my best to incorporate an overdrive unit.
        Many thanks
        Ivan