MJH2454 Posted July 29 Report Share Posted July 29 Hi, I'm looking for opinions. Currently I have a later MKIV spitfire and engine, ie large crank and mild cam. I find this engine in a bit of no mans land, not having the revving capability of the MK3 and early MKIV's nor the torque of the later 1500. Personally I never like revving the engine beyond 3000rpm so a revvy engine is not for me, however I find my existing engine a bit lacking in both pace and pull, ie torque. I'm considering the merits of switching the engine out for a 1500 engine, what do people think? Secondly can I use my existing head on a 1500 engine? I'm considering having the head redone and converted to unleaded and refurbishing the original rocker shaft and rockers, its all a bit clattery! My current engine is about 20,000 miles or more short of needing a full rebuild, ie reasonable oil pressure and 140psi compression readings across the board Or should I just bite the bullitt and obtain a 1500 engine and have the whole thing rebuilt ? Disregard costs in your opinions Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 29 Report Share Posted July 29 (edited) 13 minutes ago, MJH2454 said: My current engine is about 20,000 miles or more short of needing a full rebuild, ie reasonable oil pressure and 140psi compression readings across the board 20k more and you're gonna rebuild it? Why? You can guess I'm in the "If it's not broke, don't fix it camp" There is no point going unleaded until your engine has a problem, don't bother, it may never happen. However if you want a 1500 engine, go for it! Doug Edited July 29 by dougbgt6 Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 30 Report Share Posted July 30 are you sure the seemingly lack of power is just not down to carbs and dizzy etc ??? whats your engine number that will tell if you have the large valve head ?? Pete Link to comment Share on other sites More sharing options...
Mjit Posted July 30 Report Share Posted July 30 If you want more torque and low revs then just buy a 1500 engine and rebuild that before you fit it. Link to comment Share on other sites More sharing options...
MJH2454 Posted July 30 Author Report Share Posted July 30 1 hour ago, Pete Lewis said: are you sure the seemingly lack of power is just not down to carbs and dizzy etc ??? whats your engine number that will tell if you have the large valve head ?? Pete I do believe that it is the large valve head FH62844HE. The carbs and dizzy are fine and the car performs faultlessly, I just feel that my style of driving leans more toward the low revs and torque of the 1500 engine Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 30 Report Share Posted July 30 good the 1500 does generate a lot of torque but is a less friendly motor than the 1300 and life expectancy is far more limited . Pete 1 Link to comment Share on other sites More sharing options...
johny Posted July 30 Report Share Posted July 30 34 minutes ago, MJH2454 said: I do believe that it is the large valve head FH62844HE. The carbs and dizzy are fine and the car performs faultlessly, I just feel that my style of driving leans more toward the low revs and torque of the 1500 engine Perhaps you need to get to a meet somewhere and blag a ride in a 1500 to see how it feels? Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 30 Report Share Posted July 30 its a lot easier to give it an Italian Tune up and drive like you stole it protects the wallet and it will get the biggest smile back Pete Link to comment Share on other sites More sharing options...
MJH2454 Posted July 30 Author Report Share Posted July 30 44 minutes ago, Pete Lewis said: its a lot easier to give it an Italian Tune up and drive like you stole it protects the wallet and it will get the biggest smile back Pete Oh I get plenty of smiles per mile, this car gets used almost every week all year round, done two trips to France, LeMans and Laon, over 12000 miles in my 4 years of ownership and never let me down, having said that I hope I have not tempted fate. What do you mean by a less friendly engine? Link to comment Share on other sites More sharing options...
Steve P Posted July 30 Report Share Posted July 30 I think Pete means they have reputation for running the main bearings prematurely and are not as revvy as the 1300's. I put a rebuilt 1500 in my Herald 13/60 as I wanted a bit more grunt to go with the o/d gearbox and 3:63 diff. Like you I don't rev it much beyond 4k, you don't need to unless your on a track day. Mine has a higher lift cam, uprated oil pump and roller rockers with head and manifold work with a 4 into 1 exhaust manifold. It managed 92 Bhp on a rolling road and is really nice to drive. Steve 1 Link to comment Share on other sites More sharing options...
DanMi Posted July 30 Report Share Posted July 30 (edited) to get the best from a 1500, which is not a rev happy unit you would really want to put a 3.63 diff in. I ran a mk2 with a 4.11 diff with a 1500 and that was only viable as I had overdrive, the mk4 3.89 will be better but still a bit low without overdrive. To fit a 1500 you would also need to consider clutch/gearbox. Easiest is to use the mk4 flywheel and clutch with your existing box Edited July 30 by DanMi 1 Link to comment Share on other sites More sharing options...
SpitfireGeorge Posted July 30 Report Share Posted July 30 What about a TR7 2 litre engine and box, would that go in without too much hassle? Link to comment Share on other sites More sharing options...
DanMi Posted July 30 Report Share Posted July 30 26 minutes ago, SpitfireGeorge said: What about a TR7 2 litre engine and box, would that go in without too much hassle? It has been done but is not a simple straight swop, probably little easier than putting an mx5 lump in Link to comment Share on other sites More sharing options...
johny Posted July 30 Report Share Posted July 30 Probably better off with a Triumph 6 and I would fancy a 1600 - cheaper and easier to find? and possibly a better match for existing components than a 2L.... Link to comment Share on other sites More sharing options...
DanMi Posted July 30 Report Share Posted July 30 1 hour ago, johny said: Probably better off with a Triumph 6 and I would fancy a 1600 - cheaper and easier to find? and possibly a better match for existing components than a 2L.... but isn't the 1600 and even the 2.0 a rev happy unit wheras the post author wants torque rather the high rev power maybe a 2.5. 1500 is a probably a better match for their wonts. Link to comment Share on other sites More sharing options...
Nigel Clark Posted July 30 Report Share Posted July 30 Had you considered staying with your present engine and giving it a few tweaks? The Mk4 1300 isn't the most powerful Spitfire engine but it will respond well to a slightly hotter camshaft e.g. from the Mk3, plus a stage 2 head and suitable needles in the carbs. Nigel Link to comment Share on other sites More sharing options...
johny Posted July 30 Report Share Posted July 30 6 minutes ago, DanMi said: but isn't the 1600 and even the 2.0 a rev happy unit wheras the post author wants torque rather the high rev power maybe a 2.5. 1500 is a probably a better match for their wonts. Dont know about the 1600 but I drive my 2L Vitesse in 4th most of the time (suits my driving needs and protects my gearbox). It pulls cleanly from 1100 rpm and theres definitely no need to rev it especially if it was in a Spitfire😲 Link to comment Share on other sites More sharing options...
Steve P Posted July 30 Report Share Posted July 30 I think a 1600 or 2l in a spit completely changes the character of the car with the boat anchor up front. As I said I have a tuned 2.5 Vitesse and a tuned 13/60 1500 Herald with a single rail o/d and 3:63 diff, If I had to pick a nicer drive it`s the Herald as the Vitesse is a bit of a wrestling match, although I love the 172 bhp grunt of the Vitesse. I was thinking earlier, my Herald had an FH 1300 engine in it before the 1500, from memory it had twin SU`s and a decent manifold and Vitesse exhaust, I did the 2014 Round Britain in it and it got ragged for 48 hours non stop and it was brilliant. Well worth thinking about pepping up the original engine. Steve Link to comment Share on other sites More sharing options...
andybeau Posted July 30 Report Share Posted July 30 Rover 3.5 V8 just to put the cat amongst the pigeons 1 Link to comment Share on other sites More sharing options...
Nigel Clark Posted July 30 Report Share Posted July 30 1 hour ago, andybeau said: Rover 3.5 V8 just to put the cat amongst the pigeons Yes, would be fun but getting everything connected and working properly involves some serious work! Nigel Link to comment Share on other sites More sharing options...
andybeau Posted July 30 Report Share Posted July 30 13 minutes ago, Nigel Clark said: Yes, would be fun but getting everything connected and working properly involves some serious work! Nigel Adds to the fun and sense of achievement 😉 Link to comment Share on other sites More sharing options...
MJH2454 Posted July 31 Author Report Share Posted July 31 23 hours ago, Nigel Clark said: Had you considered staying with your present engine and giving it a few tweaks? The Mk4 1300 isn't the most powerful Spitfire engine but it will respond well to a slightly hotter camshaft e.g. from the Mk3, plus a stage 2 head and suitable needles in the carbs. Nigel My understanding was that the HS2's were marginal if you start playing with the head and cam and that you would also need to upgrade to HS4's to get the benefit of the mods? Also will this not still give me a revy engine which is not really what I'm after Link to comment Share on other sites More sharing options...
johny Posted July 31 Report Share Posted July 31 yes torque mainly comes from capacity (ask the yanks) and gas flow improvement, although good for max HP, can actually reduce pull at lower revs... Link to comment Share on other sites More sharing options...
Nigel Clark Posted July 31 Report Share Posted July 31 3 hours ago, MJH2454 said: My understanding was that the HS2's were marginal if you start playing with the head and cam and that you would also need to upgrade to HS4's to get the benefit of the mods? Also will this not still give me a revy engine which is not really what I'm after The HS2 carbs were good for 75bhp on the Spit Mk3 (and incidentally, a pair of HS2s delivered the same power output on the 1275cc Mini Cooper S). The Spit Mk4 in standard form makes only 63bhp, so with the right needles, these carbs will be perfectly adequate. HS4 SUs may be beneficial if you're looking for more than 80bhp, which would need a longer dwell camshaft. The end result could be a sacrifice of low end torque, and practical everyday driveability in order to get a little more at the top of the rev range. Nigel Link to comment Share on other sites More sharing options...
thescrapman Posted August 1 Report Share Posted August 1 If you want bags or torque, why not go for a 1700. Link to comment Share on other sites More sharing options...
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