BiTurbo228 Posted December 3, 2015 Share Posted December 3, 2015 Just a quick thing that popped into my head.After my (rather expensive) Spit6 project I plan on doing a much more basic engine conversion on another Spitfire using an 1850 slant-4.Looking at the engine and reading around it looks like the dashpots would foul on the bonnet, meaning you'd need to put unsightly bulges in it (works on Elans but less so on Spits for some reason, not sure why).However, I read somewhere that for HS6s there are two different heights of dashpots, a standard one and a low-profile.Does anyone know if there's a similar thing for HS4s from another car? Can't seem to find any info online... Quote Link to comment Share on other sites More sharing options...
nang Posted December 3, 2015 Share Posted December 3, 2015 I've read somewhere,( forgotten where) that existing dashpots can be shortened in a lathe.Will try to find details, or you probably could google it.Tony. Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted December 3, 2015 Share Posted December 3, 2015 I'm not aware of any car with HS4 , HIF4 or HIF38 carbs that had low profile dashposts. I expect they can be shortened in the same way that the larger carbs sometimes are. Rethreading is the trickiest part.Another option to consider is that the early 1850s were fitted with lower profile Strombergs....Nick Quote Link to comment Share on other sites More sharing options...
BiTurbo228 Posted December 4, 2015 Author Share Posted December 4, 2015 Quoted from nang I've read somewhere,( forgotten where) that existing dashpots can be shortened in a lathe.Will try to find details, or you probably could google it.Tony. Ah that might be an idea. Shall give that a google...Quoted from Nick Jones I'm not aware of any car with HS4 , HIF4 or HIF38 carbs that had low profile dashposts. I expect they can be shortened in the same way that the larger carbs sometimes are. Rethreading is the trickiest part.Another option to consider is that the early 1850s were fitted with lower profile Strombergs....Nick Would you shorten the top of the dashpot or the bottom? I suppose the top would be easier to rethread. Shall have to do some research.Those Strombergs might just do the trick though. I'll see if I can cheaply source a pair.How do they compare to SUs? Maintenance and performance-wise... Quote Link to comment Share on other sites More sharing options...
Jonny-Jimbo Posted December 4, 2015 Share Posted December 4, 2015 Quoted from BiTurbo228 How do they compare to SUs? Maintenance and performance-wise... Interesting question - some people swear by SU and some by Strongbows. I think a lot of this stuff comes down to personal preference, knowledge and familiarity. I suggest in this situation see if you can get a set of the low bodies from an 1850, even if it's just borrowing them from someone that's doing a restoration so you can see if they fit before splashing the cash.I'd have said that a standard carb is going to perform more robustly than a modified one - as soon as you modify something unreliability sets in unless you thoroughly engineer it. Quote Link to comment Share on other sites More sharing options...
BiTurbo228 Posted December 4, 2015 Author Share Posted December 4, 2015 Quoted from Jonny-Jimbo Interesting question - some people swear by SU and some by Strongbows. I think a lot of this stuff comes down to personal preference, knowledge and familiarity. I suggest in this situation see if you can get a set of the low bodies from an 1850, even if it's just borrowing them from someone that's doing a restoration so you can see if they fit before splashing the cash.I'd have said that a standard carb is going to perform more robustly than a modified one - as soon as you modify something unreliability sets in unless you thoroughly engineer it. Gotcha. When I come round to doing it I'll see if I can take some measurements or borrow a set to trial-fit.Actually, just seen a set of 3 Stromberg 175s on eBay for £15! Might pick them up and do some measuring plus, they should be good for the 115bhp I'm looking for (according to a thread by our good friend Gareth T the 150s top out at about 105bhp...) Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted December 4, 2015 Share Posted December 4, 2015 You shorten the top of the dashpot where the damper screws in, and the damper rod and the guide cylinder of the piston.Nowt wrong with Strombergs when in good working order. Historically, spares used to be much harder to get but I think that is better now. Possible issues include- Not nearly such a wide range of needles available - which could be an issue for non standard fitment.- Later ones have some fairly wacky cold start enrichment and emissions control devices, which can be difficult to deal with.Nick Quote Link to comment Share on other sites More sharing options...
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