Thebishop Posted September 27, 2016 Share Posted September 27, 2016 Hi lads need a bit of advice please. I have 1.8 ohc in my manta is there anyway to increase bhp. Would be willing to spend maybe €500 on engine. I would love to go down redtop route but it just seems to work out way too expensive. Regards Quote Link to comment Share on other sites More sharing options...
rutts Posted September 27, 2016 Share Posted September 27, 2016 Bike carbs, cam change, bigger valves in head. Free flow exhaust. Fit in reverse order. Quote Link to comment Share on other sites More sharing options...
Thebishop Posted September 27, 2016 Author Share Posted September 27, 2016 Thanks rutts, can I ask which bike carbs and what about manifold? What's valves would suit. Regards Quote Link to comment Share on other sites More sharing options...
Shug Posted September 28, 2016 Share Posted September 28, 2016 (edited) R1 carbs were the most popular but others will work fine. Use the bike fuel pump as well. You can get a manifold from Bogg Bros who can also advise you on carbs. I'm not recommending them beyond letting you know they do that kind of thing. Many other folk are perfectly happy with them. Edited September 28, 2016 by Shug Quote Link to comment Share on other sites More sharing options...
rutts Posted September 28, 2016 Share Posted September 28, 2016 Bike carbs most used ar r1 and zzr1100. Lots of places doing inlets now search internet. Valves are 1.8 astra gte inlets or 2.0 seh engine inlets. Find a 1.8 astra gte cavalier cylinder head with cam and bolt it on. Exhaust i used ashley exhausts in birmingham/ walsall Quote Link to comment Share on other sites More sharing options...
Thebishop Posted September 28, 2016 Author Share Posted September 28, 2016 Thanks rutts I got a price from bogg brother of £600 for carb, manifold, fuel pump and a few other little bits needed. Plus then the parts you mentioned. What do you think of that? You wouldn't have any of the bits laying around would you? Quote Link to comment Share on other sites More sharing options...
Thebishop Posted September 28, 2016 Author Share Posted September 28, 2016 12 hours ago, Shug said: R1 carbs were the most popular but others will work fine. Use the bike fuel pump as well. You can get a manifold from Bogg Bros who can also advise you on carbs. I'm not recommending them beyond letting you know they do that kind of thing. Many other folk are perfectly happy with them. Thanks shug got on to bogg brothers today. Anyone know where I can get these parts easily. Quote Link to comment Share on other sites More sharing options...
mantasrme Posted September 29, 2016 Share Posted September 29, 2016 £600 sounds a high price to me, their manifolds were about £170 last i heard. So add carbs a pump and a filter and you shouldn't be at £600 The problem is that R1 carbs are have got so popular for car conversions from articles in magazines that their price has gone way up. You used to get R1 carbs for £50 a set but now you are lucky to get them for £100 and more like £150 on ebay. Also whenever someone asks about bike carb conversions Bogg brothers always gets mentioned because its the most common place to go and has been featured in several magazines over the years, which has seen their prices go up a bit from the old days when Dave ran the place. Part of the reason R1 carbs are so popular is because every R1 made with carbs had the same 40mm mikuni CV carb fitted so its easy to know what you are buying. However other bikes had 40mm or 39mm or 38mm, but only certain models in certain years had the right carb type and size, and they may have had different spacing to match the engine. A bit of time spent on e-bay looking at the adverts and asking the seller questions about measurements can produce wonders. I got some 39mm mikuni carbs from a suzuki GSXR for £40 end of last year. The power you will get from a 39mm or 40mm is not going to be different until you have such a highly tuned engine that you are putting out way over 200bhp. Also as its only a 1.8 you are playing with and then only a slightly modified one you do not need 40mm you could run 36mm (which are a lot more common/cheap) A set of bike carbs at 36mm are the same internal size as a set of 40dcoe carbs (as they have to have chokes in and the biggest is 36mm) but the bike carb gives a better flow and is more drive able with the CV design. So while it may not be the maximum performance you could add 36mm would be a huge improvement over the standard varijet carb and still better than bolting a set of 40mm dcoes on. If i was looking at a £600 bill for carbs before i even found a cam or bigger valves i would seriously consider changing the engine instead. All the work you do to the 1.8 will prob only see you to 115 or so bhp, so a 2.0ohc on injection from a later cavalier/cartlon is already there, or if you get an SEH thats 130bhp. Both of which take your current exhaust manifold, sump, mounts, water pipes and everything else. No heater mods required or moving of dizzys like the c20xe. The only issue is that you would need an injection fuel tank. If you have a coupe thats easy enough to get hold of, but if you have a hatch it is more of a problem. However you can get carb tanks modified at specialists to convert them to injection. At the end of the day it depends how much power you want, how much work/effort you are willing to put in, and how much you are willing to spend. 1 Quote Link to comment Share on other sites More sharing options...
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