Osbert Posted October 17, 2014 Report Share Posted October 17, 2014 I have a fairly standard 4a, it has a non standard inlet manifold, standard Su's and from what I understand a standard engine. I have had the suspension all uprated with adjustable shock conversion and a slightly stiffer springs. I have been thinking of just trying to uprate it a bit in the "BHP department". Should I go for a couple of webers, if so what sort, a livelier cam perhaps? If I am doing this do I need to update the diff and drive shafts? And maybe disc brakes on the back. I'm not looking for rally performance just making it a bit livelier. Suggestions welcome. Quote Link to post Share on other sites
Geko Posted October 17, 2014 Report Share Posted October 17, 2014 The basic package would include: Weber/Mikuni/Dell'orto, fast road cam, 4/1 extractor for a good 10-15 BHP gain. More than that R-boys will take over... Quote Link to post Share on other sites
Tr4Tony Posted October 17, 2014 Report Share Posted October 17, 2014 Hi I wouldn't bother with webers unless your going over 140 bhp maybe even as high as 150 bhp, SU' s HS6's will cope up to that If the head, cam and exhaust are good for the power and nicely matched. I'd say spend your money there and on a decent flywheel & clutch so that you gain torque and tractability not on paper bhp. Talk to someone sensible about what you can afford to do without going bonkers .... Otherwise you're on the road to lots of shiny things. Regards Tony Quote Link to post Share on other sites
Motorsport Mickey Posted October 17, 2014 Report Share Posted October 17, 2014 Tonys on the mark (as usual), nothing against Webers and other bling carbs but for the gains you are after the SUs will cope easily and deliver excellent mid range torque. If you want good road performance screw some 89mm pistons and liners into it, excellent increase in mid range torque which makes it very driveable on the roads, and they are bullet proof. Oh...and whilst inside the engine balance all the reciprocating bits, makes a big difference to smoothness. Mick Richards Quote Link to post Share on other sites
Guest Posted October 18, 2014 Report Share Posted October 18, 2014 You don't need disks at the back. Alfin drums perhaps, but I doubt if that's something you need on the open road. If you want to improve you TR's brakes, I would turn to a dual brake system (two cylinder system = more safety) and perhaps a front brake upgrade. There's enough info on that here on the forum. The standard flywheel of a TR is a heavy lump. It can loose a few kilos without any problem. For most of us, removing weight from the flywheel is a professional job. Choose your engine builder carefully and make sure the whole set up is perfectly balanced! And that he knows what he's doing. Keep in mind that there's a fan at the front as well that is part of the 'balancing act' as well. A well-balanced engine will run smoother and often more quietly. Menno Quote Link to post Share on other sites
littlejim Posted October 18, 2014 Report Share Posted October 18, 2014 (edited) Dare I mention an electric water pump? After fitting one you can get rid of the mechanical one and blank the space off. Probably save a couple of horsepower from not having the thing thrashing around all the time. (Slight loss of weight too.) Edited October 18, 2014 by littlejim Quote Link to post Share on other sites
Peter Cobbold Posted October 18, 2014 Report Share Posted October 18, 2014 If you only want a bit more torque and power then a supercharger is out. Quote Link to post Share on other sites
ChrisR-4A Posted October 18, 2014 Report Share Posted October 18, 2014 Hi, firstly your engine needs completely stripping and crack testing for crank, head block and conrods. Also all threads especially studs in block need checking, no good spending money on lots of bling bits if it all falls apart! It may be running ok at the moment but if you just bolted some Webers on this could be the straw that breaks the camels back! All these engines are very old now and you will be very lucky if some of the above items dont need attension. Regards Chris Quote Link to post Share on other sites
Tr4Tony Posted October 18, 2014 Report Share Posted October 18, 2014 Hi, firstly your engine needs completely stripping and crack testing for crank, head block and conrods. Also all threads especially studs in block need checking, no good spending money on lots of bling bits if it all falls apart! It may be running ok at the moment but if you just bolted some Webers on this could be the straw that breaks the camels back! All these engines are very old now and you will be very lucky if some of the above items dont need attention. Absolutely. More grunt = faster failure rate ... And Micks points on 89mm pistons and liners is a good one, 100 cc for free and a good choice I'd you need to replace yours anyway. I'd be caution of the electric water pump as if the electricity stops and it goes dead, you'll cook the engine. A 4cylinder head gasket won't tolerate much superheating, and liners crack and /or move, so I tend not to take that risk. A well toleranced big bearing standard 4 vane pump in an alloy housing is absolutely the best solution IMHO. Regards Tony Regards Tony Quote Link to post Share on other sites
Allan Westbury Posted October 22, 2014 Report Share Posted October 22, 2014 Hi Osbert, as you may have guessed there is more than one way of skinning a cat! When looking at upgrading my engine a bit as you are I was advised to look at the'breathing' first. I have kept the SUs but fitted uprated air filters, a sports manifold and Phoenix straight through exhaust. Next step was enlarged pistons, fast road cam, balanced crankshaft, flywheel and propshaft. When fitting an uprated camshaft you will need to change the SU needles,this was done on the rolling road. I have kept the mechanical water pump but replaced the mechanical fan with electric. When tuned on Wiltshire Garage's rolling road it pulled 140 HP but will still pull away happily at 30mph in top gear. I was led to believe that there is no point on spending money on the engine internals until the airflow is optimised. As far as brakes go I have seen no need to upgrade the rear drums, just make sure you have good pads in the front. Cheers, Ollie Quote Link to post Share on other sites
Tr4Tony Posted October 22, 2014 Report Share Posted October 22, 2014 Hi Mintex m1144 pads and shoes are a great balance of cost and performance as per Ollie's email above, and need no special bedding in procedures etc. Regards Tony Quote Link to post Share on other sites
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