Quote:
Originally Posted by mitch1971
Yeah keep the standard exhaust for now. Once past the manifold there is very little to gain in performance so I wouldn't bother with the simons exhaust.]
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I would have to respectfully disagree with this. Any modifications to the inlet and exhaust system have to work in concert with each other: there is very little point in fitting a free-flowing manifold, porting and polishing the head, and then bolting it up to a standard exhaust. I know this from experience: before I had the exhaust system built for my car ( see best modifications thread), I was running my four-branch manifold linked to a standard exhaust system. (This was a necessary evil, so that I could drive the car to the exhaust centre.) Top speed with this set-up was an indicated 90 mph. With the system I have now, and NO other mods since ( other than re-adjusting and balancing the carbs) , the car will now run off the clock ( on a private road, of course! I would'nt use the car for pouncing on unsuspecting moderns on the motorway, or anything like that, oh no....). More importantly, with the standard exhaust the engine did not rev anything like as freely through the gears as it does now.
Just because the market-leading "sports" exhaust will not achieve this sort of performance, does not mean that no exhaust system modifications are worthwhile.
My father's B18 Ruddspeed used to cruise quite happily at 100 and would easily hit 115. I don't believe this relatively mild sixties tune would have achieved this kind of top-end performance with a standard system.
There is an awful lot of good advice on this thread, to which I will now add the following: PLAN what you are doing carefully, decide what you want to achieve, then write the "wish list" of parts and labour required to achieve this. If you're on a budget, acquire the parts as and when, and basically spend a year or so "parts-collecting". Meanwhile, enjoy your nice standard Volvo. When you're ready, build your engine to your planned requirements. I can assure you that this approach, whilst requiring patience, is far more likely to yield the results you're after.
Some modifications ( like electronic ignition) may be expected to improve the running of a bog-standard engine, but if you're modifying the inlet, exhaust, head, cam etc, then do it all at once, and set your engine up once. Finally, all the very best of luck with it! It is amazing what these old engines can do with the right help....
I should add, that the cheapest and easiest thing to do would be to build the engine to late P1800S spec., or 123GT spec. This would give an immediate, noticeable ( and easily achievable) improvement over the B18 A spec. Might be a good "Stage 1", after you've done all the usual "Stage zero" stuff.