Please help if you can ,I have a type 4 1700 with twin 44 HPMX Empi carbs ,CB mild road cam, large bore empi manifold and exhaust and the usual obligatory add ons ---- deep sump,large remote oil cooler etc etc . Its at the moment having a new set of pistons after the last ones were put in the wrong way [ HONEST ]. I just need some advise on weather its worth having the heads ported and flowed whilst its stripped ,the cost is really good -- £50 to £70 but is it worth doing .Will the gains be good ,bad or ugly, any ideas on bhp and drivability gains as a whole with this engine and setup Cheers all
you should get more bhp not a lot if i remeber from the old days of tinkering 5-10 bhp if your lucky and its done right,
Thanks ,i suppose 5 bhp isnt bad if you mean just from the head flowing.I was thinking overall about 80 bhp with the other upgrades ,maybe a little more but i really dont know much about gains on these engines .
if you have done other airflow mods already and a mild cam then yes porting your heads and match porting the large bore manifolds to the heads will defo help by how much only the dyno can tell!
at the end of the day its about flow ... the quicker the flow goes in and is able to leave the picton chamber once fired, so an extra 5bhp in the long run could save you more than the off set of having it done for 50 quid.
i guess more improvement could be made by using rampipes and carb mainifolds that are not the one size fits all to staighten and smooth the flow out and 1800 barrels and pistons ...deep sump and remote oil cooler may cool oil down too much
Thanks everybody ,i think i will get it done ,get it all matched up .I would love to overbore it but then how far do you go to keeping it drivable and economy?OH what to do .
You would take extra advantage of the polishing and porting if you went for larger inlet and exhaust valves aswell
