Vulcan Engines 185 Uxbridge Rd. Hanwell London W7 3TH---Telephone 0208-579 3202/2988-Fax: 0208-579-7390 www.vulcanengines.com 26 Maxiflow Lead Free Cylinder Heads Normal 4 star petrol is no longer available.  The replacement ‘LRP’ is not suitable for performance engines. Therefore you need to address this problem now! By far the best way to run your engine on Lead Free fuel is by letting us convert it as described below.  Please
bear in mind this is the method that every Car major manufacturer in the world uses, as against using additives
or any other device. Lead in petrol served two purposes. Firstly it reduced the temperature
of  the  combustion  allowing  the  use  of  a  relatively  high  compression
ratio.  This  leads  to good burning of the mixture and in consequence an
efficient engine. It also reduced the temperature of the exhaust valves
and seats. The inlet side is cooled by the in coming charge of petrol.  The second purpose equally  important was that the lead lubricated the
valves and valve seats eliminating any chance of seizure. Without the lead in petrol you therefore have two problems. The first
is your compression ratio. Most Lead Free fuels have a relatively high-
octane  value  and  therefore  this  is  not  generally  much  of  a  problem.
However  in  some  instances  you  might  have  to  retard  the  ignition
timing.                                                                               However the second problem i.e., the lack of lubrication is potentially
                                                                              very serious. Without this lubrication we know from experience most
                                                                              engine will sustain serious  damage within 1000 miles!  The first sign
of problems is that you will find your tappet clearances closing up very rapidly.  The reason being that without
the lubrication that 4 star petrol provided the exhaust valves would begin to ‘bang’ themselves into their seats. To  allow  these  engines  to  run  much  without  this  lubrication  you  need  very  hard  exhaust  valves  and  exhaust
seats. To achieve this we use stainless steel exhaust valves and special ‘Moly Chrome’ exhaust seats. Also if
the cylinder head does not have valve guides fitted, as is the case with most Ford heads, these need to be fitted.
The reason being stainless steel valves are not compatible with normal cast iron. With this conversion you can
run the engine entirely on lead free fuel without worry. One  of  the  most  commonly  asked  questions  is  will  the  valve  seats  fall  out?  The  answer  to  that  is  No!  To
machine   the   cylinder   head   to   accept   these   seats   we   use   a   machine   manufactured   by   Serdi.   Major
manufacturers such as BMW, Rover, and Lotus use these expensive purpose made machines. It allows the use
of very tight tolerances and a perfect fit. All the heads in followings list are fully reconditioned with all new valves, guides and valve springs. In the case
of the performance heads they will run without any perceivable power loss in comparison to their leaded
equivalent.