Hi just for the record. I have today used a large surface plate and some accurately machined pieces of tool steel to compare a Commer cam shaft with an iron head Hunter cam shaft and come to the conclusion they are identical. Not what I was expecting, now debating getting a faster cam made up for Smurf!
Different camshafts....................
- Thread starter old camper
- Start date
Keep thinking of swapping mine - I’ve got an alloy hunter engine but was a single carb (now single su) so got the worst camshaft it could have. Sure a swap out would see 15-20 HP more from the 75 atm
Just never swapped one - not sure how easy it is and if can be done in situ
JJ Autosleeper
Active Member
I’m not sure there are any performance camshafts for the cast iron head engines in the Rootes range. I think they made them all for the alloy head engines. But I may be very wrong. I’d try Paul Marshall at Arrow 5 in Southampton for this one. He deals with a lot of Rapiers. 01489 877580. Martin will know too no doubt.
The trouble is where do you stop? I just read the Vizard book on the A series. I think I will stick with the standard cam, clean up the ports and valves a bit.
The new pistons have a smaller dish in them (5cc rather than 15cc) so that will bring up the compression ratio abit, plus a light skim, will, probably make some difference. It would be btter to start with an Aluminum head engine from a Rapier really!
Thank you everone for your interest.
The new pistons have a smaller dish in them (5cc rather than 15cc) so that will bring up the compression ratio abit, plus a light skim, will, probably make some difference. It would be btter to start with an Aluminum head engine from a Rapier really!
Thank you everone for your interest.
JJ Autosleeper
Active Member
How did you new piston/light skim and polishing plan go? I’m thinking of doing mine sometime. I have the standard 1725 engine and cast iron head. Only change is new stainless exhaust and Weber 34ICT.