engine compatability and the best way to go

General Chat About Engine Build

Moderator: phpBB2 - Administrators

Post Reply
mug1
Newbie
Newbie
Posts: 1
Joined: Sun Mar 12, 2017 3:48 pm
Location: horsham

engine compatability and the best way to go

Post by mug1 »

hi everybody. would like some opinions on my dilemma,all info gratefully recived.blew up my old p6 forgot about high compression and petrol situation ,i think it pinked its self to death.just purchased rebuilt short engine with 9.75.1 +40 pistons and 285 piper cam.if i use this cam i belive it can only be used with stage 1 heads,thats engine 1.engine 2, went to the swap meet looking for cylinder heads found engine,range rover 4.6 cast in fuel injection top casing and completely lost the plot ,now crazed with 4.6 power forgot to look at engine number and crossdrilled block fitting,idiot or other much stronger word involving loss of eyesight as young boy.good news! the heads are hrc 2479 and look to be ok.bad news!its a 3.9 not 4.6 but in fairly good nick borewise,rings and bearings need change ,but ok.cracked blocks and liner problems an unknown. Questions.will the hrc 2479 heads and rockergear fit the 3.5 and should they have been fitted to the 3.9 in the first place? would the piper cam work with the hrc 2479 heads if i used double springs or the 1 coil cut off type and any cam follower upgrade nessercery or should i fit 3.9 cam.the heads will be fitted with composite gaskets.should i use the rebuilt 3.5 or the 3.9 which has lower ratio of 9.35.1thanks



GDCobra
Knows His Stuff
Knows His Stuff
Posts: 377
Joined: Sat Feb 04, 2017 9:21 am
Location: North West

Post by GDCobra »

Don't know about the cam but surely the 3.9 engine is going to be better in other respects?
It'll have a better front cover (assuming it's nof the high water pump type) with higher capacity oil pump, better heads with bigger ports (and possibly valves), better oil seals on crank and just generally newer. It's also fuel injected if you want yo go that way.

unstable load
Top Dog
Top Dog
Posts: 1278
Joined: Mon May 04, 2009 6:53 am

Post by unstable load »

All Rover heads will fit all Rover blocks in standard form. The newer the head the better.
Stage 1 modification means a lot of things to different people, but if you check the build step by step as you go along you will soon see if there is any sort of issue with the cam and valves either becoming springbound or hitting the pistons.
Cheers,
John

Post Reply

Return to “Engines Area”