One for the petrol heads....

[nero279]

.... What manifolds do ya reckon will work best on a modified 3.9 Efi rover v8?

Standard mild steel ones than in theory should be balanced? or a pair of 4 branch stainless ones that are quite clearly not balanced?

Modifications if they make any difference - Rover 3.5 kent cams high lift cam kit & vernier pulleys, performance gaskets all round, K&N type filter (soon to be replaced to make way for a snorkel, 10mm quadcore HT + king leads, flamethrower ignition coil, some other ignition system stuff, FSE boost valve, and uprated fuel pump.

Opinions?

[surfenstein]

.... What manifolds do ya reckon will work best on a modified 3.9 Efi rover v8?

Standard mild steel ones than in theory should be balanced? or a pair of 4 branch stainless ones that are quite clearly not balanced?

Modifications if they make any difference - Rover 3.5 kent cams high lift cam kit & vernier pulleys, performance gaskets all round, K&N type filter (soon to be replaced to make way for a snorkel, 10mm quadcore HT + king leads, flamethrower ignition coil, some other ignition system stuff, FSE boost valve, and uprated fuel pump.

Opinions?

what block do you have,i.e engine number.found on the left hand bank at the front by number one plug.is the engine going to be fitted into the surf?do you want carb or fuel injection?,what sort of budget do you have in mind?do you want low down torque and power or do you want an all out racer like mine?the rover v8 can pretty much be tuned to whatever your requirements are.and they are also pretty much bullet proof.if you have room you would be better off going for a set of custom made block hugger manifolds,using an unbalanced exhaust system.if not the 3.9 ambulance manifolds are pretty good.i used mine back to front and opposite sides to clear the steering column.there are a number of different cam types from mild tune to fast road and race you can have hydraulic lifters or solid lifters.but be very carefull when chosing a cam they work well with other mods like gas flowed heads,ported polished ,bigger valves,etc.if you have the high compression engine.you can get a set of composite head and valley gaskets.these are slightly thicker than the standard tin gaskets (hence will affect the compression ratio of the engine) .as for ignition i use a mallory distributor with an optical pickup and ignition amplifier.its never let me down.it looks like you wanna keep the fuel injection so you will also need part of the wiring loom from the donour vehicle.if you go carbs you have an option of two four barrel carbs in the form of a webber 500 or the good old 390 holley.inlet manifold i would go dual plane offenhouser 360.or you can go the su route.you will also need an electric fuel pump and fuel regulator.for any of these carbs.rhoads do a very good dual timing chain and gears for this engine well worth investing in.and a vernier pully lots on the market,i would get one from the manufacturer of your choice of cam,there is so much you can do to this engine,i could write an essay on it,but hopefully there are a few pointers here for you to be going on with.

[nero279]

Unfortunately no it's not going in the surf, but the one that's currently in the LR 100" hybrid may be going in the surf once it's been stripped and rebuilt.

Engine number has been chiseled off, believed to have been done for insurance purposes as the range rover it came out of was supposed to be a 3.5 and it turned out to be a 3.9 block. Apparently the heads are the same but we think it has a 3.5 head on. Hoping to run it as an efi, and we already have the full engine loom.

It's purely being built as an offroader so i guess the torque is more important than all out power. The engine has just been fully stripped and rebuilt with new almost everything. Composite gaskets, kent cams high lift cam kit and vernier pulley. It should be going back in the vehicle tomorrow, then we just gotta fit the fuel tank + a new pump, it has an adjustable fuel regulator in the form of an FSE power boost valve which will hopefully make setting up the fuelling a little easier.

The only thing that hasn't really been decided yet is which manifolds to put back on as we already have both the standard ones or a set of used custom stainless 4 branch ones that are not balanced? If I knew it was all running well and set up right i'd go for the unbalanced ones, but will it make any difference while setting up the fuelling etc. any thoughts?

Neither of us that are doing this have done much with v8s before at all, other than broken one - hence why we are replacing it.

Once the engines done we can start prepping it as a challenge type vehicle which was the aim when the vehicle was purchased back last summer.

[surfenstein]

Unfortunately no it's not going in the surf, but the one that's currently in the LR 100" hybrid may be going in the surf once it's been stripped and rebuilt.

Engine number has been chiseled off, believed to have been done for insurance purposes as the range rover it came out of was supposed to be a 3.5 and it turned out to be a 3.9 block. Apparently the heads are the same but we think it has a 3.5 head on. Hoping to run it as an efi, and we already have the full engine loom.

It's purely being built as an offroader so i guess the torque is more important than all out power. The engine has just been fully stripped and rebuilt with new almost everything. Composite gaskets, kent cams high lift cam kit and vernier pulley. It should be going back in the vehicle tomorrow, then we just gotta fit the fuel tank + a new pump, it has an adjustable fuel regulator in the form of an FSE power boost valve which will hopefully make setting up the fuelling a little easier.

The only thing that hasn't really been decided yet is which manifolds to put back on as we already have both the standard ones or a set of used custom stainless 4 branch ones that are not balanced? If I knew it was all running well and set up right i'd go for the unbalanced ones, but will it make any difference while setting up the fuelling etc. any thoughts?

Neither of us that are doing this have done much with v8s before at all, other than broken one - hence why we are replacing it.

Once the engines done we can start prepping it as a challenge type vehicle which was the aim when the vehicle was purchased back last summer.

no the exhaust manifold wont make any difference to fuelling.if your engine was tuned like mine then i would of said yes,but only a slight change in fueling if your heads arnt port matched and gasflowed you will be fine.if it were me building the engine and the fact that you are using composite gaskets i would of had the heads skimmed first just to lower the comp ratio a little further,but that shouldnt matter to much.oh and dont forget to set the valve lash properly,this has a dramatic effect on engine performance and wear.sounds like a good project,good work.were the heads already fitted to the block,and was the engine fuel injected.the reason i ask is that the fuel injected heads have a little notch on them where the injectors fit.standard heads dont have this notch so you will need to file it out.

[nero279]

Thanks vatch...er....surfenstein, the head has been swapped, both the head that was on and the head that's on now are EFI heads.

[v8 jeep]

If you want a good set of headers that are for limited space then i would recomend headman header range rover ones, I use them and are a good set and do the job. Real steel sell them for about £156 ish.

[nero279]

Engines in and running! Sounds sweet as a nut. Only problem we had was that the 4 branch manifolds didn't meet the rest of the exhaust! About a 3" gap 1 side and 1" the other. The engine wouldn't run right with the gaps as there was virtually no backpressure, so we've sleeved the gaps and spotwelded in place for now, then filled with putty to get it running, should be properly sorted tomorrow if not sometime next week.