What Cam?

Burtie2904 · Jan 4, 2019

Before I start, yes I know this has been done before but didnt quite find the right answer.
Basically after having a look at my cam, its got 95k and is worn. So its time for a new one but i have decided not just to go for the standard one.
One important factor for me is retaining any sense of fuel efficiency i currently have, with a worn cam i get 18mpg on long runs and dont want it to get any worse thats for sure, so if getting a nice torquey cam will make it noticeably worse i wont bother and will just go with a 3.9 cam.
My question is with fuel efficiency in mind (long motorway runs), no regular towing and wanting a bit of extra oomph all over, in experience which are the good cams to go for.
I was thinking the Kent h180 but some people say thats more suited to autos? Otherwise havent heard much about the piper torque max ones.
I like the look of the real steel hurricane and cyclone (cheaper), but they seem to be more fast roadey or am i wrong?
or is it not worth the bother and i go with a 3.9 cam and save £.
BTW is a stock 3.5 in a 1988 110

Henry_b · Jan 4, 2019

Piper 270 or 285 would get my vote!

classic kev · Jan 4, 2019

I put a Kent H180 in my 3.9 Range Rover Classic. I don't bother measuring fuel consumption, it's a bit pointless. However, it seems to have more mid range power and overall, I would say not a bad way to go although I have read that for a 3.5, using a standard 3.9 cam is a good upgrade. As part of the cam swap I also played around with the CO trim on the efi and increased the ignition advance so if you do swap to anything other than a stock cam, you should consider looking at ignition timing and fuelling as both would likely be beneficial in optimising the performance of your cam both in terms of power and fuel consumption. HTH.

kermit_rr · Jan 4, 2019

I did some reading before i swapped mine in the 4.0 Thor and a few people seemed to suggest a milder cam offering a bit more torque lower down at the expense of top end power could be more useful day to day but in the end i stuck with the standard cam
Whatever you put in will be an improvement over an old worn one

discool · Jan 4, 2019

“wanting a bit of extra oomph” “with fuel efficiency in mind”

To increase the engine performance you will need to put fuel/air mixture into it, therefore you will need a different cam with a ‘fast road’ quick opening slow closing cam profile, both fuel induction and exhaust extraction will need attention also along with the cam, plus electronic ignition will also help if you don’t already have it.
Why not remove the 3.5 and install a 3.9 simples

Henry_b · Jan 4, 2019

pah go full fat with a built 4.6

300+hp

and over 500nm of torque

Burtie2904 · Jan 4, 2019

discool said:
“wanting a bit of extra oomph” “with fuel efficiency in mind”
To increase the engine performance you will need to put fuel/air mixture into it, therefore you will need a different cam with a ‘fast road’ quick opening slow closing cam profile, both fuel induction and exhaust extraction will need attention also along with the cam, plus electronic ignition will also help if you don’t already have it.
Why not remove the 3.5 and install a 3.9 simples

Thats the long term plan, but atm I'm happy with the 3.5 and can't really afford a good condition 3.9. and I know the " i want better fuel consumption" and more power sounds silly but remember at the moment I've got crap fuel consumption because I have to have a heavy foot with such a worn cam. So basically just saying I don't want anything too wild.

Burtie2904 · Jan 4, 2019

Henry_b said:
pah go full fat with a built 4.6

300+hp and over 500nm of torque

Tbh when I get to that stage in a few years I plan on doing a built twin turbo 4.0, forged pistons, pair of T25 little turbos and tonnes of midrange torque. Can't wait ( and yes that's in a few years when I don't have to worry about mpg anymore )

Burtie2904 · Jan 4, 2019

classic kev said:
I put a Kent H180 in my 3.9 Range Rover Classic. I don't bother measuring fuel consumption, it's a bit pointless. However, it seems to have more mid range power and overall, I would say not a bad way to go although I have read that for a 3.5, using a standard 3.9 cam is a good upgrade. As part of the cam swap I also played around with the CO trim on the efi and increased the ignition advance so if you do swap to anything other than a stock cam, you should consider looking at ignition timing and fuelling as both would likely be beneficial in optimising the performance of your cam both in terms of power and fuel consumption. HTH.

Yeah I like the sound of the h180, and yes while I'm still on carbs atm, will change to efi eventually, I'm going for a rolling road tune after, timing and needles sorted etc.

Henry_b · Jan 4, 2019

Nah keep her carb'd a nice Holley set up would go.

Just watch the rest of the drivetrain

Burtie2904 · Jan 6, 2019

Someone else recommended me after a long chat to get a kent h200 as its a manual and can use the revs. Would this be a little much for a 3.5?

Henry_b · Jan 6, 2019

Burtie2904 said:
Someone else recommended me after a long chat to get a kent h200 as its a manual and can use the revs. Would this be a little much for a 3.5?

The RV8 is a torque machine mostly down low 2600rpm torque peak IIRC if built properly..

TBH unless it's a ferrari there is no need to build a screamer..

Its an old 110 that just lugs around not really any point revving the tits out of it to get power

Burtie2904 · Jan 6, 2019

Henry_b said:
The RV8 is a torque machine mostly down low 2600rpm torque peak IIRC if built properly..

TBH unless it's a ferrari there is no need to build a screamer..

Its an old 110 that just lugs around not really any point revving the tits out of it to get power

Yeah thanks Henry, I completely agree im just not experienced enough to know which cams will move the torque and power significantly up the rev range. So So are saying the h200 would do that? They call it a (sports torque cam still).

norseman · Jan 6, 2019

Remember Newtons third law 'for every action there is an equal & opposite reaction' Do these cams actually increase power/torque or simply move it to a different point in the rev. range? For example, the figures for the 3.5 efi version of the Disco 1 show a greater peak torque than the RRC & at lower RPM.
nb: does anyone have the valve timing figures for the 3.9, so I can compare them with the 3.5efi?

discool · Jan 8, 2019

norseman said:
Remember Newtons third law 'for every action there is an equal & opposite reaction' Do these cams actually increase power/torque or simply move it to a different point in the rev. range? For example, the figures for the 3.5 efi version of the Disco 1 show a greater peak torque than the RRC & at lower RPM.
nb: does anyone have the valve timing figures for the 3.9, so I can compare them with the 3.5efi?

Maybe that's because of the difference in their EFI system, but maybe not.
Valve Timing ............……...............……...............……...…….Inlet & Exhaust
Opens .............................................................................. 32°BTDC 70°BBDC
Closes .............................................................................. 73°ABDC 35°ATDC
Duration ........................................................................... 285° 285°
Valve peak ....................................................................... 104°ATDC 114°BTDC

norseman · Jan 8, 2019

Thanks for that Discool.

What Cam?

Burtie2904

Active Member

Henry_b

Think outside, no box required.

classic kev

Well-Known Member

kermit_rr

Very

discool

Well-Known Member

Henry_b

Think outside, no box required.

Burtie2904

Active Member

Burtie2904

Active Member

Burtie2904

Active Member

Henry_b

Think outside, no box required.

Burtie2904

Active Member

Henry_b

Think outside, no box required.

Burtie2904

Active Member

norseman

Well-Known Member

discool

Well-Known Member

norseman

Well-Known Member

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