3.9 cam lift

[chrisandebreg]

can anyone tell me the measurement for cam lift if healthy when measured at the rockers on a 3.9 injected motor, also ideas and suppliers for replacement cam and thoughts on stages verses useability. all i want is a car that will stay at 100k's when aimed uphill. currently running gas and is running perfect just want to make sure its in ideal health. chris

[PhilipA]

The lift at the cam is .390inches.
I don't know how you could measure at the rocker as the hydraulic lifter would leak down if raised slowly. You could measure at the pushrod top but the same problem would exist.
The only real way would be to measure from the lobe.
As a guide my 196KK 3.9 cam had 0.5MM difference from back of cam to lobe tip vs new, so the differences between a worn cam and new are quite small.
And that resulted in (subjectively) quite a loss in high end performance .
Regards Philip A

[Pedro_The_Swift]

never do it at 100ks,,
at 2k revs the hp and twist just aint there for 2t of car,,

the same hill at 2500 rpm would just dissappear though,,,

[400HPONGAS]

oops

[400HPONGAS]

Sorry PhillipA , if it was .390 at the cam . that would shove the caps through the top of the valve guides
.390 times a rocker ratio of 1.5 would be .539 at the valve , very funny !
Try .260 , times 1.5 , that gives a total lift at the valves of .390 , a typical puny rover type lift . Considering the power comes from the Average lift , not the total , with its severe Port choking , it easy to see why the RV8 makes poor power !!
your run of the Mill type cam (Crow grind )
Part Number370771 Lobe Separation 111
Inlet Valve Lift .409
Inlet Opens22 B.T.D.C
.Inlet Closes56 A.B.D.C.
Exhaust Valve Lift .422
Exhaust Opens66 B.B.D.C.
Exhaust Closes16 A.T.D.C.
Inlet Duration 200 at 0.050
258 Advertised Exhaust Duration
205 at 0.050 262 Advertised

Lobe centers too wide
Lift too Low
To much overlap !!!

[400HPONGAS]

oops again !!

[Pedro_The_Swift]

what would you suggest 400hpongas?

[PhilipA]

OK you are correct with teh oops!
I didn't really take much notice.
I got the specs from here.


Ok, I've spent the evening reading and then spread sheeting the numbers and finally think I'm starting to understand correctly.... I hope.

Also, I was just looking at the Rover SD1 site.
They have some excellent cam info and a cam timing calculator. (Increasing Capacity (http://www.roversd1.nl/sd1web/cambase.html)). Dan, I plugged in your cam info and the numbers jived, except it says the cam is only 2 degrees advanced, not 4, when installed straight up. Any idea why the difference?

So, if I got it straight, in general:

1. The earlier the IO, the smaller the LSA, and the greater the OL -> the greater the power, but narrower the power band.

2. A later IO, wide LSA and small OL will give lots of torque over a wide power band, but less overall power.

3. In general the earlier the IO, the wider the duration.

4. The 50% duration numbers indicate the shape of the lobe, which in turn indicates how fast the valve opens and the ramp loading. A higher 50% number means the valve is open higher, longer so more fuel/waste get through.

5. The following numbers I assembled and/or calculated from the various posts I read (Thank you all!) and manufacturer info. It's comma deliminated and can be sucked into excel fairly easily.

Make,Number,IO,IC,EO,EC,Dur,LSA,OL,Valve lift ,Ret(+) Adv(-),RPM Range,Class ,Comments ,
Crane,H-194,10,54,59,15,244/254,112,25,.400/.430,2.5,,Road ,Economy cam only. Not to be used with comp. ratio over 8.75:1 ,
Rover,ERR5250,14,70,64,20,267/264,115,34,0.416,3.0,,Production ,4.6-litre - Hi Torque Cam,
Crane,H-204,15,59,65,21,254/266,112,36,.430/.456,3.0,,Mild Road ,Improvement over standard cam. Can be straight swap. ,
JE,JE101,20,65,65,20,265/265,112,40,0.430,0.0,,Road ,,
Kent,H200,20,64,69,25,264/274,112,45,.435/.460,2.5,,Mild Road ,For pre-SD1. Also good for automatics. ,
Isky,621262,21,61,61,21,262/262,110,42,0.445,0.0,2000 - 5000,Mild Road ,,
TA Perf,TA212,21,64,69,31,265/280,110,52,0.473/.485,5.0,1900 - 4900,,,
Crane,H-216,21,65,71,27,266/278,112,48,.456/.480,3.0,,Road ,Excellent all rounder. Good power increase across rev. range. ,
Piper,HR270,22,62,64,28,264/272,109,50,421/.439,3.0,,Road ,Flexible with good mid and top end improvement. ,
Crower,50230,22,58,69,17,260/266,112,39,0.446/.451,-2.5,1500 - 4000,Mild Road ,,
V8Tuner,AS-H180,23,59,59,23,262/262,108,46,0.441,0.0,1000 - 4500,Mild Road ,Hi torque,
Isky,621270,26,64,64,26,270/270,109,52,0.470,0.0,2000 - 6000,Fast Road ,,
Piper,V8BP270i,26,66,66,26,272/272,110,56,0.420/0.420,0.0,1500 - 6000,Fast Road ,Hi Torque EFI +22hp,
Crower,50231,27,63,74,22,270/276,112,49,0.451/.477,-2.5,1800 - 4500,Mild Road ,,
Piper,V8BP270,28,64,64,28,272/272,108,56,0.420/0.420,0.0,1500 - 6000,Fast Road ,for Carbs +24hp,
Kent,H180,28,64,64,28,272/272,108,56,0.439,0.0,1000 - 4500,Mild Road ,Good for automatics ,
Rover,ERR3720,28,77,66,39,285/285,109,67,0.390,5.5,,Production ,4.0-litre,
Woody’s ,RV10/RV15,28,72,76,32,288/280,112,60,0.448/.461,2.0,,,,
Rover,ERR5924??,30,75,67,37,285/285,109,67,0.390,3.5,800 - 4000,Production ,3.9-litre - use with CAMSHAFT THRUST PLATE ERR5926,
Rover,ERC2003,30,75,68,37,285/285,109,67,.390/.385,3.5,,Production ,3.5-litre SD1 / TR8,
Crower,50232,30,66,76,24,276/280,112,54,0.488/.490,-3.0,1800 - 4500,Fast Road ,D&D's Ulitmate Road Cam,
Kent,H214,31,73,80,34,284/294,112,65,.469/.494,1.5,1500 - 5000,Fast Road ,Very flexible. Good road camshaft. ,
SD1Web,,31.5,60.5,78.5,23.5,272/282,111,55,0.55,-4.0,1000-4500,Torque,,
Rover,ETC8686,32,73,70,35,285/285,109,67,0.390,1.5,800 - 3600,Production ,3.9-litre 36D 38D,
Woody’s ,RV10/RV15-2,33,67,79,29,280/288,111,62,0.448/.461,-2.0,1500 - 5000,Fast Road ,,
SD1Web,,34,63,81,26,277/287,111,60,0.55,-4.0,1500-5000 ,Torque,,
Kent,H224,36,78,85,39,294/304,112,75,.494/.520,1.5,2000 - 5500,Road Rally ,Slight loss of flexibility.,
SD1Web,,37,64,80,31,281/291,109,68,0.55,-3.0,1500-5000 ,T&P,,
Kent,H234,38,80,87,41,298/308,112,79,.520 /.542,1.5,,Rally ,Poor low end but improves mid and top end power. ,
SD1Web,,40,70,80,40,290/300,108,80,0.55,0.0,2000-5500 ,Power,,
SD1Web,,40,66,83,33,286/296,109,73,0.55,-3.5,2000-5500 ,P&T,,
Piper,V8BP285,41,75,75,41,276/276,107,82,0.420/0.420,0.0,1500 - 6000,Fast Road ,Ultimate road cam. +30hp,
JE,JE102,43,79,79,43,302/302,108,86,0.500,0.0,3000 - 6500,Rally ,Good high end power. Peak torque 5000 rpm ,
SD1Web,,43.25,76.75,81.75,43.25,300/305,108,86.5,0.55,0.0,2500-6000,Power,,
Piper,HR285,44,72,72,44,296/296,104,88,0.439,0.0,2000 - 6500,Fast Road ,Ultimate road cam. Tractable but slightly lumpy tickover. ,
Kent,GPA,44,76,76,44,300/300,106,88,0.390,0.0,,Rally ,"Same valve lift as standard engine (.390"") ",
Oselli,RV8500,46,82,82,46,308/308,108,92,0.542,0.0,4000 - 7000,Race ,Ultimate hyd. camshaft.,


It was an entry from a poster on Triumph TR8/TR7/Rover V8 Forum :: Index (http://www.thewedgeshopforum.com/)
However my comments stand that you cannot really measure it at the rocker unless you inserted a solid lifter, and were sure the rocker ratio is correct. You would soon find out the .390 is at the valve.
Regards Philip A

[400HPONGAS]

Piper,HR285,44,72,72,44,296/296,104,88,0.439,0.0,2000 - 6500,Fast Road ,Ultimate road cam. Tractable but slightly lumpy tickover.

Now thats more like it , stick this one it at 6 degrees advanced , that will pull the power back 1500 RPM , so its suitable to luh around in a 2.5 ton car !!

Alas , all these cams really wont do anything much without Headwork .Me mate ports even the early heads out to over 300hp Flow potential .
Yep 200kw out of 3.5 , streetable engine . Easily done , but not cheap !!

[blackbuttdisco]

I had a look at the Triumph/Roverwebsite that was on Phillpas post. Yank bloke claimd Rover "forgot " to put a hole in the distributor drive gear for the oil to get out. Now when you consider how many Rover V8s are happily motoring almost everywhere in the world, does this bloke know what he is talking about. He appears to claim he knows more than a very big engineering and development company, or is he just another septic tank?

[PhilipA]

I haven't read the bit you are talking about , but maybe he was referring to the fact that the major tuners recommend that a hole be drilled in the front face of the block right in the V of the valley, so that oil draining from the heads runs onto the cam chain and distributor drive.
This is a well documented mod in UK and recommended in both the tuning books I have read and apparently increases the life of the chain and gear.
Regards Philip A

[bee utey]

I had a look at the Triumph/Roverwebsite that was on Phillpas post. Yank bloke claimd Rover "forgot " to put a hole in the distributor drive gear for the oil to get out. Now when you consider how many Rover V8s are happily motoring almost everywhere in the world, does this bloke know what he is talking about. He appears to claim he knows more than a very big engineering and development company, or is he just another septic tank?
On carby engines the "missing" hole is a notch in the fuel pump cam's keyway, I assume the efi engine has a notch in its spacer too. The oil feed is via a hole in the cam from the front journal. I have seen drive gear failure twice from incorrectly fitted spacers.

[PhilipA]

No, the oil feed to the distributor drive is via the space between the keyway and the spacer on the cam nose and then via a groove in the distributor drive, which I guess overlaps the spacer so lets the oil out onto the drive.

I have just read the manual and realise that I have put the distributor drive sprocket in back to front and now I have to dismantle it and correct the error. Damn,Damn, damn!!!!

So this thread was useful to me.

[PhilipA]

34302

Here is a pdf of the page.
Regards Philip A

[shaunp]

If you want a new cam Ring Dean Tighe and tell him what you want it to do he will have a grind.

do a google for Tighe cams brisbane.

[bee utey]

No, the oil feed to the distributor drive is via the space between the keyway and the spacer on the cam nose and then via a groove in the distributor drive, which I guess overlaps the spacer so lets the oil out onto the drive.

I have just read the manual and realise that I have put the distributor drive sprocket in back to front and now I have to dismantle it and correct the error. Damn,Damn, damn!!!!

So this thread was useful to me.



Correct, the keyway is the channel for the oil after it has passed through the hole in the cam's thrust collar, the pic is not that clear but the hole is just above the keyway.

http://www.aulro.com/afvb/attachment.php?attachmentid=34305&stc=1&d=1300237442

I have just confirmed that the carby fuel pump cam has the notch, and the 3.5EFI dissy drive gear has an annular groove to spray oil from behind the gear. The inner ring of the groove is a few thou proud of the rest of the gear, leaving a gap all the way around. Theoretically it should work either way around, the washer is flat and would leave a similar gap. Actually the washer is a tad too small so the oil feed would be bigger. Would it starve the front cam journal of pressure? Possibly not. Certainly it would spray oil around the timing case.

So critical ignorance might lead you to use an EFI spacer with a carby drive gear, leaving you with a "missing" hole. Interesting, the things you find when you look.

[PhilipA]

So what do you reckon?
Leave it as is? or pull the front apart again to flip the drive gear.

My thought is that the oil may not splash back towards the chain which I believe is the intention of having the groove on the back of the gear.

I should have read the manual when I was unsure which way around. I just checked whether the gears ran the right way for the dizzy gear and was to tired to think logically whether it was the same either way which it obviously is.


Regards Philip A

[bee utey]

So what do you reckon?
Leave it as is? or pull the front apart again to flip the drive gear.

My thought is that the oil may not splash back towards the chain which I believe is the intention of having the groove on the back of the gear.

I should have read the manual when I was unsure which way around. I just checked whether the gears ran the right way for the dizzy gear and was to tired to think logically whether it was the same either way which it obviously is.


Regards Philip A

The dissy driven gear will spray oil back onto the chain. Either way the notch/groove is 1 to 1.5 inches in front of the chain line. And the oil drainage is towards the bottom sprocket. I would just monitor chain stretch for a while, have a new chain on hand when or if it gets sloppy.

[blackbuttdisco]

Go to TR8/Tr7/Rover forum near the bottom of PhillipA's post and open it. If you go to the discussion section for Rover V8 and open it, then open "Distributor drive gear" and also open "Yep, it was the distributor drive gear". Read these 2 and tell me that this bloke knows more than Rover do.

[bee utey]

EFI drive gear with groove facing spacer, oil feed via keyway, gear thinner outside groove, washer just covers keyway and is slightly smaller in diameter than outer groove dia.

http://www.aulro.com/afvb/attachment.php?attachmentid=34312&stc=1&d=1300248720

[PhilipA]

So I reckon it is OK either way.
There must be a LOT of oil flinging around in there at 1000RPM camshaft speed.
Regards Philip A

[shaunp]

I reckon oil will come past the bearing in anycase. On ford windsor/clevos, its common practise to block the oil gallerys from the mains up to the cam bearings with a grub screw in which you drill a small hole. This is to ensure the crank gets priortiy at high rpm. The result is the cam and timing chain getts less, dosen't bother them, so I can't see why the LR engine would play up. Windsors oil the chain via slot in the back face of the cam sprocket. But the Roller master timing setts dont have this groove, again it seems there is plenty of spray around to lube things. I drill a small hole in the front gallery plug in windsors to spray some oil around the timing cover on engine with a HV pump. I wouldn't worry too much.