Revised N Whiteblock

[lookforjoe]

I have an intake cam from a 2006 N/A motor that I plan to install in mine. Not expecting much of a gain, so I'm not real motivated to replace it. I guess every little bit helps, right??

Not an RNC motor, I hope. They don't fit.

[Volvo5.0]

Not an RNC motor, I hope. They don't fit.

Another reason I'm not too motivated to take it apart. I'm not 100% sure it will fit, and if I ripped it apart and it didn't..... :angry:

[ozzimark]

Measure the width of that bearing. The RN cams are almost exactly 1" between the two flange surfaces.. might be 25mm.

[lookforjoe]

Another reason I'm not too motivated to take it apart. I'm not 100% sure it will fit, and if I ripped it apart and it didn't.....

Just look at the VVT end - this is the difference between the two

RNC on top RN below

[wizzard_al]

Update: Had the chance to check out the cam for the B5234T3 engine, which is the one for '99 and later T5 engines, up to 2003

Intake

920794 duration 258 degrees lift .327", or 8.3 mm B5234T3 engine

So this HPT intake cam has more duration than the cams for the LPT engines

Recap (duration at .050" lift) on '99 and later single VVT engines:

B5234T3 engine HPT

intake 258 degree duration, .327 or 8.3 mm lift #9207943

exhaust 267 degree duration, .364 or 9.2 mm linft # 9207944

B5244T3 LPT

intake 256 degree, .327 or 8.3 mm lift # 9207942

exhaust 267 degree, .362 or 9.2 mm lift #9497822

B5244T LPT

intake 249 degree .328 or 8.3 mm lift # 9207942

exhaust 267 degree .364 or 9.2 mm lift #9207944

Hussein did measurement on dual VVT cams, but you can't compare his duration figures to these, since he measured at .006"

Interestingly, even though the exhaust cam part numbers are different between the B5234T3 and the B5244T3, they all have the same duration and lift, it is only the intake cams that differ in duration.

[lookforjoe]

Bloody Hell. The only reason I had them measured @ .006" is 'cos in the other thread goign back & forth with Mark, Fishey said that was the norm - so they should have been checked @ .050"?? Big difference.

[wizzard_al]

The standard that most, but not all American manufacturers use is .050". Some use different numbers, but this has become a standard, of sorts. I don't know where Fishey got his "norm" and I won't say he is wrong, and he may be using a measurement that is used in Europe, for instance. That means you may see other measurements used, but using something that everyone else uses means you have a basis for comparison. Crane Cams has a series of FAQs that describe measuring cams, etc, and this is what they say about where to measure duration.

http://www.cranecams...view.php?s_id=4

Basically, if you go too much lower on lift for where you start measuring, you are not certain of consistency. I appreciate your measuring at .006", but damn, that dial indicator barely started to move, and I'll bet it is harder to be consistent at that level.

Look at the Crane Cam catalog for several engines nearly the size of the whiteblock:

http://www.cranecams.com/190-191.pdf

for the Ford Duratec DOHC 1.8 - 2.3 engine. Note the duration specs. They show "advertised" duration, and duration at .050" lift. Note that the duration on the high performance cams is almost the same as the Volvo cams I measured at .050" lift. I suspect that your measurement at .006" will produce about the same actual time the valves are off the valve seat as my measurement, just different starting point. Notice the difference in lift, however, in their highest performance engines! nearly .450" or more on some engines, and note that many have way more lift on the intake. (But they are not turbo engines, so may need more lift to fill the cylinder.)

Look at the cams for the Chrysler 2.4 engine in the PT Cruiser:

http://www.cranecams.com/150-151.pdf

Note that once again, they have about the same duration as our turbo cams.

Try other engines of so called high performance small engines:

http://www.cranecams.com/262-263.pdf for Honda

Again, note that the high performance VTEC engines have similar cam duration.

http://www.cranecams.com/268-269.pdf for Mitsubishi EVO engine 4G63

http://www.cranecams.com/282-283.pdf for Toyta 4 cyl, and also 6 cyl 2JZE engine, notable for making massive horsepower!

The best one for comparing a large number of engines is Kelford, from Australia:

http://www.kelfordca...cationGuide.pdf

They gave "advertised duration" then measure same cam at .050" lift, other at 1 mm lift, which is .0394". Check out their duration and lift figures for high performance cams.

What many people don't want to know is that duration is somewhat dependent on engine size. A larger engine will allow you to use longer duration cams, and have a decent street behavior, but still be a strong performer. Smaller engines need to have less duration. Since our engine is a turbo, I suspect that we can get timing that you'd normally see in a larger engine, but that is because we have the turbo; remember, when F1 was first using turbos in competition with NA engines, they had an "equivilency" formula that meant a turbo engine's displacement had to be multiplied by a factor of somewhere around 1.3 or 1.5 to equate it to the size of a NA engine with the same power.

Volvo has a cam with actually decent duration, but the lift is less than some of these very high performance cams. That also makes a huge difference.

When Volvo was in the BTCC with the 850 wagon and then the S40, they had 2,000 cc 5 cyl NA engines, but the best Volvo could produce was 260 HP, while their competitors had 285 hp. So TWR (Tom Walkinshaw Racing) was hired, and they basically took the Volvo head, chopped off the top half of the head, chopped off the face of the intake and added a new side to the head to produce straighter intake ports, and built up a new cam tower set up that allowed them to go from about .300" lift to .825" lift. I am certain that their duration was quite high, but the lift was what did it. (See Racecar Engineering, Volume 19, Aug 2009 for details) Guess I'd say that going from .300" lift to .83" lift is like going from a 2 or 2.5" downpipe, to a 3" downpipe on our turbos. Much more flow. TWR ended up with around 325 hp in these highly modified engines, and the engineer that designed the head and engineered the engine admitted it was due mainly to the head.

[ozzimark]

using something that everyone else uses means you have a basis for comparison.

And that's exactly it. The duration specs we had on the pre-RN turbo and NA cams were measured at 0.006", from what I have been lead to believe.

NA intake cam: 8.45mm lift, 250º

NA exhaust cam: 8.45mm lift, 252.6º

Turbo intake cam: 7.95mm lift, 242º

Turbo exhaust cam: 7.95mm lift, 243.5º

which seems to compare to what I have measured at 0.006" lift on the RN cams I have sitting around:

					   Lift @

PN      Int/Ex  VVT?	   in	   mm	  .006 Dur

6900044 Intake  N	   0.33    8.382   257º

8670354 Intake  Y	   0.314   7.9756  250º

9497822 Exhaust Y	   0.355   9.017   280º

Measuring duration at .050" drops the duration down into the high 100's, low 200's, iirc.

[wizzard_al]

We all agree that consistency in measurement is important for comparison purposes. I just used what is considered one standard. I can measure at .006" if necessary, but I don't think the difference in duration is as much as you say. I did a quick look when it was at .006" lift, and I think the duration changes about 40-50 degrees. I.e., what I showed at 252 degrees duration was probably around 290 degrees at .006". Didn't write it down, so have to do it again.

I notice that your measurement of the 9497822 exhaust cam is different from mine. for lift. I measured lift as total lift, from zero point to maximum lift. Maybe I have to measure it from .006" or .050" and see what it is? That doesn't seem right either, since deducting .049" from the maximum lift would result in .325" or 8.255 mm lift for the exhaust cam, and spec is 9.05 mm. Unless you measured lift from zero, as I did, and then you got a lot closer to Volvo spec than I did. Hmmm, have to see where mypossible errors in measurement are. Getting the dial indicator perfectly vertical could account for some of it, I could lose some accuracy there, and that is the most likely place I had a problem.

[s_moneh]

*edit

[ozzimark]

Unless you measured lift from zero, as I did, and then you got a lot closer to Volvo spec than I did. Hmmm, have to see where mypossible errors in measurement are. Getting the dial indicator perfectly vertical could account for some of it, I could lose some accuracy there, and that is the most likely place I had a problem.

That's exactly what I did. And if your dial indicator is a bit off from vertical, and not right over the CL of the cam, it's gonna throw off the duration numbers you get as well. :unsure:

[wizzard_al]

^^^

Yes, I'm concerned about the dial indicator being exactly where it belongs. I've remeasured, and it isn't exactly the same, but close. Need to figure out a way to get the magnetic base for the dial indicator to stay in place. May have to get another mount for it.

[Kevin.]

So much good info in this thread, this has cleared up a lot of confusion I had about RN motors. Thanks Mark!