Ok, I have a JBP turbo cam Im planning on putting in (either this spring into the mostly stock block, or when I finish my other motor build).. I've been looking at the specs that I have for this cam versus my stock one, and I was wondering if someone could shed a little light on what it all means (it still a lil foregin to me).

JBP Turbo Cam
Duration:
.050*

Valve Lift:
Intake 195*, 456
Exhaust 192*, 440


Stock Cam
Lift:
Intake Exhaust
@lobe @lobe
.263 .263
Intake Exhaust
@valve @valve
.394 .394

Duration
Intake Exhaust
262° 262°

Valve overlap: 41°
Intake Exhaust
@ .050" @ .050"
185° 185°

Intake Centerline - Exhaust Centerline
116° - 110°

.050" Valve Timing:

Intake Opens - Intake Closes - Exhaust Opens - Exhaust Closes
19°ATC - 24°ABC - 22°BBC - 17°BTC

Lash:
Intake Exhaust
Hyd. Hyd.




Edited 2 time(s). Last edited Wednesday, January 23, 2008 9:59 AM

I'm no cam pro, but the turbo cam has higher lift, for ultimately more head flow, and less overlap, so less blowby of pressurized air - just what you want in a turbocharged system. Please PLEASE be sure to post the results after the install!

Ok, that makes sense...

I will definitely be keeping updates when I change things... Right now Im on a stock block and I was planning on saving the cam until I build my spare block... but Im putting in new lifters with the LTI spring conversion in the Spring as soon as it warms up ( I THINK I have a collapsing lifter)... So I'm thinking that because I have it down, I might as well go the extra steps and put the cam in as well. Although Im just wondering how the stock pistons/rings/rods/crank will take to it. Hence why I'm still undecided. I wont be upping the boost until I put the block in with full forged internals, but that wont be for another year or two... My BF's SS/SC is going under the knife this year as well as the fact that I'm so far really please with the stock block so im not in a big rush.

Im just sick of seeing the cam sit in my living room, I've had it about a year and its not doing much as a decoration

Ok this may be a newbie question but w/e...

If the cam has higher lift will that give a greater change of the valve springs binding?


Right now im using stock rockers with stainless valves & JBP valve springs, with the way the valve seats were machined, im unable to use higher lift rockers with this spring/valve set up. (When Crane gold series rockers were used on this head, it caused the push rods to come out of their seat in the rocker). I was given the engine like this, and fixed it and with stock rockers it runs great.

I wasn't sure how this would if at all interfere, so figured I'd ask.

To test for interference, you would want to rotate the crank about two revolutions. That will do two things. First, if there is something prevening your from turning it past a certain point, then a valve may be hitting the piston. That will be one check. Rotating the crank will also tell you how much the coils will bind at their lowest point. You obviously want to do this before your start the motor.

I've also been suggested that this be done with no head gasket. What this will do is ever so slightly increase the lift on the valves. That way, if it doesn't bind with no head gasket, then you're assured it won't bind with the head gasket in. When the head gasket is installed, it has a certain thickness, and that thickness puts the head further away from the cam, so the push rods don't come up as much.

If everything checks out without the head gasket, remove the head, put the head gasket on, and finish assembling. Also, you don't need to put all the rockers in when you do this test, just once set of intake and exhaust. then see how much each binds, and go from there. I have the JBP cam already install, and I can see when i rotate the cam, that the intake opens more than the exhaust.

Also, as far as the cam specs go, It looks like the stock lift for the intake/exhaust is .394/.394 inches. The JBP specs are .456/.440 (assuming stock rocker rollers)

So, the valve lift is more, but if you run through the test above, and double check the clearances, you shouldn't have a problem.

Im bringing this back from the dead because the information on the JBO turbo cam is incorrect.... the duration is measured @ .050* (i misread what they had on the website)... however they do not state the ACTUAL duration so I'll have to find that out...

JBP.... whoops

"Actual" duration is typically measured at .002, or .004 inches of lift, although I've seen figures quoted for .001" lift.

-->Slow

Jazer {AzulKav} Turbo Chica wrote:Im bringing this back from the dead because the information on the JBO turbo cam is incorrect.... the duration is measured @ .050* (i misread what they had on the website)... however they do not state the ACTUAL duration so I'll have to find that out...

The cam timing you listed is also at .050". You can use that for comparison. It looks like you have about 10° more on the intake, and 7° more on the exhaust.



fortune cookie say: better a delay than a disaster

I guess im confused...

Both are measured at .050, however only the stock cam shows what it read at .050, the JBP turbo cam states nothing of what it read at .050 as far as Duration.

Here is a direct c& p off their site:

Forced Induction 2.2L LN2 OHV

Duration @ .050*, Valve Lift INTAKE 195*, 456 EXHAUST 192*, 440

Translated from the poor description:

Duration @ .050*:
INT - 195*
EXH - 192*

Valve Lift:
INT - 0.456"
EXH - 0.440"




fortune cookie say: better a delay than a disaster

ok that makes a bit more sense, thanks so less duration, more lift.

Jazer {AzulKav} Turbo Chica wrote:ok that makes a bit more sense, thanks so less duration, more lift.

No...more of both. The stock cam is 185/185.



fortune cookie say: better a delay than a disaster

oh yea whoops i was looking at the wrong thing

I haven't really put too much into finding the specs for the 2200, but Jess, those numbers are completely different from what I have heard previously. I definitely not saying your wrong, but more than likely yours are correct. That's more detailed, specific information than I have received elsewhere.

Now I have to go through and rethink the cam profiles for the 2200! With what I've played with so far, the lobe centers hold alot of potential, especially for N/A motors! Even more potential than the 2.2L cam, which is a little better suited to boosted applications.

I am getting a used 2.2L block and I need to borrow a 2200 cam, so I can verify the specs on both the 2.2L cam and the 2200 cam. I'll also be checking the cam timing notch location, so that issue can be settled.

Up until now, I've relied on specs Crane gave me as far as the C/Ls go, but they've given two different specs on that, what they gave me (109* Int Center Line, 114* Lobe Separation) and what they gave someone else (109* Int C/L, 113* L/S). I've been tailoring my cam profiles by the specs they gave me from my cam. The lift and duration specs from other sources.

Jack, I can provide you with a loaner 2200 cam... I plan on putting my focus on the head and the rest of the valvetrain for the time being, and that'll probably take me a couple of months at the minimum, so I won't need the cam any time soon. Just gotta get the motor on the stand and break it down.

On a side note, finally got pics of the cut up head, just need to organize it into a coherent article and post it up. 56K DEATH lol.




Arrival Blue 04 LS Sport
Eco
Turbo
Megasquirt
'Nuff said