The Truth on Cam Advertised Duration, Etc.

[Archer Fabrications]

I posted the 276/276 cam card that dustin gave me for the review i did. I dont think they are a clone of the kelfords, but they are on par. As per advertised specs, kels, i dont know if you were told to keep them a secret or not but i wasn't told any such thing and am not bound by any such agreement, so it's out there for people to see as per requested in my review. (Which is incomplete)
http://www.dsmtuners.com/forums/art...399-new-design-stage-3-bc276-276-testing.html

 

[spoolin ddub]

I posted the 276/276 cam card that dustin gave me for the review i did. I dont think they are a clone of the kelfords, but they are on par. As per advertised specs, kels, i dont know if you were told to keep them a secret or not but i wasn't told any such thing and am not bound by any such agreement, so it's out there for people to see as per requested in my review. (Which is incomplete)
http://www.dsmtuners.com/forums/art...399-new-design-stage-3-bc276-276-testing.html

Those aren't the cams specs I was given this morning. He asked me to keep the info confidential until they are released and they aren't finalized.

 

[Archer Fabrications]

I was given these in december

Dustin asked me to post this, since hes a newbie still (, get those posts dustin!)

"What we did with the new BC 276 cam is we took our older profile and
totally redesigned it. We shortened the advertised duration from 280 down to 276.

On the [email protected] we increased the intake 2 degrees to 220 at .050 and also increased the EX to match.

On the lift we increased from 10.71mm on the intake
to 11.07mm and on the exhaust we increased the lift from 10.6mm to 11.07mm.

The shorter advertised duration changes the ramp speed and acceleration and the results were very positive.

Thank you,

Dustin Spencer"

 

[spoolin ddub]

I was given these in december

Dustin asked me to post this, since hes a newbie still (, get those posts dustin!)

"What we did with the new BC 276 cam is we took our older profile and
totally redesigned it. We shortened the advertised duration from 280 down to
276. On the duration at .050" we shortened the intake 2 degrees and kept the
same 216 on the exhaust. On the lift we increased from 10.71mm on the intake
to 11.07mm and on the exhaust we increased the lift from 10.6mm to 11.07mm.
The shorter advertised duration changes the ramp speed and acceleration
and the results were very positive.

Thank you,

Dustin Spencer"

I'm just say I don't think what they gave you was set in stone.

 

[Archer Fabrications]

Spoolin, dustin told me you got the wrong cam card.
I'll post the correct one.

Heres the cam card info he provided me.

STAGE 3 BRIAN CROWER 276/276 CAMSHAFT

Intake
Advertised duration 276
Duration @ .050: 220
Lobe lift .252"
Valve lift .436"

Intake centerline 106

Exhaust
Advertised duration 276
Duration @ .050: 220
Lobe lift .252"
Valve lift .436"

Exhaust centerline 114

Intake opening 4 BTDC
Intake closing 36 ADBC
Exhaust opening 44 BBDC
Exhaust closing 4 BTDC

 

[spoolin ddub]

Spoolin, dustin told me you got the wrong cam card.
I'll post the correct one.

Heres the cam card info he provided me.

STAGE 3 BRIAN CROWER 276/276 CAMSHAFT

Intake
Advertised duration 276
Duration @ .050: 220
Lobe lift .252"
Valve lift .436"

Intake centerline 106

Exhaust
Advertised duration 276
Duration @ .050: 220
Lobe lift .252"
Valve lift .436"

Intake centerline 114

Intake opening 4 BTDC
Intake closing 36 ADBC
Exhaust opening 44 BBDC
Exhaust closing 4 BTDC

he just apologized and verified correct info

 

[Archer Fabrications]

excellent

 

[pacn91]

This is just a typo, im sure, but how is the intake cam going to have occupy a centerline of 106 and 114? Im assuming that the intake is at 106 and the exhaust is at 114. I noticed that something else is missing, since we kind of have to bench race to make light of a cam card. Of course, if you know what you are doing then LSA can be easily figured out ...LSA @ 110. Im just wondering how important is it, for you guys, to know LSA as well....honest question. When I look at cam cards, being that im more ignorant than many of you experienced fellas, I like to know everything that I can. I have to agree that there is more to the cam science than just the lift and duration. Also, for effort of approaching a less violent valve train i would opt for the less lift more duration cam. Of course, for racing/competition, ideally we should bench flow our heads and then custom grind a set of cams. If we cant get customs, then obviously the most appropriate "shelf cams" are the next best thing. Its all about setup, or purpose, for those of us who dont know. On another note, I do like the specs for the new 276 cam. Should be a nice higher rpm cam for a 2.0. Also, what kind of powerband? Just guessing, im thinking 4k-8k neighborhood.

 

[Archer Fabrications]

Yeah sorry exhaust centerline is 114, I'll fix that

 

[spoolin ddub]

And for those who just are BC ass burnt and do not believe the BC 276 info. I believe what they are saying. They have info out on the new BC 284/280 cam. It was put on their website last year. Keltalon also posted it in a thread last year. Look at it compared to the FP 5R cam. The BC is just slightly smaller. But it is still large enough to be in the same category!!

BC 284/280
http://www.briancrower.com/makes/mitsubishi/cam_card/bc_0103-2.pdf

FP 5R
http://store.forcedperformance.net/merchant2/graphics/info/camcards/dsmfp5r.pdf


Please do not get my motive of wanting to post accurate info confused with being a fan boi. I have no relationship or agreement with BC.

 

[keltalon]

And for those who just are BC ass burnt. I believe what they are saying. They have info out on the new BC 284/280 cam. It was put on their website last year. Keltalon also posted it in a thread last year. Look at it compared to the FP 5R cam. The BC is just slightly smaller. But it is large enough to be in the same category!!

BC 284/280
http://www.briancrower.com/makes/mitsubishi/cam_card/bc_0103-2.pdf

FP 5R
http://store.forcedperformance.net/merchant2/graphics/info/camcards/dsmfp5r.pdf

I have a set of these 284/280 sitting here in the shop. I took them out because the cyclone manifold was just not matched with them. They idle great and the quick third gear pull on my YouTube channel was with these installed. I will be upgrading my setup to a jmf street manifold and the bc 276s but not before another attempt to up the cyclone numbers. From my mad scientists stand point this will be my next big thing for me aside from the cyclone and bc 272s. Still waiting on jmf street manifold and map t3 exhaust manifold to be completed.

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[Archer Fabrications]

And for those who just are BC ass burnt and do not believe the BC 276 info. I believe what they are saying. They have info out on the new BC 284/280 cam. It was put on their website last year. Keltalon also posted it in a thread last year. Look at it compared to the FP 5R cam. The BC is just slightly smaller. But it is still large enough to be in the same category!!



BC 284/280

http://www.briancrower.com/makes/mitsubishi/cam_card/bc_0103-2.pdf



FP 5R

http://store.forcedperformance.net/merchant2/graphics/info/camcards/dsmfp5r.pdf





Please do not get my motive of wanting to post accurate info confused with being a fan boi. I have no relationship or agreement with BC.

I'm not a fanboy either, the only agreement i have is to review the parts i was given and give my personal experience with the products GOOD OR BAD! And hop on the dyno with the new parts. I won't heaitate to tell the truth if there is something i dont like about the product. But so far just from examining everything. BC has not disappointed me yet


Kels, your not even t3 yet?

 

[LandSpeed-DSM]

Turbo cars don't inherently perform better with minimal/no overlap. This is dated information that goes back to the 70s when we had inefficient turbines in ancient scroll cases and turbochargers were still largely the domain of "medium-speed" diesel engines in trucks and equipment.

So let's clear this up if we are truly aiming to have a discussion.

The overlap region is very important in how the engine performs, and while there are many things that go into how the final decision is made on how big or small to make that part of the cycle, the main determinant is the pressure differential between intake and exhaust. It doesn't matter if it's a "street build" or not.

I have been a proponent of this approach now since 2008 when I started experimenting with this hypothesis, and it's why you will read me discussing Drive:Boost ratios so often on this forum still, now 6 years later.

Because it's almost entirely overlooked yet crucial to performance across the board.

If you are running a T25 on a stock manifold with a stock O2 housing and a full length 2.5" Cat'd exhaust - then the statement:

turbo cars perform better with less overlap

Has some merit.. but it's because you will easily have around ~2.5 times as much pressure (or more) in the exhaust manifold as you do in the intake causing reversion, at the same time you will have your normal cylinder to cylinder contamination from the undivided manifold/turbine scroll case.. just magnified by the even greater pressure differential.

A larger, more efficient turbine and housing, especially when combined with a fully divided hotside and very low post-turbine restriction will thrive on adding in overlap either through the cam grind or through adjustable gears with many aftermarket cams in the case of a DOHC like our motors.

The closer you get to 1:1 (I see as low as 0.8:1 Drive:Boost) .. you cam it more like an N/A or even an S/C engine. But you can use a fairly mild cam in terms of ramp rates and lift, opting for more duration if you need to breathe at high rpm.

Other proponents of this concept? Just some nobodies.. like Kenny Duttweiler and Billy Godbold (Comp Cams Head Camshaft Designer)

Godbold, ca. 2010
Cams for Turbocharged Engines - Hot Rod Magazine

Duttweiler, ca. 2011
Turbo Camshaft Guide - How to Select the Right Cam for Your Turbocharged Engine - Car Craft Magazine

Don't forget these gasses have inertia, even with high Drive:Boost ratios you still want to take advantage of the overlap and just shutting the exhaust valve early isn't necessarily helping. You are then constantly keeping extra exhaust in the cylinder and likely more than you have to which not only hurts VE, but will leave you more knock prone.

 

[keltalon]

Turbo cars don't inherently perform better with minimal/no overlap. This is dated information that goes back to the 70s when we had inefficient turbines in ancient scroll cases and turbochargers were still largely the domain of "medium-speed" diesel engines in trucks and equipment.

So let's clear this up if we are truly aiming to have a discussion.

The overlap region is very important in how the engine performs, and while there are many things that go into how the final decision is made on how big or small to make that part of the cycle, the main determinant is the pressure differential between intake and exhaust. It doesn't matter if it's a "street build" or not.

I have been a proponent of this approach now since 2008 when I started experimenting with this hypothesis, and it's why you will read me discussing Drive:Boost ratios so often on this forum still, now 6 years later.

Because it's almost entirely overlooked yet crucial to performance across the board.

If you are running a T25 on a stock manifold with a stock O2 housing and a full length 2.5" Cat'd exhaust - then the statement:


Has some merit.. but it's because you will easily have around ~2.5 times as much pressure (or more) in the exhaust manifold as you do in the intake causing reversion, at the same time you will have your normal cylinder to cylinder contamination from the undivided manifold/turbine scroll case.. just magnified by the even greater pressure differential.

A larger, more efficient turbine and housing, especially when combined with a fully divided hotside and very low post-turbine restriction will thrive on adding in overlap either through the cam grind or through adjustable gears with many aftermarket cams in the case of a DOHC like our motors.

The closer you get to 1:1 (I see as low as 0.8:1 Drive:Boost) .. you cam it more like an N/A or even an S/C engine. But you can use a fairly mild cam in terms of ramp rates and lift, opting for more duration if you need to breathe at high rpm.

Other proponents of this concept? Just some nobodies.. like Kenny Duttweiler and Billy Godbold (Comp Cams Head Camshaft Designer)

Godbold, ca. 2010
Cams for Turbocharged Engines - Hot Rod Magazine

Duttweiler, ca. 2011
Turbo Camshaft Guide - How to Select the Right Cam for Your Turbocharged Engine - Car Craft Magazine

Mine performed better with minimum overlap and a cyclone dyno record , and dynos to back it up i love saying that it feels good! LandSpeed-DSM it's plain and clear you are trolling this site and doing a good job at trying to ruin every thread started by the brothers. your anti - tiger comment is really manifesting itself clearly. Can't you just let us enjoy sharing information that's proven with each other? We never try to contaminate your threads.

 

[keltalon]

Dubb maybe your thread will survive the LandSpeed-DSM virus and in that way some cam results will get posted here.

 

[spoolin ddub]

The thread was going good. Come on y'all. Don't start this fighting shit .

 

[LandSpeed-DSM]

Mine performed better with minimum overlap and a cyclone dyno record , and dynos to back it up i love saying that it feels good! LandSpeed-DSM it's plain and clear you are trolling this site and doing a good job at trying to ruin every thread started by the brothers. your anti - tiger comment is really manifesting itself clearly. Can't you just let us enjoy sharing information that's proven with each other? We never try to contaminate your threads.

How about you deal with the content, for once.

If you have a high Drive:Boost ratio, then it would follow that you would see gains from decreasing the overlap region.. which is entirely consistent with what I am telling you.

So, you posted a link to some dude on a Supra Forum.. I read it and it's basically the same as any cut/paste on cam basics you will find on most car forums.

How about you review the articles from leaders in the field and keep an open mind.

.
.
.

And.. Race-baiting again, really? Is that just your "go to" when you can't deal with technical information?

FYI - No one cares about your obscure "record." Bringing it up at every opportunity is pretty sad.

The thread was going good. Don't start this fighting shit .

It can still go well if we act like adults. Review my post and the accompanying articles, it's entirely relevant.

 

[keltalon]

The thread was going good. Come on y'all. Don't start this fighting shit .

Don't worry dubb i will permanently block him. Lol Carry on!

 

[LandSpeed-DSM]

Don't worry dubb i will permanently block him. Lol Carry on!

Yea, that's a healthy approach to new information.

Now let's stick to the topic, shall we?

 

[Archer Fabrications]

Does someone with kelfords and their proper cam card have the specs they can post up for compairison? The ones on websites are slightly different at degree when they advertise the cams profile.

Example. Bc measures at .050 lift and kelford at 1mm? Unless I'm a fool and .050" is 1mm

 

[LandSpeed-DSM]

Does someone with kelfords and their proper cam card have the specs they can post up for compairison? The ones on websites are slightly different at degree when they advertise the cams profile.

Example. Bc measures at .050 lift and kelford at 1mm? Unless I'm a fool and .050" is 1mm

1mm = ~0.040"

Their cards use 1mm as well.

I've seen people try to estimate the duration from one to the other, but you'd really have to measure it.

 

[Archer Fabrications]

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[keltalon]

Does someone with kelfords and their proper cam card have the specs they can post up for compairison? The ones on websites are slightly different at degree when they advertise the cams profile.

Example. Bc measures at .050 lift and kelford at 1mm? Unless I'm a fool and .050" is 1mm

No 1mm is .040 lift

 

[spoolin ddub]

Does someone with kelfords and their proper cam card have the specs they can post up for compairison? The ones on websites are slightly different at degree when they advertise the cams profile.

Example. Bc measures at .050 lift and kelford at 1mm? Unless I'm a fool and .050" is 1mm

You cant compare the measurments of duration @.050 to 1.0mm/.040. Dsport put every cam it tested real numbers @ 1.0mm and @ .050. That's why its more accurate in a cam analyzer. Its better to have measurements directly at the cam with no added variables vs what companies post. Which is specs from the valve.

 

[Archer Fabrications]

Thats why i asked if someone has the actual specs at one or the other from someone that has thrum .050 Or 1mm

i guess i didn't read the article from dsport