Competition Cam Question

[Halfbakediesel]

wanting a cam looking at either helix 2 or 3 or something simular. would like the stage 3 what is the drive ablity like thanks

 

[HeavyHauler]

The Helix 3 is built for maximum horsepower, top-end performance. So you will lose some drivability with the H3 over the H2.



A cam swap makes a very subtle difference in performance - it is not worth the trouble for most people, including a lot of drag racers and pullers.



Looking back, I would say that my cam swap was only worth my time and money for the education gained, not the added performance.

 

[HARNESS]

Do you need to fly cut the pistons with the Helix 3 cam?

 

[FUL POWER]

no you do not need to cut the pistons for the helix 3 cam

 

[HARNESS]

I have been told if you don't fly cut the piston your just wasting your time!

 

[Jetpilot]

I have been told if you don't fly cut the piston your just wasting your time!

Just ain't true... .



Doug

 

[HARNESS]

Wath kind of lift and duration? And what kind of rpm gain can you get.

 

[HARNESS]

What kind of lift,duration ,rpms without fly cuting

 

[Jetpilot]

Lift and duration are kept under wraps..... The Helix 2 is good for idle to 4000 rpm and Helix 3 is from 1500-5000 rpm.

 

[HARNESS]

Who sells the Helix3 and how much.

 

[Rams-n-Hogs]

I have to agree with Heavy Hauler. If I had to do it over again, I probably wouldn't. My money would have been better spent elsewhere.

 

[HeavyHauler]

Yep - no fly-cutting pistons needed with Don's cams.



As for where to get one - I would get it touch with Jetpilot (Doug) at PDW. He has handled my latest diesel fixes, and I really like doing business with him.



One more thing on the F1 cams - you'll need the heavy duty valve springs if you run the H3, and it's strongly recommended that you get them with the H2. Changing them is no problem, but it almost doubles the cost of the project.

 

[WUnderwood]

I have read that if you plan to run a Helix 3 cam( from Formula 1 diesel), on a common rail, you need some serious fuel (big P-pump or CP3) and some serious RPM's. I dont think you could spool it on the street



also, heavy duty springs are a good idea



hope this helps

 

[Graphic man]

What kind of lift,duration ,

A Dial indicator and a degree wheel will tell ya

 

[wildmanben]

so it sounds like you guys arent liking the cams? I was thinking about getting one, but maybe not?

 

[ESorensen]

CAms

I was kinda thinking of doing the same thing. I would like to get a cam for the reduction in EGT not for the power gains. Is this still doable? I have heard as much as 200* F reduction with a #2 cam. Is this true?

 

[Jetpilot]

so it sounds like you guys arent liking the cams? I was thinking about getting one, but maybe not?

Well the guys we have put cams in their trucks are all happy. A cam is NOT like injectors or a box, it is a subtle change. It can make a big difference in the power band of a engine though. Take an F1 H2 cam, the truck makes power over about a 500-600 wider rpm range. This equates into moving fatser sooner. The H3 cam helped our truck to breath and make power to right at 4000 rpm, (the OEM cam dropped off around 3300.



Cams are part of a "package" and are a nice addition. But they should be installed with the proper expectations. Egt control, spoolup, power range can all be improved with the proper cam.



Doug Smith

 

[COMP461]

Cams are about airflow, and in a diesel airflow is the most significant way to achieve safe reliable power. Fuel is the easy part.

Diesels performance cams do not exhibit the tradeoff normally associated with performance cams in a gasoline engine. The diesel performance profiles being significantly shorter then their gas counterparts, thereby avoiding the reversion problems. Reversion is caused but big duration grinds that have overlap, “both valves open at the same time “ .

Camshaft in diesel performance applications tend to beef up the numbers on both side of peak horsepower and more noticeable higher in the dyno test. These gains are felt in seat of pants acceleration. Now to the benefits of proper camshaft selection, you can make big power gains by using cam selection to help drive bigger charger, what I term “thumping the chargers”. This action is achieved, by harnessing the wasted power left after the piston has moved down the bore to a point when the retreating piston receives no gain from the expanding gases still burning in the cylinder. Cam timing can be such that the exhaust valve earlier, achieving what is called “blowdown “this dramatic increase in exhaust pressure pulse will drive a bigger A/R on you turbo , and use pulse and not just drive pressure to spin the turbo. This bigger turbine selection results in less total back pressure and thereby less heat is retained in the exhaust side of the engine.



There is so much more too this balancing act then grabbing the popular cam and screwing it in, asking for results, it’s a combination of careful selection of complimenting parts and spending time to make it all work in harmony

 

[nascar mark]

Cams are about airflow, and in a diesel airflow is the most significant way to achieve safe reliable power. Fuel is the easy part.

Diesels performance cams do not exhibit the tradeoff normally associated with performance cams in a gasoline engine. The diesel performance profiles being significantly shorter then their gas counterparts, thereby avoiding the reversion problems. Reversion is caused but big duration grinds that have overlap, “both valves open at the same time “ .

Camshaft in diesel performance applications tend to beef up the numbers on both side of peak horsepower and more noticeable higher in the dyno test. These gains are felt in seat of pants acceleration. Now to the benefits of proper camshaft selection, you can make big power gains by using cam selection to help drive bigger charger, what I term “thumping the chargers”. This action is achieved, by harnessing the wasted power left after the piston has moved down the bore to a point when the retreating piston receives no gain from the expanding gases still burning in the cylinder. Cam timing can be such that the exhaust valve earlier, achieving what is called “blowdown “this dramatic increase in exhaust pressure pulse will drive a bigger A/R on you turbo , and use pulse and not just drive pressure to spin the turbo. This bigger turbine selection results in less total back pressure and thereby less heat is retained in the exhaust side of the engine.



There is so much more too this balancing act then grabbing the popular cam and screwing it in, asking for results, it’s a combination of careful selection of complimenting parts and spending time to make it all work in harmony

No doubt some one at Banks is now posting for Comp.

 

[Jim Fulmer]

Cam timing can be such that the exhaust valve earlier, achieving what is called “blowdown “this dramatic increase in exhaust pressure pulse will drive a bigger A/R on you turbo , and use pulse and not just drive pressure to spin the turbo. This bigger turbine selection results in less total back pressure and thereby less heat is retained in the exhaust side of the engine.

I'm learning this the hard way! I'll soon change to my third cam to try and make this better, below 2200 (2000 rpm is on the edge) After that point boost and response is perfect.



Jim