Drop in Cam gains for Twinned 12V??

Red Stroke

Red Stroke

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Aug 2, 2006
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What HP gains have been seen with a drop in Hamilton Diesel cam in a twinned 12V over a stock cam?
 
depending on how overfueled the truck is between 28-40 hp. With our larger 12v cams we have seen up to 76hp at the higher rpms. Flycut is necessary, and driveability is compromised slightly.

Zach Hamilton
 
Yes bottom end suffers. Spoolup is probably 400-600 later. The Opening and closing events are all optimized for high rpm power not efficient street driving. The main way we pick up the extra power is that we leave the intake open up to 40 degrees after bottom dead center as opposed to around 20 degrees on a street cam. At low rpm, with the big cam, the intake is open so long the piston,on its way up, actually pushes some of the air back into the intake runner. This makes it a dog on the bottom end. About 3000 rpm and up a little bit of magic happens. THe intake is open for such a short amount of time that the cylinder is not getting the maximum amount of air it needs with a street cam. Now put a monster duration intake in there and you can still ram a bunch of air into the cylinder even though the piston is traveling up. There is no linear power curve, the engine will "turn on" like a switch between 3000-3500 rpm. This works great on p-pump trucks for sled pulling, for vp and cr trucks this is not an option though. With a cam like this there is considerably more overlap and it is important, scratch that, a MUST to keep drive pressures in check.
 
Well my driveability issues are:

10 mpg no matter how it is drove. (13mm pump)
Being decompressed, and no heaters starts like crap below 50 deg (big Scheids cam)

I am going to throw in my spare motor with my 913 set at 650cc (did 1312hp with it).

I dynoed 796 hp with my current not very streetable setup and I think I can do the same with my other motor, just trying to decide if it would be worth throwing in a drop in cam? What lifters do you recommend? Does your cam have the bolt on gear retainer?

Thanks
Adam
 
Our cams can be ordered with the bolt on retainer. If you are running over 4500rpm I suggest getting the front of the cam radiused to relieve stress risers that can potentially be a source of fracture at high RPM. Our cast billets are $599 in bigstick fashion(181/210), and $799 for a custom one off cam
If you want a custom cam done I really need to know the valve face depth from the head deck, flow numbers on the head, amount of flycut, desired rpm range, and if you know it the ratio of boost to drive pressure. I can work with part or all of this but the more info I get, the better cam you get for your application. As far as lifters are concerned, my personal favorite is the 24v 98-02 they are larger around than the 12v but they don't weigh much more. The cr's have much more surface area but also weigh alot more than either the 12v or the 24v. Sometimes they can also have clearance issues with fuel pump eccentrics and journals. I use stock 24v and get Geoff to resurface them with a slight radius which is better suited for cams with aggressive ramp rates.

Zach
 
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For now I am just looking to throw a drop in upgrade cam in my spare motor. I would always use a bolt on retainer after seeing those gears walk of when you are turning a big pump hard.

(181/210) you talking duration?

What is the cost of a drop in with lifters? You can PM if needed.

Thanks Adam
 
181/210 is the duration @.050" lift. .280"/.307"is the lift. This can be put on your core for $349 or we can do it on a new cast billet for $599. Any of the lifters are fine to use with this, but my favorite are the 24v 98-02. I don't sell lifters currently but Geoff will regrind yours and put a nice crown on them for $8 a piece. On a twinned 12v I would say you will make between 30-40 extra hp with one of these cams
 
Hamilton Cams said:
Yes bottom end suffers. Spoolup is probably 400-600 later. The Opening and closing events are all optimized for high rpm power not efficient street driving. The main way we pick up the extra power is that we leave the intake open up to 40 degrees after bottom dead center as opposed to around 20 degrees on a street cam. At low rpm, with the big cam, the intake is open so long the piston,on its way up, actually pushes some of the air back into the intake runner. This makes it a dog on the bottom end. About 3000 rpm and up a little bit of magic happens. THe intake is open for such a short amount of time that the cylinder is not getting the maximum amount of air it needs with a street cam. Now put a monster duration intake in there and you can still ram a bunch of air into the cylinder even though the piston is traveling up. There is no linear power curve, the engine will "turn on" like a switch between 3000-3500 rpm. This works great on p-pump trucks for sled pulling, for vp and cr trucks this is not an option though. With a cam like this there is considerably more overlap and it is important, scratch that, a MUST to keep drive pressures in check.
Click to expand...



omg!
 
Fletcher, I find It quite interesting that you have time to comment on someone else's thread when you haven't replied back to a thread about your company's cams. Your company has many people that stand behind your product but you can't anwser the phone or call potential customers back. It's just my opinion that you may gain more by not putting your comments on other companies threads and just answering your phone or returning calls.
 
92fordcummins said:
Fletcher, I find It quite interesting that you have time to comment on someone else's thread when you haven't replied back to a thread about your company's cams. Your company has many people that stand behind your product but you can't anwser the phone or call potential customers back. It's just my opinion that you may gain more by not putting your comments on other companies threads and just answering your phone or returning calls.
Click to expand...

Thats why when I buy a new cam with bolt-on retainer it will be a Hamilton Cam. He helped me a lot with a camshaft that I had for a long time with no information on it and and spec'd it out for me. He also gave me a lot of good info about his camshafts and made me feel confident in his products. If I had the cash at the time I did my KDP I would have installed one of his cams instead of the PDR that I already had. I plan on buying one of his cams in the future for sure, Zach is bad ass to do business with and is extremely helpful!
 
Hello? Do you two think that I have one of your cams? I have not had anybody offer one of your cams to the trade up program to date, and I don't go buy other guys cams. Honestly I could care less, I don't count you as competition Fletcher. And what is the OMG! all about? Did you think you were texting or do you have some actual information to post. Don't worry about trying to slam me in my own sub-forum. You are welcome here anytime .................feel free to offer up any comparative data or you can continue to text OMG as much as you want. Bye the way, I'm glad you feel the need to look on my forum for info, I'm sorry I will get around to looking at your sub-forum someday.

Zach
 
92fordcummins said:
Fletcher, I find It quite interesting that you have time to comment on someone else's thread when you haven't replied back to a thread about your company's cams. Your company has many people that stand behind your product but you can't anwser the phone or call potential customers back. It's just my opinion that you may gain more by not putting your comments on other companies threads and just answering your phone or returning calls.
Click to expand...

I would agree.
 
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