Help With Blower Cam.
#11
Guest
Posts: n/a
Re: Help With Blower Cam.
You wont need that much duration. All it will do is raise the powerband to the upper rpm range and not make useable power. . .IE Narrow power band. Lift is to small. Blower like to get the air in and out quick. A lobe with a more aggressive lifter velocity would be a better choice.
Chris
Chris
#12
MarineKinetics
Platinum Member
Re: Help With Blower Cam.
Fastlane40,
Because the 2 cams you listed are Hyd-Flat, do you intend on staying with the flats or converting to roller?
GPM,
What would be the advantage to running the 3299/3295 lobes in this application?
They are the Cheater HR Lift Rule Competition family, which are extremely aggressive competition profiles that are clearly categorized as a "Race Only". They were designed for "lift rule" racing with very fast opening rates and clearly present a durability issue in a marine engine.
Bob
Because the 2 cams you listed are Hyd-Flat, do you intend on staying with the flats or converting to roller?
GPM,
What would be the advantage to running the 3299/3295 lobes in this application?
They are the Cheater HR Lift Rule Competition family, which are extremely aggressive competition profiles that are clearly categorized as a "Race Only". They were designed for "lift rule" racing with very fast opening rates and clearly present a durability issue in a marine engine.
Bob
#14
Re: Help With Blower Cam.
Originally Posted by rmbuilder
Fastlane40,
Because the 2 cams you listed are Hyd-Flat, do you intend on staying with the flats or converting to roller?
GPM,
What would be the advantage to running the 3299/3295 lobes in this application?
They are the Cheater HR Lift Rule Competition family, which are extremely aggressive competition profiles that are clearly categorized as a "Race Only". They were designed for "lift rule" racing with very fast opening rates and clearly present a durability issue in a marine engine.
Bob
Because the 2 cams you listed are Hyd-Flat, do you intend on staying with the flats or converting to roller?
GPM,
What would be the advantage to running the 3299/3295 lobes in this application?
They are the Cheater HR Lift Rule Competition family, which are extremely aggressive competition profiles that are clearly categorized as a "Race Only". They were designed for "lift rule" racing with very fast opening rates and clearly present a durability issue in a marine engine.
Bob
What's your recommendation Bob ?
Last edited by GPM; 01-17-2005 at 10:11 PM.
#15
MarineKinetics
Platinum Member
Re: Help With Blower Cam.
Some suggestions for a blower Cam.
A wide lobe separation (112*-115*) to reduce overlap and blow through.
Blower engines need less (2*-4*) advance. An early IVO is unnecessary. The intake column is pressurized and early openings increasing overlap. A 110*/112* ICL on a 114* Lobe sep would work well.
Increased exhaust volume requires blower cams to have additional ex duration to rid the cylinder of spent gasses. This is dependant upon the efficiency of your exhaust port. 8*-10* spread is a baseline reference.
Stock exhaust ports need an earlier EVO to blow down the cylinder. The negative of and early exhaust valve opening is the loss of some of the increased cylinder pressure. The negative of a late EVO is increased pumping losses. Optimizing your exhaust port will help, allowing you to delay the EVO, negating the pumping losses.
If you choose to go with a custom profile you need to determine your head flow and mechanical parameters, your peak torque/HP range, and then the cam can be calculated. I agree, staying in stock configuration with a flat tappet will limit lift
If not, (2) proven OTS flat tappet cams that provide reliable power(peak@ approx 5500 RPM) with moderate boost, valve train stability, and durability:
Lunati 02005
302*/308*…224*/234*….534”/.559”…114* LSA
2°BTDC 42°ABDC /
55°BBDC -1°ATDC
Crane 132561 H-228/312-2S-14 T1.2 (525 SC)
298*/306*…..228*/236*……530”/.551”…..114*LSA
5°BTDC 43°ABDC /
57°BBDC -1°ATDC
A wide lobe separation (112*-115*) to reduce overlap and blow through.
Blower engines need less (2*-4*) advance. An early IVO is unnecessary. The intake column is pressurized and early openings increasing overlap. A 110*/112* ICL on a 114* Lobe sep would work well.
Increased exhaust volume requires blower cams to have additional ex duration to rid the cylinder of spent gasses. This is dependant upon the efficiency of your exhaust port. 8*-10* spread is a baseline reference.
Stock exhaust ports need an earlier EVO to blow down the cylinder. The negative of and early exhaust valve opening is the loss of some of the increased cylinder pressure. The negative of a late EVO is increased pumping losses. Optimizing your exhaust port will help, allowing you to delay the EVO, negating the pumping losses.
If you choose to go with a custom profile you need to determine your head flow and mechanical parameters, your peak torque/HP range, and then the cam can be calculated. I agree, staying in stock configuration with a flat tappet will limit lift
If not, (2) proven OTS flat tappet cams that provide reliable power(peak@ approx 5500 RPM) with moderate boost, valve train stability, and durability:
Lunati 02005
302*/308*…224*/234*….534”/.559”…114* LSA
2°BTDC 42°ABDC /
55°BBDC -1°ATDC
Crane 132561 H-228/312-2S-14 T1.2 (525 SC)
298*/306*…..228*/236*……530”/.551”…..114*LSA
5°BTDC 43°ABDC /
57°BBDC -1°ATDC
Last edited by rmbuilder; 01-18-2005 at 08:07 AM.
#16
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Re: Help With Blower Cam.
GPM and Rmbuilder.Thanks for taking the time and helping me out.Will the 525SC cam fit in a 502HO GenV crate motor?If it will fit will it provide benefits over the standard cam?
#17
Geronimo36
Gold Member
Re: Help With Blower Cam.
Originally Posted by rmbuilder
Lunati 02005
302*/308*…224*/234*….534”/.559”…114* LSA
2°BTDC 42°ABDC /
55°BBDC -1°ATDC
#19
MarineKinetics
Platinum Member
Re: Help With Blower Cam.
Originally Posted by GPM
Look at the cam and the power MESA is getting out of a blown 383 small block, does it tell you anything.
Bob
#20
Re: Help With Blower Cam.
Originally Posted by rmbuilder
That its not a 502 crate motor
Bob
Bob
Last edited by GPM; 01-19-2005 at 09:58 PM.