Search found 48 matches
- Wed Apr 03, 2024 8:56 am
- Forum: Engine Tech
- Topic: Solid roller spring suggestions please
- Replies: 15
- Views: 1122
Re: Solid roller spring suggestions please
Depending on what the application of this engine and what your goals are, you have a couple options. If this is going to be a "max effort" kinda deal where you are trying to make as much HP as possible, I would highly suggest looking at the PAC-1427H conical spring. If this is more of a st...
- Tue Apr 02, 2024 8:46 am
- Forum: Engine Tech
- Topic: Solid roller spring suggestions please
- Replies: 15
- Views: 1122
Re: Solid roller spring suggestions please
What Rocker Ratio?
- Fri Jan 19, 2024 8:57 am
- Forum: Engine Tech
- Topic: LS Valve weight VS spring pressure
- Replies: 94
- Views: 5428
Re: LS Valve weight VS spring pressure
I would entertain the PAC-1222X installed 1.750"
201lbs seat and 470 open.
201lbs seat and 470 open.
- Fri Jan 19, 2024 8:30 am
- Forum: Engine Tech
- Topic: LS Valve weight VS spring pressure
- Replies: 94
- Views: 5428
Re: LS Valve weight VS spring pressure
A big question not answered is what rocker arms are we using? A factory or roller setup?
- Wed Dec 13, 2023 8:59 am
- Forum: Engine Tech
- Topic: Valve spring properties order of importance
- Replies: 76
- Views: 65729
Re: Valve spring properties order of importance
Frequency - This one is very hard to dictate and requires a lot of mathing to really determine desired frequency. With the proper information, you can figure out your hertz range and you would want to choose a spring that the natural frequency is not in the power band of that hz range. Not many peo...
- Tue Dec 12, 2023 10:15 am
- Forum: Engine Tech
- Topic: Valve spring properties order of importance
- Replies: 76
- Views: 65729
Re: Valve spring properties order of importance
List your order of importance of valve spring properties: Spring rate Installed height Distance to bind Pressure @ max lift Seat pressure Diameter Type (straight, conical, beehive etc) Frequency Number of coils Anything else 1 - Type of spring - this will be dictated by tappet type, max lift and ma...
- Mon Oct 16, 2023 9:28 am
- Forum: Engine Tech
- Topic: Hyd. Roller lifters
- Replies: 2
- Views: 470
Re: Hyd. Roller lifters
Contact Ken @ Motorsports Unlimited. 216-433-7223 - been doing BBC marine stuff for years.
- Fri Sep 15, 2023 8:58 am
- Forum: Engine Tech
- Topic: valve spring debate: conical vs std duals vs beehives
- Replies: 28
- Views: 3440
Re: valve spring debate: conical vs std duals vs beehives
0.730" lift is pretty healthy for any single to keep up with, usually just not enough rate and seat load. Now if you had time to test lobes and a spintron, I am sure you would be able to come up with a killer single spring package. This usually takes some time and quite a bit of money, somethin...
- Wed Sep 13, 2023 9:24 am
- Forum: Engine Tech
- Topic: Broken valvspring.
- Replies: 47
- Views: 7295
Re: Broken valvspring.
PRI new products will be exciting for PAC racing
- Fri Aug 04, 2023 1:19 pm
- Forum: Engine Tech
- Topic: Rear mounted turbo's?
- Replies: 16
- Views: 1751
Re: Rear mounted turbo's?
As heat energy was mentioned as a downside, the upside is the heat lost in the intake travel too.
- Wed Apr 26, 2023 1:57 pm
- Forum: Engine Tech
- Topic: LS Rocker Pedestals
- Replies: 3
- Views: 393
Re: LS Rocker Pedestals
Ive had mine milled down to get better geometry with a factory rocker. Not sure if this helps you but yes, they can be milled.
- Wed Apr 26, 2023 11:30 am
- Forum: Engine Tech
- Topic: Valve spring weight
- Replies: 33
- Views: 2940
Re: Valve spring weight
The nice thing about conicals is the design itself can do more with less, meaning you can control valve acceleration loads with less pressures than conventional double springs. So not only do you lose mass in spring and retainer, the varying coils diameter have its own frequency through the spring ...
- Wed Apr 26, 2023 9:02 am
- Forum: Engine Tech
- Topic: Valve spring weight
- Replies: 33
- Views: 2940
Re: Valve spring weight
The nice thing about conicals is the design itself can do more with less, meaning you can control valve acceleration loads with less pressures than conventional double springs. So not only do you lose mass in spring and retainer, the varying coils diameter have its own frequency through the spring ...
- Mon Apr 17, 2023 4:15 pm
- Forum: Engine Tech
- Topic: Valve spring weight
- Replies: 33
- Views: 2940
Re: Valve spring weight
That's why in 2019 I ran stock rockers on my Vortec 406 over the roller rockers I had at the time. More weight on the valve tip means earlier valve float and IMO that's what roller rockers can do to an engine. I have never seen and better track performance with roller rockers on my street engines t...
- Mon Apr 17, 2023 3:53 pm
- Forum: Engine Tech
- Topic: Valve spring weight
- Replies: 33
- Views: 2940
Re: Valve spring weight
Someone correct me if I am wrong, but I would think that if in any point in your motors operating range you have spring surge taking place then at that point in time the whole / total mass of the spring can be taken into account since it's not touching the head any longer. That would be a serious p...