changed my blown 440 from solid to hydraulic roller

[jgnewhall]

I've changed from a solid flat tappet to a hydraulic roller cam . I guess that it's normal for the car to be quieter thru the exhaust, seems too quiet though ( to my ears ). Is it true that I'll now have more low end torque , but lose a few horses due to the change ? I was looking for a little more of a less maintenance valve train . Thoughts?

 

[SwedCharger67]

If the cams are not identical I think it's quite normal that the sound is different. A more quiet sound doesn't need to mean less power, it could actually mean that your engine is now running more efficiently.

My powerless, low compression and overcammed 383 was louder than my new, high compression 512 with the same exhaust system.

In Formula 1 they say that the quieter an engine runs, the more efficient it is.

 

[benno440]

todays solid cams are actually less maintenance then hydraulics, set and forget

 

[Tempest 455]

Probably a lot less duration @ .050". Yes it will be quieter through the exhaust.

Will never forget this. We changed heads, cam intake on a buddy's car. Was the same headers, mufflers, no exhaust changes at all. However, the changes on the motor were significant. MUCH better headflow, huge solid roller, tunnel ram and much more carb. The car was literally TWICE as loud with the same exhaust as the result of increased HP and exhaust duration.

Less HP and duration, less noise.

 

[Badvert65]

Just curious, what cam did you pick/ specs?
I am building a 440 blower motor and about the only thing I haven't, so far, gotten is the cam.

 

[coloradodave]

todays solid cams are actually less maintenance then hydraulics, set and forget

Benno, there are some young, impressionable minds out there that might want to question that statement....lol. Maybe the words got jumbled because they had to travel so far...

 

[benno440]

Dave, I was told by patrick at prosystems, tony at brinks performance and lunati the same as above statement, correct me if i am wrong

 

[coloradodave]

Certainly wouldn't want to argue with THAT brain trust but this is why I said that: Assuming you adjust both a hydraulic and a solid cam correctly, the maintenance SHOULD be no different. In my opinion, setting the lash on a solid cam takes a few sessions to get it stable, depending on whether you're running aluminum or iron heads and what valve train you're using (steel, aluminum or SS rockers). Expansion rates of all those materials are different and, although you can make an educated guess, my experience has been that you'll pull the valve covers several times before you end up with the recommended lash when the motor is hot. Hydraulics, you set the preload cold to what the manufacturer suggests and you're off and running. Some of us **** types will check it when hot, but generally, the cold setting works fine.

 

[benno440]

ahh yeh i totally agree with you there

 

[jgnewhall]

Thanks for the replies. I have another observation. The car's blower now surges . It never did that before... ever. Is that normal? I went from a larger cam to a slightly smaller cam.

 

[IQ52]

Thanks for the replies. I have another observation. The car's blower now surges . It never did that before... ever. Is that normal? I went from a larger cam to a slightly smaller cam.

I think I would ask an engineer from the cam company (and not somebody from the hotline). Did you buy an off the shelf NA cam or one designed for booosted applications?

 

[Cranky]

Can timing can also make a difference in the exhaust note. One that's advanced a bit will usually idle better and sound more mild than one that's retarded a bit.

 

[jgnewhall]

I bought a custom grind for a blower motor for my car.

 

[jgnewhall]

this is in reply to Badvert65 .

 

[lxmodguy]

There are lots of folks that have varying opinions on blower cams. A good blower cam for your motor might be more like 230/240 .550 .570 on a 116LSA and a 114 ICL. Old school cam designers always think the LSA has to be 110, 112 etc. Its not best for the blower apps. Especially when the intake to exhaust ratio doesnt support it. Overlap bleeds of boost. A few degrees of negative overlap will make the car idle better, build boost faster, and hold boost better at peak.