The message to which you are about to reply is shown first. GO TO REPLY FORM



 VIEW    REPLY TO THIS MESSAGE    PRINT   SAVE 

Cam & Valve Spring advice .... 140-160

No time right now for a long cam disertation. But breifly, a race cam is designed for peak HP in a comparatively narrow power band at the top of the rpm range, most likely from 4,000 to 7,000 or 5,000 to 8,000. Low end torque was usually not important in the design and was sacrificed for high end power. ( try having to rev to 4,000 rpm to pull away from each stop ) I say "was" because these are old cam designs. More modern cams, even for racing, strive for a broader power band and the average HP over a specified rpm range rather than peak power.
With modern changes in cam lobe design you do not have to have a long duration high lift cam to make decent power, and do not have to sacrifice low end power.
In any case, a race cam is not what you want on the street. And any cam with that much lift ( .480 ) is going to require special valve springs, in fact stronger than the 625/626 that Isky shows as their dual spring for B20.

Never assume that a previous owner did anything that was logical or reasonable.
Do not consider this cam similar to the D cam. And remember that advertised cam specs tell you very little about the actual cam design as nothing about the lobe shape is specified. 2 cams with the same duration at .020 and the same max lift can have entirely different lobe shapes, and markedly different durations at say .250 valve lift.

Last word. Everything has to be matched to work together.

Regards,
John
V-performance.com






USERNAME
Use "claim to be" below if you don't want to log in.
PASSWORD
I don't have an account. Sign me up.
CLAIM TO BE
Use only if you don't want to login (post anonymously).
ENTER CAPTCHA CODE
This is required for posting anonymously.
OPTIONS notify by email
Available only to user accounts.
SUBJECT
MODEL/YEAR
MESSAGE

DICTIONARY
LABEL(S) +
IMAGE URL *
[IMAGE LIBRARY (UPLOAD/SELECT)]

* = Field is optional.

+ = Enter space delimited labels for this post. An example entry: 240 muffler


©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.