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comp cams thumpr 279


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Am wondering if anyone has any experience with this cam. My brother bought an old truck (sorry, not a Z), and we think it is a stock 350 with this cam in it. Sounds really good but is very weak as far as power goes. The claim on this cam is that it gives you a big cam sound without effecting driveability. Is this possible? I know it has a large overlap. Truck has no low end and we are wondering if it is a tunning issue or is this cam a joke.

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....mild street engines with these cams that are loping a lot and sounding good, but have crappy power and performance.

....its all just a marketing ploy! These are designed/marketed for the crowd that wants a real rumpity sound for cruise nights and stuff like that, but otherwise, dont care how it runs. If your one of those guys, than these camshafts are for you. You will hear it coming, and it will be an attention getter at the car shows. It just wont run as good as it could(which may be a non issue for you if your just after the wow factor). Nothing wrong with that if this is your goal, just dont expect one of these cams to run as well as others.

 

Im sure you have heard all the old expressions like "the grass is always greener on the other side" or, "you cant have your cake and eat it too".... These expressions have come about because of the fact that You cant actually have your cake and eat it too......while standing on greener grass(once you walk on the grass enough it starts to die). These cams work the same way.

 

All the effort and energy invested in designing these camshafts is put towards making them sound a particular way. Thats your cake. Itll sound good, but itll suffer in other areas. This cam may sound great in your engine but not perform great. The best performing cam for your engine may perform great......it just might not sound as good. Sorry for the long rant, but I just wanted you to keep this stuff in mind, cause you gotta be sure of what you want your engine to do. There are better performing camshafts out there for sure, but they may or may not sound as good as youd like.

 

http://www.chevelles.com/forums/archive/index.php/t-169420.html

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That's kind of what I was thinking. Keep in mind, we did not pick this cam, it came in the truck. We are just trying to decide if we are going to yank it out or not. Care more about how it performs than what "Billy" thinks at the drive thru...

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not a bad cam for stock heads. But needs more than stock compression and more gear and more converter to make any power.

 

they add a lot of exhaust duration and a narrow lobe center angle to make a rough idle and to close the intake sooner. This works well with stock poor flowing heads.

 

I would use 9 to 9.5:1 cr (not stock 8:1)

3.55 to 3.73 gears

2500 stall

headers with 2.5 inch pipe and a set of dynomax super turbos.

 

 

if you don't plan to change the compression, gears, and stall then install a smaller cam. a cam the size of a compcam 252H (252/252, 206/206 at 0.050) would be a good match for a stock 350 and driveline.

 

lastly, use zddp oil additive with your new cam. (http://www.zddplus.com)

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  • 1 month later...
not a bad cam for stock heads. But needs more than stock compression and more gear and more converter to make any power.

 

they add a lot of exhaust duration and a narrow lobe center angle to make a rough idle and to close the intake sooner. This works well with stock poor flowing heads.

 

I would use 9 to 9.5:1 cr (not stock 8:1)

3.55 to 3.73 gears

2500 stall

headers with 2.5 inch pipe and a set of dynomax super turbos.

 

 

if you don't plan to change the compression, gears, and stall then install a smaller cam. a cam the size of a compcam 252H (252/252, 206/206 at 0.050) would be a good match for a stock 350 and driveline.

 

lastly, use zddp oil additive with your new cam. (www.zddplus.com)

 

Ive used the 252H in the past. Made more power and better mileage than the stock cam. It also makes for a good towing camshaft. For a performance car I would go up to a 260H though.

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Am wondering if anyone has any experience with this cam. My brother bought an old truck (sorry, not a Z), and we think it is a stock 350 with this cam in it. Sounds really good but is very weak as far as power goes. The claim on this cam is that it gives you a big cam sound without effecting drive ability. Is this possible? I know it has a large overlap. Truck has no low end and we are wondering if it is a tuning issue or is this cam a joke.

 

the WHOLE THUMPER LINE of cams is a BAD JOKE in my opinion even comps tech guys won,t suggest them if they are being honest if your asking about making the best possible potential power from any given duration.

think about it a bit the whole concept is to change the exhaust duration timing so it idles like a much larger cam, its the lopey sound, not the the volumetric efficiency or power potential that was the main criteria.

 

look impressive?

 

http://www.compcams.com/thumpr/dynoresults.asp

 

heres the specs on that green line cam,made about 375 hp

 

http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=109&sb=2

 

using comps own dyno charts they show a cam with LESS duration matched with less compression makes 390hp at a lower rpm in an engine with less potential

 

http://www.compcams.com/Technical/DynoSheets/XE284H-10_001.asp

Edited by grumpyvette
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