Anyone Use A Thumpr Cam?

[westie47]

Has anyone used the Comp Cams Thumpr in a small block? I want to put a new, choppy cam in my 360 when I have it out. I love the way these cams sound. Will it work with stock heads etc? I do have an aftermarket intake, not sure what's going on inside the motor yet, I'm assuming it's stock.

 

[slepr1]

I've never used that cam but if you are looking for a choppy cam, call Hughes. I called them for a recommendation on a cam (given my engine specs) and bought one that sounds really nice and performs even better.
http://www.hughesengines.com/Index/index.php

 

[BeepBeepRR]

Before just throwing a cam at it you need to see if that cam requires more spring pressure for the valves as well as the need for longer/shorter pushrods.

 

[modelmaker]

Has anyone used the Comp Cams Thumpr in a small block? I want to put a new, choppy cam in my 360 when I have it out. I love the way these cams sound. Will it work with stock heads etc? I do have an aftermarket intake, not sure what's going on inside the motor yet, I'm assuming it's stock.

As someone who was doing the same exact thing DON'T. IT DOESN'T WORK! YOU WILL MAKE THE ENGINE A PIG.

Call Hughes cams and give them the specs of your car. The combo of the parts is what make it work.

 

[westie47]

I will be giving them a call next week then. Thanks for the advice!

 

[Bighead440]

The "lopey sound with driveability" cam is not a new concept. Crower's Hi-Draulic Hauler cams used to do that back in the '70s, but then they changed them around to more of a midrange cam, requiring a more serious build on the engine. The Comp "Dual Energy" series offers lope without requiring a stall converter, and has a broad powerband with quiet operation/longevity from the lobes. A 255DEH works grand in a stock 318 (8:1 compression, 2bbl etc.) and the 265DEH is the one for a stock 360. I used a 275DEH in a 400 with some head milling to get the compression up to an honest 9:1, so it might work in a 340 with factory "10.5:1" (9.5 actual?) or a 360 with flat-top aftermarket pistons, etc. They are now listed in the "Specialty Cams" section of the Comp catalog, which is a shame, because they work really well. They are really pushing the Thumpr line and Extreme this and that, nowadays.

 

[PRHeads]

The Thumpr series of cams utilize lobes that are pretty easy on parts.

Assuming you plan on using stock heads, the stock springs will not really be suitable.
(They recommend a dual spring for that series, so removing the heads and machining the heads to accept those springs would be necessary).

The Thumprs are pretty choppy, so careful selection of the converter and gears is important, and carbs with 4 corner idle would be preferred, and you’ll want headers.

They’re not really a good match for Sniper/FiTech style EFI systems.

If the plan is to install one in a stock low CR 360....... it would be best to stick with the smallest one.

Something like a Howard’s 712221-08 would still give you a little chop, but can be used with springs that fit the heads without machining.

The Comp XE268 also has a nice sound to it in a mild SB(but def not as choppy as a Thumpr), and still uses a single spring.

 

[wyrmrider]

If you have enough cr to use a 275 use the XE275HL
UD harlod made many upgrades from the Comp xe line to the Ultradyne line which still used .842 lobes but better than his older comp designes-to the Lunati Voodoo line which outperforms all of the above. His Custom Cams versions were his best- now owned by Howards Idk if they list them seperatly

 

[westie47]

Thanks for all the advice. I just finished pulling the motor and pressure washing it. I have 1976 360, casting #4006830-360-3.

I'm guessing this is a low compression engine. It has an aluminum intake, but my guess is it's all stock. I will check the heads/cylinders when I change head gaskets.

 

[wyrmrider]

timing chain