Thumper Cam
 

We just got this 21 Foot Scarab. Its got a 350 with Vortec heads and Edelbrock intake on it. The engine was rebuilt last year its fairly fresh. I am in the process of some major fuel system up grades and ignition up grades. I have the dudes number that had it before the last guy I got it from so I can find out what was done to the motor. The motor runs smooth no lumpy idle.

I am not going to do it right a way but I wanted to get your guys prospective on the Thumper cam. I beleive there good from about a grand up through about 5500 which woulc be good for a boat. I want that nasy lumpity Lumpty idle it already has the through hull exhaust so why not put this in down the road?

I already know to do the valve spring up grade check for spring binding replace the valve seals while you got it appart etc. Just want to know what you guys think of the cam?



What do you guys think?:evilb:

i think the cam is ok for a car, but its not advised to use a cam for auto in a boat, and i think many will agree

Your new here so I will take it easy on you, there is way more to it than throwing in a THUMPER CAM. You will need exhaust, oil system upgrade and numerous other parts to make it all work. Marine cams are set up different than car cams. With a name like BAD ASS SCARAB I am a little disapointed. With that name you should have twin 1000HP engines running 100MPH. Maybe a name like SLOW SCARAB, or WANABE SCARAB would be more better :lolhit:

:popcorn:

Jeffs
 

Well Jeffs wavs I didnt come on here for you to be and judgemental ass. I just wanted to get some ideas from the guys on here and get there feed back.

Sorry if I don't have a huge wad of cash to suit you. I was pretty impressed with the guys on here untill you put up your condensinding response.

I have been building engines a long time probably longer than you. I have built numerous muscle cars and know engines inside and out I not a dumb ass.

I have a 65 GTO convertible that I have restored from the ground up and its pushing about 450 HP.

I also have a 69 Coronet RT Convert Matching no 440 Mag power windows power top factory AC Factory Hemi Orange
You wouldnt know a 440 if it bit you in the ass!

So take your condinsending opinons and stick it where the sun dont shine!

I didnt come on here to take this kind of S##t from you or anybody eles!

All I was asking was some imput on the Thumper Cam
I didnt see any place on my Q and A about please give me some un called for S##T from some ill educated person as your self!:bsflag:

The LSA of that series of camshafts is 107 degrees, rendering it a reversion risk unless you are running a dry exhaust. Look for a camshaft with less overlap, an LSA of 112+.

Thank you !
 

See that is what I needed. I can build Auto Engines but not sure on marine application as far as cams.

Nice to see some professional helpfull people on here.

Thanks:}

Don't take things so personal. When you pick out a name like BADD ASS SCARAB, that seems pretty cocky. I don't call myself BADD ASS BAJA, and I am sure my boat is way faster than yours.
To answer your question, that cam is not made for a boat. I do know a guy that has a boat like yours with a 383 stroker. He has it running about 72 MPH, I still would not call it a BADD ASS SCARAB.
Take some time and do a little research, there are 100's of post hear that talk about cams. A lot of us use RMbuilder for custom roller cams, when you are serious give him a call and he will give you a education about marine engines.
The best thing to do would be to leave it alone and enjoy boating and do not let the speed bug get you.

Ok Point taken
 

I did not or do I imply I have a Bad Ass Scarab every body on here thinks I have some inflated ego and my boat is better than anybodys eles. That is furthur from the truth. I am very grounded and I am not that way ok guys. Its just a user name not to be takin litterly ok?

I was thinking about puting in a cam way down the road . Just thinking about it. If I got 50 mph out of it I would be happy with it right now.

So I want to get somthing clear guys. I dont have a Bad Ass Scarab its just a user name and that is it . I probably have the slowest boat in this group of guys on here.

I am just here to talk to othere guys and get there prespective and if I have any knowledge on a subject try and help out.
I will take your advice and just go ahead with the upgrades for fuel and ignition sytem and get the engine componets Coast Guard Approved
Is that cool? Thanks Guys.
The guy with the slowest boat on the internet

Is that like a 3/4 race cam or an RV cam? Both are HOT!

Heres the Cam I was talking about
 

Brand COMP Cams
Manufacturer's Part Number 10-600-5
Part Type Camshafts
Product Line COMP Cams Thumpr Hydraulic Flat Tappet Camshafts
Summit Racing Part Number CCA-10-600-5
UPC 036584212744

Cam Style Hydraulic flat tappet
Basic Operating RPM Range 2,000-5,800
Intake Duration at 050 inch Lift 227
Exhaust Duration at 050 inch Lift 241
Duration at 050 inch Lift 227 int./241 exh.
Advertised Intake Duration 279
Advertised Exhaust Duration 296
Advertised Duration 279 int./296 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.491 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.476 in.
Valve Lift with Factory Rocker Arm Ratio 0.491 int./0.476 exh.
Lobe Separation (degrees) 107
Computer-Controlled Compatible No
Grind Number 279TH7
Valve Springs Required Yes
Camshaft Manufacturers Description High performance street, stock converter ok, best with 2000+ converter and gears. Choppy/thumping idle.
Quantity Sold individually.


COMP Cams is bringing the musclecar sound back and it's nastier than ever! Let's face it--few things serve to grab our attention at a car show or cruise night more than a car with a thumping, high performance idle. In fact, one of the most frequent questions fielded when customers call our tech line is, "what camshaft will give my car that mean-sounding idle?" In an ongoing quest to provide you with the performance and sound you demand, the COMP Cams engineering team proudly introduces the Thumpr series of camshafts. The Thumpr camshafts are a new series of hydraulic flat tappet camshafts. The lobe profile and grind characteristics of these new Thumpr camshafts use a combination of early exhaust valve opening, long exhaust duration, and a generous amount of intake and exhaust overlap to maximize the rough-idling characteristics of the cams. They give you a seriously aggressive exhaust note without negatively impacting the power output or streetability of the engine. Thumpr camshafts are available in three different grind profiles; each one will produce a rough, racy exhaust note and impressive amounts of horsepower and torque within a different rpm range.

Warranty


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Take a look at these they work real well, simple to install and wont rust up like the MSD. http://www.performancedistributors.com/marinedui.htm
A good running stock 350 should push that boat to 55MPH. The other thing is are you running a Alpha or Bravo? If its a Alpha I would limit it to about 300HP.

I got the ignition and fuel system
 

I had the old type points dist so I up graded with a marine HEI with a 60,000 KV coil and sprial wound ingition wires. I ordered a new Holley 650 CFM Marine Spread bore . I have to completely replumb the fuel system. They put and Auto Motive 780 double pumper and Auto fuel lines. I am going totally Stainless on all the fuel lines in the engine compartment.
The only rubber line will be the Coast Guard Approved inlet from the tank. The rest will be either steel or Stainless.
I am running a Alpha one drive. The 300 hp limit is a good call don't want to tear it up. The dude had a blown small block in it but blew up the engine. Then he put this vortec engine in it.
I have the boat on blocks right now I have to get the trailer restored no brakes bad paint bunks shot new wiring etc. Once I get the trailer done and the boat back on I can start on it.

with those dist. you can delete the thunder bolt modules then? are they a direct drop in or do you gotta play with weights to set the advance? the price is sure good on them

Are you asking about The DUI?
A lot of us use them, I have the computer controlled ignition, my PCM controls the advance. They do have a simple one wire system also. The TB ignition is a really good system, if it is working correctly you could just rebuild it.

High Energy Ignition
 

The type I have in there now is just a standard marine points type dist with an external coil.

The dist I have now for it is based on the GM HEI dist has the same cap and rotor ignition module, pick up coil, as the autmotive type but this Dist is Coast Guard approved and does not have the vaccumn advance like the Automotive counter parts.
It also plug and play one wire hook up. If anything takes a crap out on the road just go down to your local Auto Parts and you good to go.:evilb:

Fixx
 

here is the one im using in my x boat..it works good with vortec heads as well and a friend was using it in his classic as well,great cam and has a tom of midrange tq and upper hp..i spin mine up to 6200 at times but you wont need to..i have alunimum heads and 6'' rods with a light weith crank,thats all im telling :drink:

http://www.jegs.com/i/Comp-Cams/249/...oductId=747427

here is what the idle sounds like..

http://www.youtube.com/watch?v=dLdeNiyk0Ew

good luck with your mods;0

Hell yeah
 

Freekin sweet! So this cam is good for mid to high range how about out of the hole? In your light boat would be good but what if you have a heavyer boat like mine in a cuddy? Thanks for the tip

yes i was talking about the ones in the link you posted. my TB Iv seems to be fine. but the boat has not seen the water only the ear muffs since the motor swap.
what kinda of speed do you get out of your 236 with 500hp? what motor are you running?

Fixx
 

in my boat i put the cam in at *112 like it read on the cam card becaause its lite,with your boat i would advance it *2 which will gige you more low end..even at *112 its still a rocket out of the hole,sometimes i have problems with the prop hooking up and i run a 24pitch prop most of the time.

Ok
 

Sounds good thanks!