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boop coupe (aka boop coupe) [ View ] [ frank8142@verizon.net ] [ Car Ads ] [ Blogs ] clarksville, Maryland  Frank Jones

I am considering a comp-thumper cam for my sbc 350. Called the tech line to ask what they recommend. Needless to say, the guy wasn't real helpful. My question is, can you use a thumper cam & lifter kit with stock push rods, valve springs & rockers? Can you add their "beehive springs" without changing rockers & push rods. Same questions for flat tappet can and roller cam. I have a rebuilt 350 with about 20,000 miles on it, not sure if its worth installing a 1000.00 roller cam for mid street application. Anyone adding one of these toys to their streetrod?

Comments

Posted by Starfire  -  08/15/2008 10:35 AM Use stock push rods with a cam like that and the first time you fire it up you'll have bent push rods all over the place. Use only heat treated seamless push rods with a cam like that. Cams and valve springs need to be matched to achieve proper engine breathing. Roller cams will improve power and even fuel economy. If you decide to go roller cam, just be aware retro roller lifters are not going to be cheap and you will have to use a different push rod length from stock. Roller rockers with adjusters are highly recommended. In simple terms once you start messing with the valve train, you have to do it right or you'll have a very poorly running engine. Starfire [ View ] [ Email ] [ Blogs ] [ Car Ads ] Weimar, Texas   Posted by boop coupe  -  08/15/2008 10:53 AM Thanks , they do have a kit with cam, lifters and matching valve springs. Thay also have a push rod-rocker kit. Finally talked with someone from comp that told me not to use stock push rods and that you can measure the push rod or order their p.r. - rocker kit. I am thinking of using the thumper flat tappet kit with double roller timing chain, lifters and valve springs. I need to call one more time to see which pushrod- rocker arm kit I should use. Thanks for the info. Frank Jones [ View ] [ Email ] [ Blogs ] [ Car Ads ] clarksville, Maryland   Posted by bigdude  -  08/15/2008 11:19 AM Thumpers have the sound but lack in perf. Why not go with an ext energy 268 and get the sound and performance I have had three of them and people think Im running a huge cam. resident know it all [ View ] [ Email ] [ Blogs ] [ Car Ads ] Three Rivers, Michigan Charter Member since January 2004   Posted by da34guy  -  08/15/2008 11:24 AM Greg (Big Dude) is right on the money! A comp 268 with a 2 degree button in it will give ya all the Thumpty thump ya want and keep $2 - 300 in yer pocket Much better power range also. Kruzin in AZ Don [ View ] [ Email ] [ Blogs ] [ Car Ads ] Prescott, Arizona Charter Member since October 2001   Posted by boop coupe  -  08/15/2008 11:52 AM That sounds like a nice cam. Can you tell me what rear ratio you run with this cam and where is the torq range? Also , how radical is the exhaust sound? Do you recommend using matched springs and changing the push rods & rockers or can that cam run well with stock components? Frank Jones [ View ] [ Email ] [ Blogs ] [ Car Ads ] clarksville, Maryland   Posted by bigdude  -  08/15/2008 11:58 AM In my current ride the exhaust sounds real cool and am running z-28 springs and harland sharp rollers with hardened rods. Im running 411 gears I believe- with a 200 r Torq is about 2000-5000 If Shine ever gets off his butt he can add to this. I had the same cam in my poor old Nova and it woke that up also- 3:55 gears resident know it all [ View ] [ Email ] [ Blogs ] [ Car Ads ] Three Rivers, Michigan Charter Member since January 2004   Posted by CK  -  08/15/2008 12:15 PM Just installed the Mutha Thumpr in my Camaro a few weeks ago, cam and lifters for a hydrolic about $300 from Summit. fresh engine 355, 10 to 1, basic heads,373 gears. Sounds pretty good and lots of power. Ken CK [ View ] [ Email ] [ Blogs ] [ Car Ads ] mililani, Hawaii   Posted by boop coupe  -  08/15/2008 12:51 PM I just got off the phone for the third time with comp-techs. He had alot of good to say about the xtreme energy 268 except for the exhaust sound. Said it doesn't sound very radical at all...any one want to add to this? The kit 249-k12-242-2 from jegs is 336. for cam, lifters, springs, timingchain & gears. Also comp has a matched rocker arm / pushrod kit for 199.00 to with it. Basically that all your need. Nice power curve, plenty of vacum, but I would still like some choppy idle....fast is fast...& ...cool is cool... Frank Jones [ View ] [ Email ] [ Blogs ] [ Car Ads ] clarksville, Maryland   Posted by bigdude  -  08/15/2008 01:05 PM I wished you lived closer so you could hear mine out the back. Its pretty noticable! resident know it all [ View ] [ Email ] [ Blogs ] [ Car Ads ] Three Rivers, Michigan Charter Member since January 2004   Posted by DaveHughes  -  08/15/2008 01:39 PM Check out my post back this winter. I installed a thumpr cam in a 260hp Gm crate motor and couldnt be happier- Use there springs around 70.00 and the stock pushrods are fine- unlike other advice you read here earlier I have been there and done exacly what you are doing and it works fine--- DO NOT go any bigger than the smallest thumpr cam UNLESS you want to run a stall convertor- I have the smallest one and it is border line with a stock converrtor. I didnt want a stall because I wanted taller gears for highway cruising. I drove it to the street rod nots and got 18+ mpg and it sounds like a race motor.. Any help I can give you I will.. I suggest going to youtube and search thumper or thumpr cams (notice the spelling) There is a video of a sbc on a dyno with each of the thumpr cams installed to give you an idea of what they sound like.. Dont get me wrong I was tempted to go with the biggest but I am glad I didnt because mine sounds great and still very drivable..good luck DaveHughes [ View ] [ Email ] [ Blogs ] [ Car Ads ] seaman, Ohio   Posted by CK  -  08/15/2008 02:01 PM Yes Dave is right about the convertor, Mine has a reworked stock one to get about 2400 stall. Just listen to the manufacture on stall requirements. I have stock type springs and rockers on my heads, dont plan on racing it only cruzing. Ken CK [ View ] [ Email ] [ Blogs ] [ Car Ads ] mililani, Hawaii   Posted by cr55  -  08/15/2008 03:54 PM don't go for the big cam, you'll be sorry that you did . Sometimes the bigger cam makes the car slower depending on what you have in the motor. If you're looking for the sound only, listen to Big Dude!.....CR I thought that I knew it all , but.. [ View ] [ Email ] [ Blogs ] [ Car Ads ] dover, Delaware   Posted by Crazyhorse Rod Shop  -  08/15/2008 04:07 PM i run the 268excomp in everything i build. you dont need anymore cam. i dont time mine to the frigin moon so i get a real roller sound. i like to hear it rolling the cylinders. all i change is the springs. power range is where you spend all your time. dont poke the porchdog........he bites [ View ] [ Email ] [ Blogs ] [ Car Ads ] BLUFF DALE, Texas Charter Member since March 2003   Posted by DaveHughes  -  08/15/2008 09:49 PM the thumpr is designed purely for sound.. -imho- its the perfect streetrod cam. They make up the sound mostly in lobe sep and duration and not so much lift so its easy on componets but WILL NOT greatly improve performance.. If you want a race cam this aint it- If you want it to sound like a race cam and still be well mannered then put in a thumpr.. DaveHughes [ View ] [ Email ] [ Blogs ] [ Car Ads ] seaman, Ohio   Posted by boop coupe  -  08/18/2008 07:49 AM Hey Shine, In your opinion, what kind of exhaust rap does the 268 cam have? Thanks for all the help. Frank Jones [ View ] [ Email ] [ Blogs ] [ Car Ads ] clarksville, Maryland   Posted by Crazyhorse Rod Shop  -  08/18/2008 07:56 AM good rumpy idle. good low end power. i use it in everything. i think the 262 gets a little better millage but not enough for me to change. keep in mind it is the extreme energy that i use. dont poke the porchdog........he bites [ View ] [ Email ] [ Blogs ] [ Car Ads ] BLUFF DALE, Texas Charter Member since March 2003   Posted by boop coupe  -  08/18/2008 10:45 AM Right, the Comp extreme energy 268 kit with lifters, valve springs and double roller timing chain. Also add to that their valve train kit with matched roller rockers and push rods. The cam I am talking about is their flat tappet cam. Frank Jones [ View ] [ Email ] [ Blogs ] [ Car Ads ] clarksville, Maryland   Posted by rat fink  -  08/18/2008 03:24 PM If you want to get a LITTLE bit crazy......what about a hydraulic roller cam set up ??....for more "thumpity"...just look at the overlap specs as Dave says. KEN COPE [ View ] [ Email ] [ Blogs ] [ Car Ads ] RIGA, LATVIA, Other Charter Member since March 2008   Posted by 50pickup  -  08/19/2008 04:57 PM I am looking at swapping in a 350/290HP crate motor and I am wondering about the cam in it. It is advertized as .450/.460 lift and 114 degree (kinda wide) lobe seperation. No durations figures are given. What kind of idle characteristics does it have? Must be a lot of these engines out there, so Id like to here some comments from owners. 50pickup [ View ] [ Email ] [ Blogs ] [ Car Ads ] POTTERVILLE, Michigan   Posted by da34guy  -  08/19/2008 05:27 PM Very stock smooth idle Don [ View ] [ Email ] [ Blogs ] [ Car Ads ] Prescott, Arizona Charter Member since October 2001   Posted by DaveHughes  -  08/19/2008 05:35 PM that crate motor will sound like a sewing machine- There a great engine, but they dont have any lope to it at all. Take that engine and put the little thumpr in it and you will be happy.. DaveHughes [ View ] [ Email ] [ Blogs ] [ Car Ads ] seaman, Ohio   Posted by ramblinrelic  -  08/19/2008 11:14 PM i have heard dave hughes car sounds great . i would recommend it highly and it is still very driveable. and it is in a really nice car his car sounds like something john force might drive on the street cooool ramblinrelic [ View ] [ Email ] [ Blogs ] [ Car Ads ] SEAMAN, Ohio   Posted by TYCHOOCHOO  -  08/20/2008 10:27 AM Hey Dave, give me some specs on you engine. I'm thinking of doing some work on mine. You can e-mail me if you want. Tommy choo choo [ View ] [ Email ] [ Blogs ] [ Car Ads ] MT. SINAI, New York Charter Member since June 2007   Posted by da34guy  -  08/20/2008 10:30 AM Now the next ??? All the sound isn't made just by the cam, Ya need the right exhaust system to finish the job. Did I just open up a can of worms or what??? Don [ View ] [ Email ] [ Blogs ] [ Car Ads ] Prescott, Arizona Charter Member since October 2001   Posted by DaveHughes  -  08/20/2008 10:34 AM hey tommy- my engine is just the 250hp gm crate- only mod is the thumpr cam- Its really not as wild as ramblinrelic said. but it does have a choppy idle..my car sounds like a race motor--The one he just sold HAD a race motor...lol-- Mine just sounds mean...his WAS mean....but seriously for a streetrod engine it really works out great imho.. DaveHughes [ View ] [ Email ] [ Blogs ] [ Car Ads ] seaman, Ohio   Posted by 50pickup  -  08/20/2008 11:50 AM Im sold! I got a sewing machine now, it's gotta go! Just listened to the Youtube vids! Sounds pretty convincing. I've got shortie headers, 2 1/4" pipes & Thrush turbo muffs that are a little too quite. Can't rap the pipes hardly with them turbos. I'll likely switch to some Flowmasters after the engine goes in. 50pickup [ View ] [ Email ] [ Blogs ] [ Car Ads ] POTTERVILLE, Michigan   Posted by DaveHughes  -  08/20/2008 10:18 PM hey tom I have the 3 chambered flowmasters on mine and I will likely change mine to the 2 chambered as soon as I get my buddy who owns the muffler shop (ramblinrelic) to get busy...the 3 chambers are a little too quite for me.. The youtube video is what sold me too!!It is too cool! make sure you order there springs to and you will have no problem..Good luck! DaveHughes [ View ] [ Email ] [ Blogs ] [ Car Ads ] seaman, Ohio   Posted by boop coupe  -  08/22/2008 10:18 AM Been talking with the techs at Comp Cams. They tell me the extreme energy 268 hyd. cam can be run with the stock valve springs, rocker arms and push rods. I was ready to order the cam when I read in the specs that it says " don not use stock valve springs". The complete kit they sell with springs are not much over stock. The spec sheet says use 981-16, which are beehive springs. I am a little confused. Man, it's hard to get these guys on the phone. So far I was thinking of the 268 cam & lifter kit and use the RPM1412-16 magnum pushrods and rockers with roller tips. This cost more than the cam and I am not sure it's worth th money for streetrod application. Frank Jones [ View ] [ Email ] [ Blogs ] [ Car Ads ] clarksville, Maryland   Posted by bigdude  -  08/22/2008 10:36 AM Hey I got it! Just cross a couple of plug wires and you will get the sound you want and no performance, which sounds like what you are looking for???? resident know it all [ View ] [ Email ] [ Blogs ] [ Car Ads ] Three Rivers, Michigan Charter Member since January 2004   Posted by da34guy  -  08/22/2008 10:43 AM Frank- Go back to my post on 8/15 It's a tried and true combonation. Definatly gives ya the Lumpty lump, sorts like an old 30-30 Duntov Only a little more lump. Stop confusing yourself. Don [ View ] [ Email ] [ Blogs ] [ Car Ads ] Prescott, Arizona Charter Member since October 2001   Posted by boop coupe  -  08/22/2008 10:51 AM Hey "34" , whats a 2 dgree button? Are you saying you used the extreme energy cam & lifters with all else stock? Frank Jones [ View ] [ Email ] [ Blogs ] [ Car Ads ] clarksville, Maryland   Posted by da34guy  -  08/22/2008 11:22 AM Yep, when ya install the cam, just set it up 2 degrees over and yer done. stock lifters. pushrods,rockers,springs.. Talk to any "Real" engine builder and ask him how many he's done this way and he'll tell ya "Hundreds!!!" My Builder has been doin this for over 25 years, never had a problem Ask 29 Robert on this site what my Blue roadster sounds like. It'll even set off car alarms idling. Good luck Don [ View ] [ Email ] [ Blogs ] [ Car Ads ] Prescott, Arizona Charter Member since October 2001   Posted by boop coupe  -  08/22/2008 12:19 PM Thanks for the encouragement Don. That would make life easier. Got the clear on the motor last nite. Looks pretty sharp. Ready to get the cam in and all the bolt-ons ...put her back in the car. Frank Jones [ View ] [ Email ] [ Blogs ] [ Car Ads ] clarksville, Maryland

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