I contacted Comp Cams for advise on a cam change I'm going to make, and they recommended one of their Thumpr Hydraulic Flat Tappet Cams for the set up I have. I'm looking for some pro or con opinions on the Hydraulic Flat Tappet Thumpr Cams.
Well, I just put the mildest Thumper in a 427 Vette I built, and it was a bit much for me thru side headers. Definately had a "thump" !! It was a hydraulic roller cam, and when the cheap Chinese lifters I bought ( and I know better - another story) self destructed and took out the cam, I went to a hydraulic flat tappet Extreme Energy cam - which was more to my liking (also a LOT less expensive). You pay a lot for the Thumper marketing. But if you really want a nasty idle (almost beyond "cool" nasty for me ) - go for it !!
I used run all comp cams. Recently I have found out their cam blanks come from overseas and their quality has been kinda hit and miss. As far as the Thumpr cams, I think they grind the cams at a wide LSA. You suffer a little performance wise for the "thump" idle. If its just a cruiser, i say go for it. From a performance stand point, i would say no. if you are building an engine to run hard, i would go with a Lunati diego
Paying more money for your engine to run unneccesarily like shit? All while gaining the added benefit of having a MUCH bigger bark than your actual bite... I'd pass...
Isn't that a funny coincidence, they feel the right cam for your engine is their newest and most heavily promoted line?
Or if you have a manual choke pull it out till it sounds nasty,then when you want it to run decent push it back in Can't see paying that much for "sounding BAD" and losing overall performance.
I understand the wider lobe angle calms down a radical cam. I ran a fairly big - for the street - wide angle cam in my BB Buick engine and it sounded fairly calm when it warmed up. Kinda funny to see some of these lumpty-bumpty cams idle through the driveway and some kid running a darned near stock engine will blow the doors off them. Get yourself one of them "RV" cams that some are so proud of . . . whatever the hell they are....
Whoops. I misspoke. They grind their Thumprs at a narrower LCA and their intake center line is funky too. Go with Iskendarian or Lunati.
I don't think fake patina can be compared to this cam. Fake patina is for douchebag posers who can't find real steel. The purpose of this cam is to get the chop of a monster cam without having to run a 4500+ stall converter. I think it's total BS that they are charging more for a cam they had already developed for road racing, but relabeled "Thumper". The cam isn't total garbage, but it is true that Comp has gone down the shitters the last couple of years. Lots of my friends have gotten flat cams from them. I think they are trying to sell you a cam they have a shit-ton of. I'll bet they were banking on this being THE cam to go to. HOWEVER, it's your ride. If you like the way they sound, I say go for it!! You can here them on youtube Here you go http://www.youtube.com/watch?v=a59HsQyib7A
OT, but when looking for the thumper vid, I came across this jewel. The motor idling sounds exactly like the opening of "Hot for Teacher"!! http://www.youtube.com/watch?v=iuyIgo06Liw
I did see a cam comparison in Hot Rod Mag. or Super Chevy and the Thumper series dynoed with better average horsepower than the same comp extreme series cam and the other similar cams they were up against. I thought it showed they weren't just for show when I read the dyno results. The other things mentioned about the promotion of the cam are probably true too, but I don't think they are doing anything malicous. I like Comp Cams. I have them in two engines and a Summit cam in another. Have you checked out the Summit cams? They have super good deals on hydraulic flat tappet cams. What are you trying to accomplish with it or did I miss that?
I was interested in this cam as well. I wanted to have the radical idle. You guys are saying that it hurts the performance. Can you elborate on that a little? How mcuh is it going to hurt it? The main reason why I liked the idea of the Thumpr cam was the radical sounding idle wihtout having to run a large stall. I need all the power to come right off of idle. It was going into a 2100lb car with a 2.79 rear gear and 30" tall tires. So obviously I need the power down low. Any thoughts?
I was referring to high performance track type performance. Street driving I think you will be fine. As far as drag racing goes, there are better cams out there. I am going the opposite route. I wanted a fairly smooth idle that makes a shit ton of power, kinda sleeper mode. So I went with a Lunati roller cam
I am not a fan of Comp cams.... I try and stick with Isky for 90% of my stuff, they'll custom grind you what you want. I've got a crower in my mustang, no probs and it runs great, I've used Engle as well. Maybe because their is so many comp cams out there, it skews the datat, but I've seen many go flat, but that's a whole different story all in itself.. oil etc...
It's not a massive thing, and I'd like to see the comparison above, because I've not read it, nor was I aware of the road racing heritage. I will do more research now, but, the marketing makes it sound as if it is aimed at those who just really love the sound of poorly timed valvetrain events, but don't want the rest of the performance equipment needed to take advantage of the high-end... without a higher-stall converter, you can't take advantage of the "hit" when up in the rpm range where the cam is making power. From what I've heard, it just sounded like an inefficient cam, that would bleed-off cylinder pressure, and waste fuel...The tighter lobe seperation angle I was not aware of....Should have investigated more... But...they ARE marketing them in the "sound like a race car, without actually having to be fast" fashion, so...you know. As far as the 2100 lb. car needing all the power to come off the line, it should be fairly easy, really...its not much weight to initially get moving. You SURELY don't need a race-only converter to get a good launch, but why the desire to keep the 2.79 gear with a 30" tire? Thats the launch killer...
I really don't understand how you can have huge-cam idle chop yet avoid a high stall converter. Half the purpose of a high stall is to allow an engine with poor idle quality to idle.....it reduces the transmission's drag at idle. The other half of a high stall is to put the engine into it's powerband. If you aren't power hungry, save your money. Set the idle speed to 450 and set your tach redline to 8500 in case somebody looks inside the car.
Don't use Comp Cams, especially a hydraulic flat tappet, which you will have to break in. There quality control has gone to shit. The old timer sitting in the cube in front of me wiped out two cams in a 454 BBC. He's been doing this stuff 40 years so he knows what he's doing and I had warned him about the zink being removed from the oil so he was using ZDDPlus. I went over and checked it out on the second one and he did everything rite. Comp wouldnt warranty the first one as they said he assembled the engine in the fall and didnt start it until the spring and the assmebly lube must have washed off. The second one the gave him his money back on just the cam after he sent it in and they found the hardness to be wrong. This was on a newly rebuilt engine which had to taken apart and cleaned of an debris. The third one was an ISKY, same break in procedure he used on the first two and guess what, it runs like a champ and he's been cruising with it all summer long. I use to use Comp Cams and I never personnaly had a problem but after seeing the above issues first hand I'll never buy anything from Comp Cams again. On the other had Littleman ran the Hydraulic Roller version of the Big Mutha Thumpr in his truck and got it to go 10:89. So yea it sounded nasty but it ran the numbers too. He went to a solid roller since then. Gus
One simple reason, it is what I have and freeway friendly. I do a fair amount of freeway driving in it and with that combo I am usually running 2,500-2,800 rpms. So it makes driving the freeway easier. I wuold gladly move to a 3.0 or a 3.20 or something like that if I had the money to buy new gears and a posi. I was really lookign for something that runs good and has a radical sounding idle. I am not draggin the car nor racing it at all but like the sound. I figured 10:1 compression, 2.02/1.6 World Performance S/R heads and the small Thumpr should give me about 315 horse or so. Which should be plenty to get the 2400lbs (with me) moving just fine. I know there are lots of easy ways to get a little over 300hp out of a SBC. But I thought the Thumpr cam through open lakes headers would sound great. The short duration and smal LSA would give a narrow por band down low in the RPM range and the overlap would bleed off some of the compressiona nd allow premium pump gas. Any other suggestions on a cam or corrections to my assumptions?
hahaha thats funny!! RPU My first engine i built was a 383 stroker. It has a 280 magnum hydraulic Comp Cam in it. The compression was 9.1 to 1, roller rockers and ported and polished GM cast iron heads. On the dyno it made 387 hp and 391 ft lbs of torque. all on 87 pump gas! The idle was rough but not choppy. it sounded good and performed well. Had it in a 56 chevy with a stock converter and 3:36 gears out back. that thing hauled ass. I think that engine combo you got there will make over 315 hp.
Look at the dyno shootout done by hot rod= it will show a very good comparison between compcams. The thumper actually performs very well, small thumper that is. Only problem is there were no other brands compared. It was actually developed for road racing , they seem to work better in a manual trans. As far as bbc flat tappet cams going flat are fairly common.most builders wont use anything but a roller in bbc because of that
If I can ask would this apply to stock running ride My 250 six in my ford idels ruff no matter what I do. new carb dist.tune up could the converter be bad ? oh its a c-4 as soon as its moving it fine as frog hair !
Guys... I have one in my 57, and it works great. Motor is a mild 383, with a 200r4 tranny...stock converter, 3.70 gears. It is the smallest roller of the thumpr line. lots of torque, good power, excellent drivability, very nasty idle...definite head turner. The tight LSA really helps "seat of the pants" feel. I thought the cam was a gimmick as well, but thought I would try it. For a driver, This is a great cam. Just my 2 cents... sam
I appreciate all the input. The fact is I don't really care about the sound I'm only interested in a performance upgrade, the Thumpr was just the cam they recommended when I gave them the specs on my setup. From some of the opinions I've heard I may have to reconsider going with a comp cam. I have a 3700 lb. 55 Chevy. with a sb 350. It has a set of cast iron Vortec heads W/roller rockers, an Air Gap dual plane intake, and a Holley 670 carb. It has a turbo 350 trans, a 3000 stall conv., and a 3.90 rear. I know that a 2500 stall would probably be better but I got the trans and conv. from my brother-in-law for free so it was an offer I couldn't refuse. When I upgraded to the Vortec heads and the Air Gap intake I didn't upgrade the .460 lift cam and because of that I'm not getting the performance at the track that I was hoping for. I drive my car to the car shows and cruise nights and also Bracket race on Friday nights. I wanted my car to run in the 13's but the best it will do is 14.40. I wanted to upgrade my cam, so I contacted Comp Cams for advise on which cam would give me more performance on the track and wouldn't hurt It's streetability. The Comp Cam tech recommended their .479/.465 Thumpr or the .480/.480 lift Magnum cam. Like I said, I'm not really concerned how it sounds, I just want it to perform. Since most of the input about the Comp Cams has been negative I'll have to think about going with a different make.
i realize all these people are boasting an opinion...... well i have an educated opinion for ya...... i built a 350 4 bolt main for my A sedan a few months back.....bottum of the line Thumper cam..... bored 60 over, dome top pistons, 202 camel humps, heavy duty springs, heads and intake are both ported and polished, double roller chain (advanced 4 degrees)....... im running lake style headers that are capped and then run a straight pipe out to the rear of the car.... it has a set of boloney tubes on the ends of the straight pipes.... inside the boloneys i have built a neat little set of noise reducers (alot like the inside of a flowmaster)......... anyways the car is running 2.7something gears with 33" tall tires and a 2200 stall .......... i dropped this SBC in the sedan and wow, what a major difference it was compared to the stock 350 with mild cam it had in it before........it is super loud, super thumpy, and brute horsepower from a stand still like no one could even imagine..........even with the high gears and the tall tires....... Leaving a red light and just pulling the throttle wide open will cause it to strictly sit in its tracks and boil the tires til the high end of second gear....... so yah i speak kinda high of the above mentioned cam
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