honest opinions needed here

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trudysduster

trudysduster

FABO Gold Member
FABO Gold Member
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I have been doing a lot of research here on this cam and heads I am about to put in the Dart Sport and it seems like there is going to have to be some give and take on this. its a 360 with a 4 speed. hell you guys know the car by now. Tyler wants this car to beat my Duster and there is no way its going to be done like it is. He wants it to sound like mine and its not going to happen. Everytime I start it he just stands there and says that's sounds nice. Problem is he wants to keep the power brakes and stuff and If I put the components in to do what he wants, he is going to have to spend a lot more money than he wants to do it. So here is what I have come up with. I want to know if this is the best way to go here. I believe I have picked the biggest cam I can to have enough vacuum to not hamper the vacuum for the power brakes and still give him a good sounding, running ride.

K20-223-3 Comp cam Xtreme energy kit-XE268H
7958-16 pushrods
double roller timing chain and gears
going to have the 340 X heads done
stay with the 750 CFM carb

I was debateing on going with the MP-4452992AE cam but decided to stay with the Comp. cam. I have been on the phone with Comp. cams, Jegs, Summit. I wanted to stay with the factory rockers instead of adjustables. all 3 people I mentioned told me I could even running the Thumper cam with stock rocker arms I was going to put in but I would be running into a vacuum problem and had to get an electric pump. So let me know what you guys thing about this combo and if I can tweek this any without him spending a ton of money, let me know. This is strickly a street application and I am assuming probably something I don't want to know about when he isn't around me. Thanks,Bill
 
Have you looked at any of the howards cams? They have a cam series called the rattler similar to thumpr but not as radical. Here is a part # if you want to look up the specs. howards 718001-09 not as tight of lobe seperation so it should have better vacuum.
 
Considering your thoughts on this Bill, that combo is about as good as it gets, considering the criteria. Then there's Tyler's thoughts...lol.

Now days the XE268 is really the go to cam for a regulation SB street car. Years back it would have been the Magnum 280* or one of the many derivatives.

The XE will have a nice sound, still uses mild springs, and be very drivable. Will it take out your 440, I doubt it.....Just don't let him read this. :)
 
OldmanRick said:
Considering your thoughts on this Bill, that combo is about as good as it gets, considering the criteria. Then there's Tyler's thoughts...lol.

Now days the XE268 is really the go to cam for a regulation SB street car. Years back it would have been the Magnum 280* or one of the many derivatives.

The XE will have a nice sound, still uses mild springs, and be very drivable. Will it take out your 440, I doubt it.....Just don't let him read this. :)
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That 280 Comp cam ,is so much fun.lol.
 
I had the 268 in my 360 before I tore it apart fix a few things (going solid roller now). It was a pretty good cam, the idle was still pretty smooth but you could definitely tell something was there. It also made good power, that cam would work good with 3.55 gears or so as well.
 
well, the only thing I was concerned about was the vacuum for the brakes. Didn't want to spend a lot of time and money and be a concern when it was over. I don't have power brakes on my Duster but I am used to that. He drives a 05 Grand Prix as a daily and he hates my brakes so keeping power brakes is a must for his young self. I guess I will go with this. I talked with him last night and he is happy with it. I explained to him that sometimes it is give and take when it comes to things in life and let him make the call. Thanks for the response. It is the best I could come up with not knowing what I am doing. will get these parts in and just do it. Bill
 
moturbopar said:
Have you looked at any of the howards cams? They have a cam series called the rattler similar to thumpr but not as radical. Here is a part # if you want to look up the specs. howards 718001-09 not as tight of lobe seperation so it should have better vacuum.
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STAY AWAY from the thumpr cams. They are aweful.

To the OP, that looks like a nice cam and should have some decent street manners.
 
roccodart440 said:
STAY AWAY from the thumpr cams. They are aweful.

To the OP, that looks like a nice cam and should have some decent street manners.
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Awful? have you ever ran one? most people who talk smack about them have never run one and are just "following the crowd". Personally, mine ran pretty good. Made a nice flat torque curve and just over 350hp in a 318 with J heads. I actually liked it's power delivery so much that I'm putting it into a 318 for my drift project next year. (it's not an A-body)

But yes, due to the thumpr's overlap it isn't "ideal" for power brakes. Though can be done successfully.

OP. +1 vote for the 268. should be a good choice for a mild "daily driver" type build and make decent power too.
 
15/16 bore master cylinder for decent pedal feel, dump the power brakes, get some old adjustable 273 rockers, go flat tappet! just my .02$ :)
 
So, are you saying you want to put a small cam in your kids car so his small block won't beat up on your big block?...lol.
 
frosty_the_punk said:
Awful? have you ever ran one? most people who talk smack about them have never run one and are just "following the crowd". Personally, mine ran pretty good. Made a nice flat torque curve and just over 350hp in a 318 with J heads. I actually liked it's power delivery so much that I'm putting it into a 318 for my drift project next year. (it's not an A-body)
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Yes, I have . We put the mother thumper in my fathers current truck. It's a 10.5:1 454 with AFR heads. It's awful in every way.

Sure it sounds cool, try to idle around town or in traffic with it. Try running power brakes (even with a booster) and for as radical as the cam sounds it made 503hp. Whoopty do....
Torque came in late, hp ran out early.

Albeit he doesn't have enough convertor in the car. The carb is a Quickfuel and is set perfectly and the timing is spot on as well. Engine was dyno tuned and then idle reset in the car.

basically it's the same specs as my cam as far as lift and duration, same specs my engine for that matter (his heads are better)and makes pretty much the same HP. Mine idles like a kitten. I run a 950 proform. Dialed in by the same builder. 17/35 for timing




A body said:
15/16 bore master cylinder for decent pedal feel, dump the power brakes, get some old adjustable 273 rockers, go flat tappet! just my .02$ :)
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daredevil said:
Why not go nasty cam and use a vaccuum pump. You scared to let him smoke you?
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RMS set me up with a 7/8 master and manual brakes. Poor man's power brakes he called it. Love it. Feels and acts like power brakes.
 
I just ordered the 268 cam and lifter kit with all the needed parts to install this. it will be here tomorrow. I think it will be the best for his situation. Thanks for all the input. Bill
 
roccodart440 said:
Yes, I have . We put the mother thumper in my fathers current truck. It's a 10.5:1 454 with AFR heads. It's awful in every way.

Sure it sounds cool, try to idle around town or in traffic with it. Try running power brakes (even with a booster) and for as radical as the cam sounds it made 503hp. Whoopty do....
Torque came in late, hp ran out early.

Albeit he doesn't have enough convertor in the car. The carb is a Quickfuel and is set perfectly and the timing is spot on as well. Engine was dyno tuned and then idle reset in the car.

basically it's the same specs as my cam as far as lift and duration, same specs my engine for that matter (his heads are better)and makes pretty much the same HP. Mine idles like a kitten. I run a 950 proform. Dialed in by the same builder. 17/35 for timing
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Respectfully, the thumpr and the mutha thumpr are completely different grinds, a truck is not an A-body and a 454 chev is not a 360 chrysler and having "not enough converter" is usually pretty awful no matter what bumpstick you're running. (awfulness depends on how "not enough" we're talking)

I understand you were disappointed with the results of the combination, but I think the assumption that the entire blame for that disappointment lies in the camshaft alone and that as an extension of that, the entire range of thumpr camshafts are inherently "awful" is rather short sighted.

Especially when your basis of comparison is an entirely different brand of motor with nothing alike (your 440) and the only similarity being overall displacement.

Now on the other hand, if you have changed out the mutha thumpr on the old man's truck and done a comparative dyno comparison and/or quarter mile pass with a similarly priced flat tappet hydraulic cam that showed that the awfulness had gone and the power had (mostly) stayed or even improved, that would warrant your seemingly bad attitude towards that particular camshaft.

I've been disappointed before too and it definitely leaves a person bitter. That's pretty natural. but I try to avoid giving advice/opinions like "it's awful" unless I'm absolutely sure the product is flawed or unreliable in some nonredeemable way.

Maybe I'm just too hesitant to blatantly bad-mouth one specific part based on one bad result for which it may or may not be partially or completely responsible?
 
I know people that have used the thumpr and whiplash cams with very good results. They have to be used in the correct applications.

A 4 speed give some leeway in duration that can be run with vacuum concerns.
 
Power brakes are pointless in an a-body IMO I'll take my duster's manual discs over power setup any day. Pedal feel works like a poor man's ABS, so easy to modulate...
 
trudysduster said:
well, the only thing I was concerned about was the vacuum for the brakes. Didn't want to spend a lot of time and money and be a concern when it was over. I don't have power brakes on my Duster but I am used to that. He drives a 05 Grand Prix as a daily and he hates my brakes so keeping power brakes is a must for his young self. I guess I will go with this. I talked with him last night and he is happy with it. I explained to him that sometimes it is give and take when it comes to things in life and let him make the call. Thanks for the response. It is the best I could come up with not knowing what I am doing. will get these parts in and just do it. Bill
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Hey Bill, tell Tyler for me that since he's using his left leg more going 4 speed, he needs to go manual to exercise his right leg more. Otherwise his left leg will be bigger than his right. lmao
 
Richen the idle/off idle mix up a bit; will help the rumpity rump. Might want to invest in an inexpensive wideband O2 gauge.
 
frosty_the_punk said:
Respectfully, the thumpr and the mutha thumpr are completely different grinds, a truck is not an A-body and a 454 chev is not a 360 chrysler and having "not enough converter" is usually pretty awful no matter what bumpstick you're running. (awfulness depends on how "not enough" we're talking)
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I'm running a Comp Mutha thumpr Hyd. Roller cam in my 360 that has about 9.7:1 compression.

At first I kinda hated it, but after driving it awhile I'm actually starting to like it alot.
Power felt real good off the line, not super awesome but again this is mainly a high perf. street car. I'm able to squeal the tires a good distance and I have 3.23 gears and 26.5 inch diameter tires.

I think it'll even be better with a fresh Thermoquad and a 2500 stall converter (currently have 2000-2200 stall)

I don't have power brakes or power steering (don't really need it since these cars are fairly light)
 
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