Stock Buick 455

Currently running a stock 455 with eldobrock intake and holley sniper TH400 transmission, 3:42 gear. I was wanting to change the camshaft to something with a nice thump to it. I was looking at TA performance and seen the 284-88h cam that I don't have to change the valve springs and other stuff that comes with it. I love the sound of the Comp cam Thumper camshaft is there anyone running a thumper camshaft or a 284-88h camshaft or something close to the thumper. What are your pros and cons of the camshafts what would be the best camshaft for me to run on a stock engine.

 

James I was running a thumper cam in my old 72 455 build that was mostly stock. I loved the sound of it but those types of cams leave lots of power on the table. They sound awesome but run like dogs on the street unless you do other things to your setup. I put a TA 290 94H in my new build, don't know what it sounds like yet as the engine isn't finished but I've heard sound clips of it and have heard good feed back on it from guys on here. I think most guys will tell you to stay on the small/conservative side on cam choice with a low compression stock engine. Getting a 9.5" converter from JW here on the board will wake it up a bit and definitely compliment your 3.42 rear gearing. Lots of "cam threads" on here too

 

Valve to piston interference. You can change the tired valve springs and seals with a compressed air setup without removing the heads so your cam will rev the way it's supposed to.

 

referring to which camshaft

 

I have been looking at them on YouTube they sound pretty ok I just like the thumpers sound I know I have to do more work if I go that route… the convertor you are telling me about is that a stall for the set up I have now?

 

I put one in a stock motor, made the engine a turd, sounded good but that’s it

 

The thumper??

 

Don’t buy for sound. Call TA and ask what they recommend for what you’ll be driving. (Not what you hope to build, not what you hope to buy next). I thibk a stock built ‘70 will need something mildish, 225/235 at the most.
Patrick

 

Jim has the converter built to the specs of your build/car. I gave him all the specs of my current engine, rear gear ratio, tire size etc. I told him all the specs of the new engine I was building. He built me a converter to work with my current set up as well as to grow into my new build. Do a search on here there's tons of info on his custom converters. What car do you have? Besides the ones for the smaller A body cars he also makes "big car" 9.5" converters, which is what I have and man it really woke my car up even with that thumper cam I had in it.

 

Buy a camshaft based on power, not on idle misfiring.

 

Absolutely!
The right cam for your combo will run awesome and will sound however it sounds at idle, unless you just run your car/engine at idle 100% of the time.
At TNT years ago, a guy with a super lumpy cam and Flowmasters in his Chevy truck was in the next lane, I still had the TA 413 cam and Walker 17749 mufflers in my 350 GS, mine had a mild lope, nothing earth shaking for sure, I walked away from him EASILY, at the time I was only running low 14's

 

if you want just the sound its much cheaper and probably even a power gain if you just go 2.5- 3" exhaust straight to some Glasspacks.
I have that in my C10 with a stock 455

 

yes, went from nice idling engine to always adjusting idle and mixture to try and find a happy spot, i did not change the converter, that may have helped but sold the car as is....of course new guy loved it..lol

 

If your dead set on a comp cam.
I highly recommend this one.
https://www.compcams.com/xtreme-energy-230-236-hydraulic-flat-cam-for-buick-400-430-455.html
works fantastic in my car. Sounds snotty and runs great.
9 to 1 464. Small valve. Performer, Qjet now fixed and upgraded, running kick gas by Rob Ross.
Been 12.40@108 before upgraded carburetor.
Runs better than ever now. Good drivability and yes great power brakes.

 

FWIW this is the kit the PO of my car put in my old engine.
https://www.summitracing.com/parts/cca-k96-600-5

 

That's pretty much the duration of the 284-88H...223* In./230* Ex. and 0.460" lift with the stock 1.55 rocker arm ratio.

I used that cam when originally rebuilding the engine...0.020 overbore, 10:1 cr cast (poor choice) pistons (actual static cr was ~9:1), TA's shorty headers, and 2.5" exhaust. The 284-88H definitely made the Riv (with 3.42 posi) even more fun to drive! Later, after breaking the 40 year old xmsn, installing the pre-9.5" big car converter from JW helped too.

I thought it sounded badass, but to Larry's point, be sure to calculate the dynamic cr. When I replaced the small valve iron heads with TA's Stage I SE's aluminum heads, the increased compression put the dcr at the bleeding edge of pump gassability.

 

Aluminum heads can take more compression than iron with pump gas. You should be just fine.

 

Aluminum heads conduct the chamber heat out much faster than cast iron which lowers the chamber pressure, pressure is what drives the pistons down the cylinder bore. Smaller chambers have less surface area exposed to conduct chamber heat into the cooling system. Like a coated aluminum piston top helps insulate this heat escape path, more pressure, more push, more torque and horsepower. I've found in 455 Buicks about .75 to 1.0 point static Compression Ratio 'HP number comparison difference' depending on RPM between Aluminum and Cast Iron in actual running comparisons. Match your cam to the required dynamic compression ratio and scavenging effects. Everything matters a little bit in the final engine output one way or the other. Lots of little bits put a smile on your face.

 

FIFY.

Yup.