New guy from U.K. first build help!!!

[Bago]

Hello Lads/Lassie's

My name is Ian and i'm based in the U.K.

My car is a '67 RHD Canadian Pontiac Parisienne currently still running its original 283 mouse and TH350 Trans.

I'm looking upgrade the powertrain.

In the workshop, on the engine stand, I currently have a 454 big block freshly bored out .30 over, a high rise iron manifold (Chevy), High comp iron oval port heads, new pistons, gasket set, lifters (flat, but might swap to roller), freshly reground and balanced crank, etc etc.

Here's the thing, I want this motor to look stock (ish), i.e. hence the iron manifold etc, but to cam it with a really nasty idle, to sound really pissed off, whilst still being reasonably drivable on the street. I'm sure you guys have heard it all a million times before (**rolls eyes!!

I'm currently looking at a Thumpr™, 279TH7
High Performance Street, Choppy/Thumping Idle cam and wondered what set up i.e carb (was looking at q-jets today), etc, etc to run with it.

Your advice, comments, jokes, experience, are all very much welcome,

I look forward to hearing from you,

Kind regards
Ian

[falconvan]

Welcome! Isn't the Canadian Pontiac a re-badged Chevelle? Sounds like a cool project; cant go wrong with a 454.

[34_40]

Welcome Aboard from Massachusetts.

Around here we call the Thumper cams / POSER cams.. why not select a cam that actually builds power rather than a cam that promises... but never delivers.

It's your car / build / choice of course, let us know which way you go.

[techinspector1]

You want a phony idle so it sounds like a digger motor, but you want to use an iron intake manifold so that the motor looks stock????? You're not making any sense. I think you're very confused.

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[Bago]

thanks man! She's essentially an Impala with a Pontiac shell!
454 is great, but need help on way to go with it!!

[Bago]

Yes indeed, that is why I am asking for help bud. If I didn't need it, I wouldn't be here now would I?
I'm a roofer, not an engine builder. Cars are my hobby, and as I said, this is the first time I've done this.
Car doesn't need massive power, respectable power is fine, and yes, a 'phoney' idle is fine if it sounds like what I'm after! However, if it's not possible, then tell me the best combo for rough idle and street drivability please.

[Capecreations21]

The thumper cam certainly will give you the "sound" you're looking for but as far as street ability it is a hassle in traffic or any kinda red light, the carbs and motor are essentially starving for air while you are just sitting there because the overlap in the cam is larger than the air and fuel mixture actually being taken in.

[techinspector1]

OK Bago, I'll try to help.
Race car cams idle roughly because when the motor is idling, the cam is BELOW its operating range. Stock cams idle smoothly because at idle, the cam is WITHIN its operating range. The operating range of a stock cam is idle to 4200 rpm's. The operating range of a hot rod cam is 2500 to 6000, for instance. So, when you try to idle the cam under 2500, the cam is out of its operating range. Same thing happens when you try to use a hot rod cam with an overdrive transmission. The motor is cruising along at 1800 rpm's, while the cam was designed to operate at a minimum of 2500, for instance. What happens is that the owner gets worse fuel mileage than he did with the stock 3-speed transmission, because the cam is being asked to operate effectively below its bottom operating range limit, which it cannot do. The first thing you have to learn about cams is that they are not a stand-alone part. They need to be orchestrated with all other parts of the motor as well as the torque converter, transmission, differential gears and tire sizes. The main thing that they have to be coordinated with is the static compression ratio.
http://www.crankshaftcoalition.com/w..._compatibility

Are there young fellows who will use a cam like you are suggesting in order to make people think he has a race motor between the fenders? YES
Is there always a contingent of old fellows who will call these young fellows "posers" and laugh at them? YES.
Is it possible to build a motor that idles rather smoothly, but will blow the doors off a poser vehicle and make the poser look foolish? YES.

The ball is in your court. Do you want to be a poser with a choppy idle and a slow car or do you want our help in building a killer motor, no matter the idle?
Hot rodding not only means building a killer motor, it means putting the car on a diet also. Are you willing to remove parts of the car which do not contribute to the performance of the car, like heavy bumpers and brackets and replace them with fiberglas units? Are you willing to pull all the carpet and insulation out of the floor of the interior? How about the back seat? Would you move the battery to the trunk, over the right rear tire to get better traction? Are you willing to install a posi-traction device in the differential and change the rear gears to something more performance oriented, like a 3.83:1 or 4.11:1 ring and pinion?
Did you want to keep the stock displacement of the 454 or did you want to bore and stroke it to get more cubic inches? What's your budget?
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