180° crank for Pontiac engines?

[Ripper]

Does anybody know if there are 180° cranks for pontiac engines available?

I have a 400 engine and it would be great to switch the current crank for a 180° instead. the other alternative is to build 180° headers which would be possible since I have a low profile dry sump oil pan...


Any ideas about the crank?

If anyone wonders, it's for the sound I want it! People would really :hmm: wondering what kind of engine the car has when they hear it...

[rohrt]

WOW! I learn somthing new every day. Never heard of such a thing. I'm sure it would have to be Custom$$$

[Johnny Blaze]

That would be a lot of work, cost and trouble, just to get a sound.

[elcamino80]

Ive never heard of such a thing before either!

Can you Anders or anybody else explain what it exactly is and what it changes?

Yeah I know, I know very little about these things but I try to learn...

[Lowend]

Scat will do a billet for you... I'd imagine that Crower would too but be prepared to pay $$$$$

[Goatman]

Crower will make them (I owned one at one point), but you've got to order a bunch, then be prepoared to wait........


As for this topic, let me get my waders.......

[Ripper]

That would be a lot of work, cost and trouble, just to get a sound.No, actually not just to get a sound. Since I'm thinking of buying a new crank anyway. I was just wondering if there were any 180cranks on the market since it was interesting to know if if there was a big difference in price.



Scat will do a billet for you... I'd imagine that Crower would too but be prepared to pay $$$$$ah, thanks! I'll check with Scat!



As for this topic, let me get my waders.......Not sure I got that... :hmm:

[LowBuckX]

IM wrong

[Ripper]

Ive never heard of such a thing before either!

Can you Anders or anybody else explain what it exactly is and what it changes?

Yeah I know, I know very little about these things but I try to learn...


Well, not sure that I dare to explain myself, so here's some links that you can read about it;


Similarly, while production V8 engines use 4 crank throws spaced 90 degrees apart, racing engines often use a "flat" crankshaft with throws spaced 180 degrees apart, accounting for the higher pitched, smoother sound of IRL engines compared to NASCAR engines, for example. In engines other than the flat configuration, it is necessary to provide counterweights for the reciprocating mass of each piston and connecting rod; http://en.wikipedia.org/wiki/Crankshaft


There are two types of V8s which differ by crankshaft. The V-angle is always 90°. The two types are called cross-plane (crank pins at a 90° angle) and flat-plane (crank pins at 180°). V8 engines have the advantage of not being in need of split crank pins in order to avoid vibrations between cylinder banks.
With a cross-plane V8, however, the last cylinder is not in the same position as the first, so there is end-to-end vibration again. That can be solved by adding counterweights to the crankshaft which cancel the forced created by the pistons. That is possible only in a V-engine with a V-angle of 90° and without splitted crank pins. These counterweights, fitted to an inline engine, would move to the side when the piston moves up or down and therefore generate additional vibration. But in a 90° V-engine there are pistons on the same crank pin which move exactly into the opposite directions of the counterweights (because of the bank angle) and their forces can be cancelled. Cross-plane V8s are therefore running quite smooth but because of the heavier crankshaft they are not as revvy.
Flat-plane V8 engines do not have those problems. They are also more responsive because of less rotational inertia. That increases maximum rpm and top-end power. In addition the crank case can be smaller which lowers the center of gravity.
But why are the flat-plane engines used in sports cars only if there are so many advantages? That's because of the crankshaft itself, the disadvantage of the flat-plane type. As you can see, the arrangement of crank pins is identical to a four cylinder engine which means there are also vibrations, only stronger, as basically two inline-four engines are running simultaneously. In sports cars those vibrations are reduced by using very lightweight pistons and connecting rods. That is of course expensive and because ride quality isn't too important either, the rough characteristics (compared to a cross-plane) are tolerated. Because of the crankshaft, the sound of such an engine is the one of two four cylinder engines. A (typical american) cross-plane burbling cannot be achieved. http://www.e31.net/engines_e.html

And here's a picture;
https://static1.pt-content.com/images/noimg.gif

Here's a standard 90° crank;
https://static1.pt-content.com/images/pt/2007/03/V8CrossFront-1.jpg

and here's a 180° version;
https://static1.pt-content.com/images/pt/2007/03/V8FlatFront-1.jpg

[LowBuckX]

Do you realy want your car to sound like 2- 4 cylinders fighting it out .
http://64.233.167.104/search?q=cache:hEhWWjeSZZcJ:home.clara.net/captain.norton/cnn2sec14.html+180+degree+crank&hl=en&ct=clnk&cd=2&gl=us
copied from

The 180 degree crank has perfect primary balance but NOT secondary balance,as shown in the table. The 90 degree crank , on the other hand is better than the 360 degree crank, but far inferior to the 180 degree crank in matters of balance. The fact that the power pulses in any but the 360 crank are not evenly distributed means that the torque is irregular and torsional vibrations may be set out in the crank, unless it is stiffer and heavier than the 360 crank.This may have been the reason that convinced Edward Turner to adopt the 360 crank, in spite of its inherent unbalance problems. The secondary imbalance cannot be eliminated except with a balance shaft rotating at twice the crank speed, so that the performance of the 180 crank without the balancing shaft cannot be improved. The question remains what would be the performance of the 90 degree crank if the piston,etc. is partially counterweighted at the crank. Assuming a "balance factor" of 2/3, a figure widely used by many manufacturers, the vertical and horizontal force as a function of the crank angle for the 90 crank have been computed and are shown in the next table, alongside the vertical force for an UNBALANCED 180 crank (there is no horizontal force for this crank).

[Goatman]

I can't even imagine why you would want to do something like that....


The Crower crank I had was gundrilled, knife edged, and had every trick in the book done to it, all coming in at around $3400....


What you want I bet will be at least double that, with no discernable results, unless you're planning on revving it to 9,000 rpm. Which, on a Pontiac, is futile...

[Johnny Blaze]

No, actually not just to get a sound. Since I'm thinking of buying a new crank anyway. I was just wondering if there were any 180cranks on the market since it was interesting to know if if there was a big difference in price.


ah, thanks! I'll check with Scat!


Not sure I got that... :hmm:

I was saying that to the original poster, who stated he wanted it for the sound.

[Ripper]

I can't even imagine why you would want to do something like that....
And I don't understand why people put 22" wheels on their cars...

Last time I looked in my garage, there was a -74 Firebird which was mine. I bought it, I own it. That means that I should be free to do whatever mods that I feel like, right? https://static1.pt-content.com/images/pt/2007/03/wink-1.gif

I was just asking if there were any 180 cranks available for the Pontiac engine...

[rohrt]

Anything different is cool! I for one would love to see it done.

So $3400 for a crank, What about a Cam?

[67bird]

Ripper,
Scat will do an ultra light crank (conventional design) for about $3000.00 these come in at about 64lbs. These are billet cranks. I would assume for the money that Bryant, scat, or moldex would make you just about anything. I can tell you that racers like John Langer and Scott Rex are running their engines in the neighborhood of over 8000 rpm with such items (conventional design). The latest alternative would be a forged crank. All pontiac has these on sale right now for about $700.00 depending on pin diameter and stroke. They are curently only making 3.00 crank pin diameters. A 3.25 inch crank pin (for 428/455 blocks) is coming out soon. These weigh in at about 74 lbs. They are by far the best bang for the buck. I applaud you in wanting something different. I don't want to steer you from that. I used to be into Oldsmobiles and got the same reaction. Now I am into Pontiacs, and it hasn't changed much.

[Scott Parkhurst]

Moldex did a custom Pontiac crank for me. I worked through Butler Performance to get exactly what I wanted/needed.

I am more than satisfied with the part, and the Butlers are great to work with. They'll also be able to answer your questions about the crank and any other Pontiac engineering inquiries you may have. I highly recommend them to you based on my personal experience working with them.

Moldex does awesome work.

You didn't ask for an opinion on a 180-degree crank for a traditional Pontiac V-8, so I will respectfully not share one...but ask the Butlers about it when you call.

~SP~

[astroracer]

but ask the Butlers about it when you call.

And then let us know what they say...
Mark

[Goatman]

Exactly what I've already said....... Know the Butler's, as the other racers mentioned on this thread. If there was an advantage doing this mod, they'd already have done it...

[pdq67]

Heck, if you want to be different, then hunt up a, (I think??), low-deck, 303 engine that they made back then to compete against the 302 Z-28 engine.

Try here for a decent read..

http://en.wikipedia.org/wiki/Pontiac_V8_engine

pdq67

[Ripper]

Heck, if you want to be different, then hunt up a, (I think??), low-deck, 303 engine that they made back then to compete against the 302 Z-28 engine.

Try here for a decent read..

http://en.wikipedia.org/wiki/Pontiac_V8_engine

pdq67

Yeah, that would be cool! however, I don't think I would dare to use it... :scared:

[73ta]

Ripper'
1. Me neither
2. Yes, but limited to money & availability
3. No