Author Topic: Removing pistons  (Read 7059 times)

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Offline smitty2

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Removing pistons
« on: February 17, 2006, 01:06:43 PM »
I got a "Great Deal" on a 61 chev 283.. The #3 cylinder has a large hole in it due to a valve bouncing around. My question is can I remove pistons from one side of the block, and how the heck do I balance everything? I read where the Larson - Cummins streamliner had rod caps bolted together for balance... It seemed to work for them.
 Anybody have any ideas?
Thanks...   Smitty

Offline Dave Cox

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Removing pistons
« Reply #1 on: February 17, 2006, 01:19:18 PM »
Easiest way to run without using #3 is to run 1,4,6,7. The assembly will run very well (pull 4 wires off your V8 and try it!). If you try to run one bank only (2,4,6,8), the engine will not fire evenly and try to jump out of it's mounts. Many 4 cylinder KB hemis have been run this way with spectacular results (over 300 on El Mirage, Mike Wesche). Running one bank will require a custom crankshaft ($$$$). Some early V8s used a "flat" crank (Hispano-Suiza, Peerless), they worked fine on one bank.

Run 1,4,6,7, cut the big ends off the rods you're not going to use and bolt them onto the crank. That'll space the rods correctly on the crank journals and reasonably balance the crank. Or for a few $$ have some rods made that are double width on the big end, it'll give you a better bearing!

Offline Sumner

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Removing pistons
« Reply #2 on: February 18, 2006, 12:39:12 PM »
   

This topic of running a V-8 in a different configuration has interested me as I was going to originally do this with a motor for my lakester before I switched to the motorcycle motor approach.

   

Some have had luck with this and others haven't.  As a result of this post I decided to make a page on my site with the information I have collected over the years.  Now bear in mind some of this info might not be accurate due to failing memory on my part  :cry: .

Instead of repeating it all you can go to the page I've created ( HERE ).

Ken if you read this please post or get in touch with me if you have more information or thoughts on this subject.  I don't know if Russ Eyers frequents this board, but I would also like to here more from him on this subject and want to thank him for spending his time with me on the salt with info about running a sbc on 4 cylinders.  I have his comments on the page on my site and he is responsible for the motor in the roadster pictured above.

Hope some of the information I have helps someone,

Sum

Offline John Burk

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Removing pistons
« Reply #3 on: February 19, 2006, 01:12:30 AM »
There are 2 kinds of imbalance . The harmless type that shakes the motor on the mounts like a Harley v-twin and the kind you can't feel but kills the main bearings like when the crank is balanced wrong . If you have the right weights clamped on the unused journals you can use any combination of cylinders . An even firing order (1-4-6-7) just feels better from the outside . On the 1st and last rod journal with just the big end of a rod  where the rod and piston was the guy who balances the crank would have to grind off a lot of the counter weight . The 2nd and 3rd gournals counterballance each other so it wouldn't matter there .  The clamp on weights need to weigh the same as the bob weights the balance shop used (the weight of the big end of the rod and I think half the weight of the small end and piston) .

Offline smitty2

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Removing pistons
« Reply #4 on: February 19, 2006, 01:23:53 PM »
Wow! I thought this would be easy :D Seeing as this was a "Freebie" engine I think I will bolt it to a pallet and experiment till it flies apart.
The v4 configuration sounds like the smartest (Cheapest) way. I had an old IHI Scout that had what I believe was a Pontiac v8 that was bandsawed down the center.. it even had plugs in the distributer cap so you could use a v8 cap. Wish I could find one of those beasts just to tear it apart and see how they did it.
 Those guys with the SBC/Flattie have got the coolist looking engine I've seen in a long time! What a neat idea.
 Thanks for the help guys, and if anyone has anymore ideas... I'm really open for suggestions (within reason of course :shock: )

Smitty

terry russell

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Removing pistons
« Reply #5 on: March 27, 2006, 08:47:09 AM »
would this result in running in a lower class under scta rules ? C to D

dwarner

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Removing pistons
« Reply #6 on: March 27, 2006, 09:22:16 AM »
What the displacement measures is the class you run in.

Bore x Bore x .7854 x Stroke X # of cyl = displacement

DW

terry russell

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Removing pistons
« Reply #7 on: March 27, 2006, 02:27:07 PM »
so do dead cyls. count ? My first post was after working all night. It was just an idea on making a car fit in more class's thanks

Offline Dave Cox

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Removing pistons
« Reply #8 on: March 27, 2006, 04:50:48 PM »
Nope, if there's no pistons those don't count.

Dave

Offline russ jensen

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bal 283
« Reply #9 on: March 27, 2006, 08:08:29 PM »
8) If it;s  the 2n'd cyl back thats bad . take everything thats hookeed to the second and third crank jrl and throw away :plug  the oil holes that fed rods and just run the front 2 cyl and back 2 cyl, speeking of bal cranks,301 pont has a real weird looking crank , only counter wts  are on each end { only 2}  balanced buddies ferrie v-8 w/ flat crank like 4 cyl- couldn't beleive they used such a deal but had motor mts size of basketballs, {cross fire cranks shake bad} crower had pics in cat of such a mess, thought I might as well try, had one started when old racer told me to call arlin vanke  before I wasted to much effort=  I said , hear you ran crosfire cranks in your hemi , he said what are you going to use this crank in: why dirt burner, he told me that I wouldn't have time to stop in every corner and bolt everything back on eng. Did a big leroy v-8 w/ one of these cranks {was a 4 cylmotor & other 4 - air compressor, guy wanted me to bal as all tin on trk was cracking, sorry no hope here.
speed is expensive-how fast do you want to go?-to soon old & to late smart.

Offline Rex Schimmer

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Flat cranks in V8s
« Reply #10 on: March 27, 2006, 10:38:16 PM »
Back in the mid 80s I was a fixture at the Saturday night Ascot sprint car races and a couple of guys got together and built a big Keith Black hemi with a flat crank. In those days there was not a cu. in. limit at Ascot, if you could get it between the frame rails and find someone to drive it, it was legal. Anyway this KB V8 had that twin rice burner 4 sound that flat cranks make and was really quick betweent the corners, they were still working on making it actually go around the corners when they drove her into turn 3. lifted to get the nose to turn down and when they picked up the throttle out came the crank and 7 rods and pistons. Looked alot like the Magic Muffler Fiat at Lions back in the 60s!! Never did see them again.

Rex
Rex

Not much matters and the rest doesn't matter at all.

Offline russ jensen

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sprinter
« Reply #11 on: March 28, 2006, 12:42:21 AM »
:lol: What did it do ?vibrate all main bolts loose?  The big leroy had everything saftey wired and it was low rpm, buddies  farrie  had a real short strk  so I guess that is how they get by.  @ time I called dave crower & quized him about what vanke told me & he got real defensive and next cat it was gone, still have crank around somewere, once I got some gm big blk blank cranks and figured out how they were forged and then twisted, I just untwisted a 454 crank.  ON stock car had set of headers that took 2 cyls from one side and dumped w/ 2 from other side, added a good set of megaphones and got the flat crank sound, and when a big block was turning 7500 it sounded like 10. megs worked so good started to crack all al sheeting in car.by the way how did you come out once the crank left ie no power????  bad wreck or set down nice & easy??
speed is expensive-how fast do you want to go?-to soon old & to late smart.

Offline Rex Schimmer

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Untwisted the crank????
« Reply #12 on: March 28, 2006, 04:56:10 PM »
Russ,
You farm boys sure don't know enough not to do something!!! How in the hell did you untwist a 454 crank??? I really would like to see your shop you guys are sure doing some interesting things!!!!

The guy with the KB with a flat crank did not crash, the car jumped over the crank/rod assembly that was trying to go underground and just kind of rolled to a stop! No go power i.e. no go!!

Rex :wink:
Rex

Not much matters and the rest doesn't matter at all.

Offline russ jensen

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twist crank
« Reply #13 on: March 29, 2006, 12:12:23 AM »
:lol: jUST LIKE GM DID IN FIRST PLACE, heat it up till its ready to drip and twist it back like it was forged, couldn't beleive this is how their made but when I got blanks you can see the forging  parting lines where they get yanked 90 dg.
speed is expensive-how fast do you want to go?-to soon old & to late smart.

Offline Rex Schimmer

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Twisting cranks at GM:
« Reply #14 on: March 29, 2006, 10:46:00 AM »
Russ,
When they do them at GM they have a big advantage, as the lump is already hot. As I remember it they forge the crank flat, so there are a series of dies that take the forge billet and form it into the basic crank shape and it is "flat" then the last die or dies actually are formed to offset the rod throws to the 90 degree angle. So they already have a hot lump to form. I wonder if you could get the forged blank before it is twisted?? Now you would have a flat forged crank. Not that I think that flat cranks are the hot ticket in V8s but it might be cheeper than a billet crank or reheating and making it flat like you did. Plus you would have lots of stock to machine, what did you do with the crank that you "flattened" as far as making all of the mains and crank throws straight to each other? Big time undersize grinding?

All of the new Formula One V8s have flat cranks and as I understand this basic configuration has an inherent vibration that they can't get rid of and it just get worse as the rpms go up. Must be a pretty good shake at 20,000 rpm!

Rex
Rex

Not much matters and the rest doesn't matter at all.