Hot Rods 283 piston choices

I need some experienced old school guys to help out here. What is the realistic RPM limit on 283 Fuelie pistons before I should get some customs made. Block, crank and rods will be all set up and quality to handle it. I'll be running a small solid flat cam of modern design so I'm not looking to exceed what the 097 cam would do rpm wise but just make better power. Yes I know the valve train WILL have proper geometry and springs to work well. I just don't want the pistons to be the weak link if it gets spun to 6800-7000 range.

 

Good set of forged pistons.

 

What heads?

 

Kind of a generic answer. I'm basing my choice on piston speed and hopefully experiences supplied by people that have run 283's. Generally accepted cutoff for cast pistons is 3500 fps mean velocity. A 3" stroke reaches that at 7k. A 3.5" stroke about 1000 rpm sooner. I am working with a competent machinist with 5 decades experience with the oval track crowd and I'm a airframe/powerplant mechanic with past experience on Cosworth Indy engines. "Good" forged pistons are un-available without commissioning a set of customs. Trying to use up bits I have laying about to reduce clutter.

 

The heads are '462 castings which should work well with the fuelie dome piston. Plenty of room to adjust the dynamic compression to work on pump gas. Again, just trying to use up bits I have laying about. If I go to custom pistons then I'll not be able to resist going to an even better rod than I already have. That'll lead to thinking I need more cam to justify the pistons and rods. Then I'll be forced to spend hours grinding the heads to make best use of the cam...... endless.

 

Welcome to the world of hotrodding. Lippy

 

As of a few years ago, somebody (Mahle I think?) still made good quality pistons for a 283, but they weren't cheap. I believe I was quoted $900 for the set.

Devin

 

Wow,,,I’ve never heard cast pistons rated on Rpm before .
I always thought it was power rated, ,,,,torque,,,hp .
283 fuelie pistons were pretty good pistons .
To be honest,,,,I’ve never had a piston failure,,,,,and I have taken stock cast pistons,,,,,a lot higher than 6000 before .
But,,,I’ve never had a rod failure either,,,,,and some have,,,,,maybe I was just lucky .

Tommy

 

50 years ago my partner and I raced a 283 with what we called fuelie pistons. They were forged
TRW pistons. The pistons were never a problem but the rods were. We shifted at 8000 and went through the traps at 7200.

 

I can't see where you said if this will be a street or race engine and if it will be stock bore or over size. Many street 283s saw 6200 to 6300 routinely without issue with factory parts. I ran several 301s in the "70s with nothing special forged pistons that saw 7000 to 7200 on a regular basis. I went through mega gallons of Sunoco 260 and never had an engine failure. I assume that if you are considering having custom pistons made your application must be non-street as I don't see that you need them for an average hot rod engine.

 

The design and material of the piston will limit how much "G" force it can handle before the pin boss portion decides to let go. Cast pistons are good to a bout 3500'/minute mean velocity before they give it up. A light design helps. The other factors that will destroy a piston have more to do with excess dynamic compression causing detonation and poor tuning/excess tune.
I may have to just commission a set of light weight forgings from Bruce Walker(BWE Piston Rings).
Great guy to work with but spendy,$$$$$. The bores are already at .060 and after sonic check we determined to clean/square it at .070-075. Egge has Fuelie replicas at .080 on the shelf and as the originals they are a cast, solution heat treated to T-6 condition direct replacement. If I have to get a set made I'll keep them at .075 over and use a thinner ring package from a Chrysler 318 .040 over. Not really new to hot rodding, just haven't had time. Hod rodding to me has always been about using what I already have on hand and optimizing those parts to work together. You may leave horsepower in the parts catalogs but have more $'s left to keep the shop fridge stocked with beer.

 

You are probably right,,,,,but I have never seen a pin boss fail in these cast pistons .
Usually a skirt will crack and fail or the crown will separate.
A good factory cast piston is hard to beat,,,,in a street application .
I’m certain some guys may have had a pin boss failure,,,,,but I believe that is the exception and not the rule .

A custom set of pistons are the best,,, , top quality and excellent machining,,,,,,they can’t be beat .
But then,,,,,,your rods will be the next link,,,,,you had better upgrade them as well .
I hope this is an excellent engine for you .
BTW,,,,you never did say if it is a street engine or a racing package .

Tommy

 

Not going racing! I'm setting a 6500 redline with a 7k never exceed. Old people Sunday drive in the mountains or a ride to the beach for lunch.

 

Look into hypereutectic pistons then. I ran a set in my OT race car for 5 years. Shifted at 6500-7000 and thru the lights at 7000-7200. Car was not a street car.

 

If you bore to 4” I believe there are “off the shelf”
pistons/ring combinations. I’d check CP and SCAT. I would consider it cheap insurance. If your doing your own assembly a great engine can be built for a lot less than most folks think. We run a 1/2 mile dirt circle track 422” using a Dart block and heads and with only parts and some machine work run with the best of them.

 

Hypereutectic not available over .060. I need .070 to clean the block. .080 will work but .125 too thin for my '65 block.

 

Too thin on my '65 block.

 

I have a good crank and Scat small journal rods with ARP 2000 bolts. Just trying to get a good feel if the "fuelie" replacement pistons Egge has ON THE SHELF in .080 would be a good choice or do I need custom forged. 6500 redline with rev limit at 6800-7000.

 

Even for passenger car use I think the rods and crank must be magnafluxed. Wet fluorescent method is best.
The notches broached for the bolt heads are prime suspect areas for cracks to start.
A few cans of dye penetrant developer and penetrant (less than $30) is all it take to do a decent inspection, although only maybe 25% as good as Wet fluorescent mag particle done thoughtfully.
Small "indications" can be gently ground out.

The rod big ends must be round and the right size, and the rods need to be checked for straightness, and for proper wrist pin interference fit.
Unfortunately installing new bolts just about guarantees the Big ends will need to be reconditioned

As mentioned by others the price for quality rod reconditioning quickly gets up in the price range of decent aftermarket rods, although much increased rod weight is grounds for engine balancing. (more $)

I believe the OEM FI pistons were cast and had slotted (weak) oil return grooves.
I think they have no lock ring grooves, so the rods remain press fitted.
The ring grooves and pin bores must not be worn excessively.
No wire brushing or scraping the ring grooves to remove carbon.
After the pistons are carefully inspected, and dye pen inspected I''d probably drill a hole at the end of each oil return groove to create a lower stress detail than a milled slot, similar to what Chapparal did for their early race engines that used the factory forged pistons.
Also deburr that area of the oil ring groove too.

http://chevy.oldcarmanualproject.com/stuff/57csccg/index.html

fuel requirements
http://chevy.oldcarmanualproject.com/stuff/57csccg/57csccg21.html

Starting point ignition curve with real fuel and true 10.5-1 compression ratio.
Note it is quite bit different than the "all in by 3xxx rpm" recommended in later years.
http://chevy.oldcarmanualproject.com/stuff/57csccg/57csccg22.html

 

As long as the pistons that Egge has in stock are close in weight and quality to the original fuelie OEM pistons I would think you'd be more that OK using them based on how you described your intended driving. Save the money on the custom pistions and put a LOT of beer in the fridge.

 

GL flyer, you probably already know that there is a very limited selection of off-the-shelf 283 pistons. Why? Limited demand. The only way I would consider boring a block .150 to accommodate 4" pistons would be to have it sonic tested, then ask a machinist/builder if he will provide a warranty; not likely. Considering your intentions, I wouldn't try to save a few dollars; have custom forged pistons made that will accommodate metric rings. I prefer flat-tops and small combustion chambers to boost compression, not popups/domed pistons. If running pump gas, you'll want to keep you dynamic compression ratio close to 8:1, keeping in mind that a big cam/w lots of duration will lower the dynamic compression ratio.

The Fox-body Mustang 5.0 came with forged TRW pistons. Those pistons could take a beating, but it's not likely you will find any TRW forged pistons for a 283. I don't think you'll find any hypereutectic pistons either. You can also consider using a roller cam/w 60-degree V6 2.8-3.1 roller lifters, or you will need the link-bar, retro-fit lifters.

Some 283 cranks were forged, and the nose can be drilled and tapped to accommodate a harmonic balancer bolt.

 

Have you checked those heads and made sure that the combustion chamber fits inside the 283 bore diameter????......

 

With that info AND if your willing to pay for custom pistons, CP, Ross, etc. bore to the rings you can buy. It’s very important to have that in your back pocket before proceeding. They could even be a metric size. It’s no big deal for piston companies to make them as they usually make metric pistons also. They just list them in a different catalog.. I did this once when building a GMC 6 starting with a 270”which had a 3-25/32” bore stock. Good luck and balance when your done…

 

I put together a 315 HP 283 (Rochester FI) many years ago........used all genuine GM parts sourced through the local Chevy dealer. Never had a bit of issues with it frequently running up to 6900 RPM. You will need to pay attention to ALL of the clearances/tolerances to get you there.

 

One of the best answers so far, based on experience with a 283. I simply wanted to hear the voice of experience with the fuelie pistons and that's what I needed. Not my first engine build. Right now I'm setting the 6-71 blower on a destroked Chevy 400/327 crank motor. 6.25" H-beam rods, custom pistons and worked '492 heads. I also have 3 airplane engines in overhaul setting on stands in my shop right now. I've been building engines for fun and profit for the better part of half a century and even with that I've not ever used factory type fuelie pistons in a 283. I usually order customs when I do have something like this but if someone has a piston on the shelf, like Egge does I'll use them. If not, Bruce Walker at BWE Piston Rings is my go to guy. I have pistons he made in 2 of my airplane engines and I have complete faith in those engines. Even I don't use his pistons I'll get the rings from him.

 

Yes. Looks good with .060 overbore. Will be even better with .075-.080 over bore.

 

New pistons from Egge or customs, new rods Scat rods with ARP bolts.

 

I'll need help drinking the beer.

 

My 57 orig Fuely had factory type pistons with an 097 cam and the rochester unit. 283/283 .080 over-got the pistons out of South Carolina-maybe Wolverine?? Wound to 6500 easily and never had an issue-ran it for years-on the street and at the drags as well.. My 62 Corvette 340 hp had factory type pistons as well and 097 cam. Again 6500 many times no problem. The factory tach had a redline of 6500 as well so Chevy must have thought they would survive.

 

PERFECT! I'm all about using what works to do the job. the money saved goes to beer! Life's too short as it is.