|11-05-2009 11:48 AM|
I'm building one for my 1970 truck too. It's all about fun and gas mileage. They don't have to be mutually exclusive. 283's have always been smile makers. Even though I've built some blown 355's, and they are impressive, there is something about firing a 283 and hitting the street
From what I've found the cam timing for intake closing is a bit more critical for little motors and the shorter stroke (relatively) 283 in particular. Not getting wild with the cam will make a huge difference. Over cam a 283 and it falls flat on its face at street speed. Older small cams can pay dividends with 1.6 rockers on the exhaust side. But if you've done your port work on the exhaust short side, it'll run fine between 4 & 5 grand. That's about all you need in truck pulling a short steep hill or something.
|09-16-2009 08:06 PM|
|09-16-2009 07:41 PM|
|pt-19boy||Well that makes me feel a lot better, Thanks tech and sedan.|
|09-16-2009 06:39 PM|
Tech didn't mean cheaply made. There just cheap priced stock style Cast pistons. They'll work fine for a mild Street/Strip engine, no Nitrous or Forced Induction tho'. $120 compared to something like these Hypers. >> http://www.summitracing.com/parts/UEM-KB165-060/
Typing at the same time.
Nasty weather, raining so hard satellite signals gone.
|09-16-2009 06:35 PM|
Not that there is anything wrong with a cast piston being used in the right application. There are millions upon millions of motors out there serving their owners admirably every day with cast pistons in them. It's just that they won't tolerate abuse as well as a more expensive hypereutectic or forged piston. As long as they aren't over-heated or over-revved, are kept out of detonation and not called upon to tolerate excessive cylinder pressures, they will most likely outlast the other components in a daily driver motor.
I built this 283 as a daily driver, with low static compression ratio, a cam matched to the static compression ratio to prevent excessive cylinder pressure and cam timing meant to limit rpm's. You'll notice that the cam is all done by 5000 in this combination. Providing the motor with the proper air/fuel ratio and proper ignition timing would produce a motor that would give good service for quite a long time, even with cast pistons.
Hypereutectic pistons are still cast pistons, but they are produced with an excessive amount of silicon added to the aluminum alloy. This controls their expansion characteristics better than a conventional cast piston and allows heat-treat to stiffen the casting. Here is an example of a hyper piston that I might use if I were going to go with a better piston over a cast unit....notice the compression height....this piston is 0.025" taller than the cast piston I used in the DynoSim and would allow the use of a more conventional 0.040" thick composition-type head gasket with the same 0.060" squish we had with the shorter piston and shim gasket. Chevrolet makes a composition gasket under part number 10105117 that is 0.028" compressed and would yield a squish of 0.048" with this piston and a stock block deck height. (+/- 9.025")
Forged pistons have been and probably always will be used in applications calling for the toughest piston available. Their higher cost is palatable to those builders who require the best piston available in a high-performance or racing atmosphere. A set of forged Venolias could be had for around $450 according to pricing on www.flatlanderracing.com
|09-16-2009 05:48 PM|
Techinspector1, I don't even know where to start, that post has so much good information in it... i can't even start to say how much i appreciate it.
But i can say this, You are the man!.
And it's not that i don't have any money to put in the motor i just don't want to buy another motor and waste a good ol' 59 sbc 283.
But the pistons are definitely something i don't want to skimp on, unless those federal mogul pistons are any good? ( i don't know anything about pistons) but you did say that they were cheap, and that scares me.
|09-16-2009 03:19 PM|
|09-16-2009 03:13 PM|
Techinspector1, there's a little Flow Info here on the 416's and 601's.
I read a few places the 601's flow better than 416's.
Can't find other threads.
|09-16-2009 02:55 PM|
|Plaintoast||I agree with much of what you said, but what is listed as "noticeable idle" will be "very noticeable" in a smaller cube engine like this.|
|09-16-2009 02:39 PM|
F-BIRD'88 fiddles around more with these 305 heads than anyone I know, so he would be the go-to-guy on these. This thread is interesting enough to me though, that I have done a little research and come up with a budget build that might be just the ticket for a daily driver.
The bugaboo in running a valid DynoSim is having valid head flow figures and I really couldn't come up with any for the 14022601 heads that would seem to be the logical choice on a budget 283 build. I did find some on the 14014416 head, so I just used them. They seem real enough....
0.100" 51 44
0.200" 112 94
0.300" 154 123
0.400" 175 134
0.500" 184 136
0.600" 185 137
I don't know what the true cc's are of the 601 chambers, I saw 53 and 58, so I ran a Sim on both volumes.
The value of a DynoSim is not necessarily in the definitive numbers, but in being able to change parts until you get the best numbers from a particular combination. That's what I have done here.
This will be the cheapest 283 build I could put together to make decent street torque (horsepower sells motors, torque moves cars). One of the problems with a small displacement vintage motor like the 283 is finding affordable pistons that have a decent compression height. There just are no such animals out there. To get the right CH (1.800"), you have to spring for high buck hyper or forged units. I didn't do that here, so we will have to live with what we can get for cheap (cast,1.780") and use a 0.015" shim gasket to help make up for it. A tight squish shouldn't be a necessity here anyway, with the relatively low static c.r.
283 block, bored +0.060" for a displacement of 292CID, using these cheapo pistons....
The whole idea here is that you have this 283 and can't do any better right now (350/400) financially, so we're going to spend as little money as possible.
14022601 heads from a '79-'86 267/305. There are several reasons to use these heads....
1. small chambers to make a decent static c.r. on a 283.
2. drilled and tapped for bolt-on accessories, unlike early 283/327 heads.
3. takes conventional '55-'86 intake manifold, stock or aftermarket (no high-buck Vortec intake required).
4. decent stock flow for feeding a small displacement motor, with lots of potential for porting and making really good heads out of them.
5. they're affordable.
We'll change out the springs, using a set of Z-28 springs and retainers in a kit from www.sdparts.com
See the bottom of the page for retainers and locks. To keep things cheap, we'll re-use the stock stamped 1.5 rockers.
Intake manifold: I used a standard Performer intake on this build and made good power. A stock 305 intake might even do a little better job in the low rpm torque department, but the 2101 is cheap (especially used) and will take off a little front-end weight.
Camshaft: Even though I dislike using a flat tappet cam because of oil issues with currently available off-the-shelf oils, I'm going to use a flat tappet hydraulic cam on this build just to keep the cost down. We'll assume the builder knows how to take precautions in the assembly, break-in and daily operation of the motor to prevent poochin' the cam. I would use the stock valve springs to break in the cam and then change them out for the Z-28 springs after break-in. The Z-28's should present less than 300 lbs to the tappets with the cam we're going to use (297.6 lbs on the exhaust at full lift), so should work ok after break-in. DO NOT INSTALL THESE Z-28 SPRINGS TO BREAK IN THE CAM.
I guess "noticeable idle" means you can tell it ain't stock.
Carburetor: This motor will need no more than 600 CFM. It really won't need that much, but that's the cheapest carb.
The only item we will have to spend a little money on is the headers. The motor will want 1 5/8", long-tube, equal-length headers. I Sim'd it with shortys and stock logs and either of them just killed the motor. Use a good-quality header with a 3/8ths inch or thicker flange, such as Hedman. 2 1/4" pipes would be more than enough. I might use 2" with an "X" pipe right after the collectors.
OK, here it is with 58cc chambers, 9.0 SCR...
RPM HP TQ
2000 122 320
2500 154 324
3000 186 325
3500 228 342
4000 260 341
4500 284 331
5000 300 312
5500 293 280
Peak volumetric efficiency 86.9% @4500
Peak BMEP 176.7 @3500
Same everything, but with 53cc chambers, 9.45 SCR
RPM HP TQ
2000 124 325
2500 157 329
3000 189 331
3500 232 350
4000 265 347
4500 289 337
5000 305 318
5500 301 287
Peak volumetric efficiency 87.5% @4500
Peak BMEP 179.6 @3500
|09-16-2009 02:30 PM|
|SSedan64||Sounds like it was a fun ride Vince. A Cousin of mine had a 64 Chevy Short Bed P'up, Built 283, 4-speed. It would wind up. We didn't have the belt problem, did have a exploding clutch problem tho' shifting into 3rd and a long walk home. What a racket, could see chunks bouncing out the back on pavement.|
|09-16-2009 02:03 PM|
The PowerPack heads were just a suggestion to keep the engine period correct if that was desired.
Having said that: I had a 56 Chevy 210 sedan back in 1968 with a 283 .060 over with SpeedPro forged flat tops. The heads were stock 186 castings with screw in studs and guide plates, and a Crower rev kit. I don't remember the cam specs, but it was also Crower. I also had a dual plane Edelbrok aluminum intake similar to the Chevy Corvette. Mallory dual point with Mallory coil. Carter AFB carb, small tube steel headers. Car was equipped with a Muncie 4 speed with 3:70 open differential. I have no idea what the actual hp was, but the car was an absolute blast to drive. It would rev to 7K at the drop of a hat and did so on a regular basis. Each time I would have to bend the alternator fins back or reinstall the alternator belt. The car was still running strong when I sold it to go into the USAF in October of 69. One of dumbest things I have ever done...selling the car that is.
|09-16-2009 01:11 PM|
Since you've bought the parts you may as well build a gas sipper with descent power. With the price of gas you may like the 283.
Look for the 601 truck or 416 SS Monte,Camaro etc.. 305ci heads. They are about 58cc + or - a cc and are the best small chamber factory heads.
Have 1.84" Intake & 1.50" Exhaust valves. Are much better than PowerPack's.
cc Info here is incorrect >> http://www.chevytech.com/3c14022601.html >> http://www.chevytech.com/3c14014416.html
Here's a few 305 builds for power comparison of small bore, it does have the 3.48" 350 stroke tho'. >> http://www.hioutput.com/tech/290hp/290hp.html >> http://www.hioutput.com/tech/343hp/343hp.html >> http://www.hioutput.com/tech/400hp/400hp.html
Some factory 57-67 283 HP/TQ numbers here.>> http://www.chevytech.com/1c1.html
Techinspector1 > What would the 58cc Swirl Port heads work like on the small 283?? Crap or descent? >> http://www.chevytech.com/3c14102193.html
|09-16-2009 11:36 AM|
|09-16-2009 11:16 AM|
Ther best advice so far!
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