Well ...to late for that! Lol I just figured was a regular freeze plug...does it have to do with setting cam position as well?..engine has been at machine shop for a few days
The cam lobes are slightly tapered so the lifters "spin" ,this causes the cam to thrust rearwards and not walk. The rear face of the timing gear controls the distance of the cam on Chevys. When an engine is converted to roller cam [with parallel lobes] a cam button and/or thrust plate is needed to prevent "cam walk" Also when you buy an aftermarket timing set [eg: Romac] they come with a bronze thrust bearing or Torrington thrust bearing . If the front face of the block is damaged, a Torrington is a bolt in repair. [on race engines we cut a small groove in the front cam bearing bore [to allow a Torrington to be lubed at high rpm] Get the machine shop to install the cam bearings and freeze plugs [and gallery plugs] They can do this cheaper than hiring a cam bearing install tool. Ask him about the rear cam bore plug. [there is a change over year in 283's] The best DIY method is to install the old camshaft and timing gear [which runs against the front of the block] then you know how deep the rear of the cam journal is.
The chamfer on the bottom allows for a longer stroke [327 crank and 307 pistons] The 3789817 casting can be BORED to 4" so it can take longer stroke AND larger bore' Chevy used the 3789817 casting for both 283 and 327 bores [3.875" and 4.000"] Most early 283 [and some 265] blocks without the chamfer at the bottom can go out to 4.000" BUT they cannot take a longer stroke because there is water jacket issues. [unless the crank counterweights are cut down] Some of the later 283's [67-68] can also be bored to 4.000" but not your mid-year block. Personally , I would use a 327 crank [while the engine is apart] and cheap assed 0.030 over 307 pistons and stroke it. [It helps the engine to be lazier and not work hard] and dirt cheap. They are both internally balanced 307's only got the bad name because they were the little brother to the 350 [from 1969] whereas when the 283 was released in 1957 it was King Shit until the 327 came out. [305's suffer the same fate]
That all depends on whether you want to keep the original car's DNA! power packs keep that vintage look to the engine [and power packs were used on 327's in Impalas] A 307 stoker is totally invisible, even an expert couldn't tell when the engine is installed And every thing appears to be period correct! But crack test your heads first, you may have no choice. If I was considering 305 heads, I'd hunt down some L98 C4 Corvette aluminium heads. But "Less is MORE" keep the power packs if possible. They have withstood 60 years of use [and suit the character of the car] Maybe give them a good valve job [1.84 intakes]
Ok guys...its been a while but machine shop has had it for months ( there behind)...they want to go to 040 on the. Bore to clean up a good ridge at the top. And turn crank another 010 so it would be 20/20..was hoping could be polished ..I mentioned possibly going to 1.94 intake valves( or 1.84..or 305 heads? He didnt seem to think putting 305 heads on it was much of an improvement...said ya 1.94 valves would be good..I'm wondering if he's just picking my pockets.). ...here is the quote I was givin..let me know your thoughts...still planing on 4 bbl carb and Intake ( edelbroke) headers...still undecided on the rest.. slight cam upgrade..have these heads redone with slightly bigger valves...? Push compression up a tad? Rebiult rods new flat top pistons..? What do u guys think..or just using a rebiuld kit from northern auto parts in it with a cam upgrade and the above mentioned stuff. Again, just wanna pep her up a little and do what makes sense. I don't wanna over complicate this biuld.
Oh and ignore the parts pricing...thats obviously if I had him supply pistons and rings ect...he said they would be cast flat tops..didnt get Into brand tho. Def don't wanna go on the cheap. I want the engine to last most of all. Also he mentioned going to a retro roller setup if I wanted ...says he does it to all the older small blocks he does now but obviously quite a bit more money. I know ill probably have more money wrapped up in this compared to just building a 350 or buying something to throw in it.
As a comment on "picking your pockets"...the pricing shown on his quote seems to be the going rate these days. Around here, those numbers would be celebrated as economical!
Is going 40 over safe on this block? He didnt seem worried about even going 60 but obviously didn't want to if he didn't have to
Stock 283ci bored .030 Edelbrock RPM Performer Intake and 600cfm carb Comp Cam (480/480 Lift) Comp Cam 1.6 Roller Tip Rockers Comp Cam Push Rods and Lifter Comp Cam Double Roller Timing Chain Stock Forge Steel Crank Gridle and splash shield Eagle "I" Beam Rods TRW 11 to 1 Pistons 305 HO Heads with 2.02/1.88 Valves Dual Springs Valve Springs Saw this another forum...seemed like a cool biuld?
Sounds like a good combination - though it isn't really a totally budget build at this point. If I was going to put all of that into a 283, I'd probably just build a 350. Buy Hey - it is your car/engine, not mine! LOL
Usually not a problem but always depends on the particular block. In the 60's, boring a 283 block 1/8" (.125) over was common for building a 301. Nowadays the issue is piston availability.
And 2.02 valves will hit the bore, you have to relieve the top edge of the bore for clearance..... The biggest valve you can use in a 283 with a safe overbore is 1.94 I have fitted a 2.02 valve [one] into a power pack head to test on the flow bench. This was a head that some "expert" hogged out the throat with a Dremel and it flowed less than stock.[no velocity] By installing the 2.02 valve created a "bell mouth" or restored some venturi to the throat. This restored the flow in the head, but the real gain was low lift flow [.150" to .250"] I was going to try a 2.02 valve on a stock power pack head but couldn't find a "Free" candidate [the heads we used were "cracked" donations] My thinking on heads changed a lot after this experiment. Most people get mesmerized by maximum flow numbers but this usually only happens at peak lift. The valve spends more time "off the seat" either opening or closing, than at maximum lift. Also the engine needs to support the flow numbers. It is a waste of time [$$$] using high performance heads if the engine is spending most of it's time at lower rpm. [trying to accelerate] Which brings me to one conclusion, the best all round Hot Rod head for a street vehicle is a stock "un dicked with" Vortec head. They are good for 380hp and using long duration high lift cams, bigger valves will not produce any better results. But they are very good flowing even at below peak numbers.
If I was going to go with a vortec head on a 283 I'd get a set of 305 vortecs. Most of the same benefits but smaller chamber so you doubt lose a lot of compression like usual when putting a head off a larger bore engine onto a smaller bore.
True! but I wasn't actually suggesting that @bryan boswell use Vortecs. I was just pointing out that we all get seduced by romantic components which can be detrimental to our end results. Race engines and pseudo race engines are absolute dogs on the street. This a 283 in a street driven vehicle ,a realistic goal would be an honest 240-250 horsepower [but even then it will only be making those numbers when you wind it out] 90% of the time the engine will only be making 106-133 hp [2000-2500 rpm at 280 ft/lbs] Why bother with all these bullshit hot rod parts when the engine [and car] doesn't support it. With a 283 engine there are more gains to be made with rear-end ratios and different transmission ratios
On my own 283 build (57 power pack) I'll be going visual super power pack dual quad clone. Main deviations from stock power pack will be a modern equivalent of a duntov cam and 1.86 valves in original power pack heads(simply for warm fuzzy feeling lol)
One can spend an awful lot of time and money on stock cast-iron heads - trying to get some HP out of them. I like the idea of the 305 Vortec HO heads - probably the best bang for the buck. From the Web: The Vortec 305 head comes with 1.84" x 1.50" valves and use center bolt valve covers1. Another common 305 head for performance use is the 1980-'86 "HO" heads, which have nominal 58cc combustion chamber volume and 1.84" x 1.50" valves1. The 14022601 1979-'86 heads also respond well to porting and 1.94" intake valves1. The 376450 heads should be avoided as they have 1.72" intake valves1. The best flowing stock GM casting for a 305 is the Vortec truck head from the '96-99 GM pickups which came with a 5.0 305. They come with 1.85" and 1.50" valves and the casting number ends with 0592.
If you reversed the mathematics. Using stock Vortec heads which are good for 380hp on a 283, it would reach it's hp at 7100 rpm This is calculated using "the rule of thumb" formula of approx 1 ft/lb torque per cubic inch. [280 ft/lbs] The engine would need to be built to support this RPM range. Valvetrain / Cam / Compression If the same heads were plonked onto a mild 383 stroker it should make the same power at 5250 rpm But with 380 ft/lbs, it would be a lot more driveable down low A 383 stroker with 380 ft/lbs torque x 3.55:1 rear end ratio will have exactly the same axle torque as a 283 with 280 ft/lbs torque x 4.81:1 rear end ratio. [and the wheel speed is the same when comparing 5250÷ 3.55 to 7100÷ 4.81] Personally for a 283 the best bang for the buck is gear ratios and transmission swaps [keep the power pack heads]
Still look like late model heads I don’t care what anyone runs could care less about hp if ya want the old look, ya need old parts
If I stick with the power packs should I maybe just go to a 1.84 intake would a 1.94 not be worth it?
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