Hot rodders....chevy ?
i got an old 327 i think, havent took apart yet. did look up head casting numbers on internet say they are these................................
3890462....66-67...302/327/350..Camel hump,no accessory holes,64cc chamber.
ok my question is with 64 cc chambers and engine with flat top pistons what compression ratio will this be?
and also what are the chances these heads have the 2.02 valves?
3890462....66-67...302/327/350..Camel hump,no accessory holes,64cc chamber.
ok my question is with 64 cc chambers and engine with flat top pistons what compression ratio will this be?
and also what are the chances these heads have the 2.02 valves?
0
-
I can't remember which one came out first and it hurts to try.Seems to me the 1.94's were first and I think first year for humps was 67-68 on the 302 Z-28.I don't remember if they ever put them on a 327 but for sure on a 350 in the L-46 application.350/350 HP.CR in the 10-10.5 range unless they've been decked.Sorry,I do remember the term Volumetric Displacement but can't remember how to use it in a sentence other than here.[:o)] Good luck with that[8D] 0 -
Try this link. It has several different things on SBC casting numbers. Hope this helps. http://www.thedirtforum.com/toolbox.htm 0 -
http://www.camaros.net/forums/showthread.php?t=24544
Read on down the thread. I am thinking 1.94's ( which actually are so dang close to being as good as the 2.02's ) with flat top pistons I would say 10.5-11 . Dome pistons would give you 11.5-12 CR. I've got a Chevy hot tune book around here somewhere for Mark BB's and smallblock motors how to tweak every ounce of horsepower out of them for racing.0 -
If it has been rebuild, there is a good chance they were decked/milled, so I'd say compression is closer to 11:1.
Ben0 -
To find out CR, use this link.http://www.thedirtforum.com/Cidcalc.htm Your combo comes out to be about 10:4 ratio. If you want to check your actual combustion chamber size(to see if the heads have been milled), simply turn your head upside down, with the valves in and facing up, and fill the cumbustion chamber up with a known amount of fluid measuring it in cubic centimeters. Most kitchen measuring cups are also marked off in metric. Hope this helps. 0 -
Your compression ratio is 10.25:1 with small eyebrow flat top pistons. 9.75 to 9.85:1 with aftermarket replacement pistons with large eyebrow pistons.
Most shops do not surface the heads unless they need it. Even if the heads have been surfaced, your compression ratio does not rise accordingly, because, the new hand gaskets are significantly thicker than the stock stamped steel.
About a 10% chance they are 2.02/1.5 or 2.02/1.6 valves in the heads. Of note, 2.02 intake valves do NOTHING for performance unless they are on top of a larger displacement engine at higher than 6500 rpms. If anything, you lose a bit of intake velocity which drops the torque curve slightly, but more than anything, decreases the ability of the air & fuel to atomize properly.
First year for camel hump heads is 1963 - 300 hp 327. Some 1962 small blocks had them as well - fuelie vettes.
1963-1967 are 64 cc combustion chambers. Some 67, most 1968, and all 1969 camel hump heads were 68 cc heads. The later heads were actually better because the chamber was reformed slightly and help to unshroud the spark plug - helps flame propagation in the cylinder (flame travel).
The intake port on these heads were copied in several other casting numbers of Chevrolet production heads - 441 & 442 castings with 72 cc combustion chambers.0 -
thanks....ok now whats double hump mean on these heads.....keep it clean[:D]
oh yea how do i figure out the manu date0 -
Doc,
Here's the best place to look for all types of casting numbers:
http://www.mortec.com/castnum.htm0 -
Your compression ratio varies with wether ypur pistons are the flat tops with four valve reliefs in them or they have two with two it would be 10.25-1. with 4 each of the valve reliiefs adds 1cc to yuor combustion chamber size making it 68cc 9.75-9.85-1 0 -
cowdoc,
My "462" heads have 1.94 and 1.50 valves.
The double hump, or camel hump, is a casting mark on the end of the head that indicates "so-called" fuel injection heads though very few were used on FI motors. I believe yours are standard
327ci - 300 hp heads.
Also, if it is up to a '67 the motor should have a small journal forged steel crank. It probably has flat top 10:1 pistons.0 -
quote:Originally posted by cowdoc
thanks....ok now whats double hump mean on these heads.....keep it clean[:D]
One more hump added to the single hump?
I have never heard of a clear definition. Of the later style double hump heads, there is a version that does not have double humps, but a right triangle.0 -
Are there any valve relief notches in the pistons? If so what are the ccs? What is your deck height? How thick is your head gasket and what is it's bore? With answers to those questions, you will be able to figure your compression ratio.[:D] 0 -
With a 64cc compression chamber and a dual valve releif flat top,..you'll be lucky to get 10.5:1 compression. I ran single valve relief flat tops (TRW) with 58cc compression chambered aluminum vette heads on my 350 4 bolt main motor,..and was getting 11:1 with .030" over cylinders. I would place a bet at closer to 10:1 if she hasn't been bored or stroked. Now if you have humped pistons,..then you are 11:1 easily and prolly a bit more.
now for the double hump.......look at the heads from the front of the engine, you will see casting marks (raised areas like rectangles or squares etc) in the front of them as you are looking at the front of the engine. If there are "double humps" instead of a single casting "hump" you have double hump heads,..which usually means the 64cc sompression chamber, but depending on what they came off of,..it could be either the 1.94 valves or the 2.02 valves.0 -
took the heads off today, they are the 1.94 valves...gonna take them to machine shop soon and get them gone through.
the heads on the 327 in my car are newer ones, havent took off a valvecover to get casting number to know for sure, but would guess they are the 76cc chambers...
the 327 i have that i tore down today, found to have an external crack about 4 " long at the very bottom of water jacket level[:(] had hoped to have a spare block to build up myself....oh well....been asking around about any 454's and the are none to be had around here.....guess have to get a 572.[}:)] hehe....i wish
the 327 in my camaro is built up but i did'nt build it so not 100 sure...was tld its bored .030 over has pretty good cam in it dont know what for sure i'll have degree it out, aluminum rods, edelbrock performer intake and edelbrock carb.....think the guy told me it had rhoads (sp) lifters....dont know if thats good or bad though. do have vacuum issues ... pry be alot worse without them maybe.0 -
DON'T bother spending the machining on the camel hump heads. By the time that you put in guides, valves, hardened exhaust seats, cleaning, magnafluxing, surface the intake and the deck, you can buy a new set of iron aftermarket heads WITH screw in valve studs and guideplates. TRUST ME....been down the road before...and I was the machinist - no cost, other than parts. Go with 1.94, 1.96, 1.98 necked/swirl polished stainless intake valves and 1.6 necked, swirl polished exhaust valves. Bronze guides are ok. Steel guides are the best.
Of note, if you really want to build an engine, go with a 400 block and a 350 crank (scat makes a drop in crank) and end up at 377 cubes. Go with a 2 bolt block and put a 2 bolt stud kit. This is stronger than a factory 4 bolt. The 2 bolt blocks have more meat in the webbing. Only thing stronger than a studded 2 bolt block is a splayed 4 bolt block with center studs.
377 combo allows quicker rev, good torque, better standard length rods, NO problems with clearancing the block, or pistons/valves, etc, etc.0 -
Almost forgot...put a LARGE cam in the 377 - something in the 500-510 lift and 288/294 duration...and make it a solid lifter. 0 -
I ran a comp 490 lift 282 duration in my 350 and it worked GREAT,..I shifted at 7000rpm with 4.10:1 gears and was solid gettin down the track ay 12.00 flat through the pipes and on street tires[}:)] 0 -
this car has 3.30 gears i think what i was told. need to to put 4.10s in it thats pry the first thing i should do i guess..also the best thing i should do is build a bigger engine for it....guess i bought the car for the body the 327 was already in it and i didnt build it. guess for me building an engine for it myself is what i really want to do.[;)]
did check with a machine shop today sounds like i can get them done for aprox 250 dollars.....guess i'll have to figure out which direction i wanna go with this...get the max out of the 327 or go bigger cubes.0 -
quote:Originally posted by JustC
I ran a comp 490 lift 282 duration in my 350 and it worked GREAT,..I shifted at 7000rpm with 4.10:1 gears and was solid gettin down the track ay 12.00 flat through the pipes and on street tires[}:)]
Not big enough for a 377.
I ran a 440 lift, 308 duration cam in my 350. Also ran a 488/288 duration in a 327 - shifted at 6800.0 -
quote:Originally posted by cowdoc
this car has 3.30 gears i think what i was told. need to to put 4.10s in it thats pry the first thing i should do i guess..also the best thing i should do is build a bigger engine for it....guess i bought the car for the body the 327 was already in it and i didnt build it. guess for me building an engine for it myself is what i really want to do.[;)]
did check with a machine shop today sounds like i can get them done for aprox 250 dollars.....guess i'll have to figure out which direction i wanna go with this...get the max out of the 327 or go bigger cubes.
Before you buy gears, figure out how tall of tire you want to run AND what transmission (need 1st gear ratio)...THEN buy the gears. You might only need 3.73. 3.73/3.91 seems to be about the perfect gear, but that is with a deep first gear ratio. 4.30/4.56 with a close ratio 4 speed or normal TH350. 4.88 with a powerglide or turbo 400. I HIGHLY recommend the powerglide. Go with an aftermarket case, internals, reverse manual valve body, 3500/4000 stall converter, deeper sump pan, & medium sized oil cooler, and be done with it.
$250 - what does that included?
Clean & magnaflux (should be glass peened and hot tanked after the peen - make sure that you can see ALL of the cracks) - $50
Valve job - $125-160
Guides - $80-120
Hardened exhaust seats - $80-125
Valves - spend what you want $160
Surface intake and chamber side - $100
To rebop your heads you are looking at $595 to $715
Get a WRITTEN estimate - I don't care how well you know them.
Sell your camel humps on Ebay and put the money towards some S/R Torquers or the like....TRUST ME.
First - what do you want to do with it? Trailer queen to the strip or are will it see street/strip duty?
If you go with the 377 I mentioned, just buy a good set of aftermarket rods (can go to 6.0 length), a LIGHTER set of pistons, and add a 200 - 300 shot of NOS for strip use.
As I outlined above....with a large solid lifter cam, good set of aftermarket steel heads, 9.75:1 compression, Holley Strip Dominator or Edelbrock intake, the basic engine is good for an honest 375-400hp at the flywheel. Add the NOS...you are in the 650-700 HP range....and still be able to drive it.0 -
DC, i want it streetable barely though and strip and damn sure dont want to be slowest car there
how much would i gain in power with 64 cc chambers vs i am guessing but pretty sure the heads on it are 76 cc the guy told me they are heads with casting num 333882.
the 327 is now .030 over with two valve reliefs trw flattops with the 76 cc chamber heads0 -
882 castings are 76 or 78 cc (when measured, they are actually 78 to 82/3 cc though). Most were of the "lightweight" casting design and are an emission style head. They don't breathe over 6 grand...pretty much done at 5500.
You will gain, without any other changes, 1 full point in compression and 50-60 hp.
Right now, you have, approximately, a 250 to 285 hp engine (at the flywheel, depending how/what the cam in it is). Would end up with a 300 to 350 at the flywheel, again depending how/what the cam in it is). Basically, right now, you have a 9.0:1 compression 327 with a cam. 250 hp would be a factory 327, minus the cam.
When building a small block, it is better to go with 76-80 cc aftermarket heads and fill them with 11:1 domed pistons - which settles the compression ration at the 9.8 to 10.1:1 compression (350 engines) or a small dome for the 377 build. Why? IF the domes are polished and the chambers are lightly to moderately polished ....between the domes and the polished surfaces, this helps flame propagation and gets rid of most of the hot spots caused by the cast surface of the combustion chamber. But, you MUST check intake AND exhaust valve clearance.
Cheap small block:
400 block - $100 (2 bolt preferred)
ARP 2 bolt stud kit - $60
Factory GM windage tray & pan - $100
Scat crank - $275
Aftermarket heads - $550
Aftermarket rods - 6.0 H beams - $200
Good pistons (flat tops) - $250
Rings - $50
Bearings/Gaskets - $145
Cam/Lifters/Valve Springs - $250
Titanium retainers - $50
Aluminum rollers - $150
Locking rocker hold downs- $40
Double roller timing chain/gears - $45
ZERO balanced bottom end - $150
Machine work - bore, clean, etc - $200
$2615 for a streetable 425 to 440 hp engine. Of course you are going to need an intake, carb, distributor, plugs, wires, fuel pump, headers, transmission, converter or clutch, gears, posi, & tires to put this to the ground.
You can build a 350 cheaper, but you do not get the torque or horsepower, due to the cubic inch difference.
Everybody probably think I am stuck on this combo...but look at the greatest engines in history - from single cylinder to multiple. The engines that put out the horsepower with moderate torque are ALWAYS big bore and mid length stroke. The bore on these engines is always larger than the stroke is...not close, but by a definitive margin.0 -
But for the same money or maybe a little more you could build a closer to stock big block with a lower compression ratio meaning less chance of detonation with today's low quality gas and later if you want more power it will be a lot easier to get with less money in the long run.
The big block may not make as much H.P. but will make a ton of torque down low witch in most street applications is what is most important a little effort with a die grinder on the heads, a decent intake, a good carb, and a mild cam will make one hell of a fun ride[;)]
P.S. when you choose a cam remember bigger is not always better0 -
Cowdoc,
If you decide to get a 454 BB; the 2 bolt main blocks can be converted to 4 bolt easily. Your machine shop can fit and install the 4 bolt main caps, line bore it and you're set.
I found a stock bore 454 2 bolt bare block at a swap meet for $100.00, rectangle port heads for $50.00 each -- all were rebuildable.
I had the 4 bolt main caps installed, used a forged crankshaft, LS6 pistons, stronger rods plus had it balanced. With the valve job, new valves/springs/cam, cylinder hone and having it put together I spent about $1400.00 plus parts.
In my opinion, big block is the only way to go -- due to the horsepower -- it doesn't take much to get over 400 HP and with a little work 500 hp is attainable.
It all depends on how much you want to spend.0 -
1st take them Rhoads lifters and make targets out of them, abosulte junk marketed at the guys who cam an engine to the point it idles like a Keith Black Hemi, sales pitch is all they are. They bleed off and collapse at low RPMs making the engine sound like it has a solid cam out of adjust, JUNK!
Decking the heads, you will need to have the intake done as well, decking the heads fubars the mating of the intake and should only done when absolutly necassary and done by an experianced machinist, Bubba Bobs Fix 'Em shop will mess them up every time. Brodix builds a mean head, check them out, most of the time Brodix needs no port work and almost off except the most expensive race heads needs porting. You can cam that engine to hell and back and dump ferocious quantities of fuel into it but with heads that have never been on a flow bench you are wasting money.
Cams, Summit Racing and other speed shops will dazzle you with all sorts of fancy sounding numbers that are always not what the cam actually is, look at advertised duration and actull duration, that mean sounding .305 is most likely nothing more than a .282. The centerline on over the counter cams is cut for street use resulting in lousy throttle response and performance. Call Comp Cams with the numbers you are looking for and what you have already, actual displacement, actual compression ratio, induction, how much fuel are you going to feed it, tire size, gearing, auto or stick tranny, tranny gearing and max RPM you want to be at when crossing the 1320 line. Comp Cams will grind you a cam suited for your application and it will cost the same as an off the shelf cam and work 10Xs better.
Compression ratio, I gather from your posts that you want a barely streetable engine, you are gonna cam it to dork correct? Well now the idea of a lower compression engine just went bye bye, you will need a high compression engine because once you install that Mt Everest Bump Stick in it you are going to bleed off compression, you will lose it in a hurry so a 9.5-1 engine is gonna suck big weenies with that big cam.
My favorite engine is the 383 Stoker, crank kits can be had at almost any speed shop, ready to install. All you need to do is do some die grinder work on the block, this is so simple a 6 year old can do this. You want mean driveshaft snapping torque? Go with the 383. You want HP and quick RPS to go with that torque? Go with the 383, it is the best of both the big blck and small block worlds.
But then again, kids today are making Hondas sound loike Go Carts and making them eat the average Camaro for lunch. Have you thought about a 4 banger?0 -
No doubt PaRedneck! That 383stroker is one potent combo.A friend of mine just had his 350 stroked to 383 in his 69 Camaro and wow what a ripper it is.
My goat has a mildly built 406 that puts out around 400hp.Im going to race it this summer after I stroke it to 462.Build includes:
4.25 Eagle crank
6.8 H-beam
FM clevit rod bearing
FM/CL main bearing
Ferrea .990x2.5" 125 gram pin
274XE Comp hydr cam
Edel 87cc ported Alum. heads
Edel performer RPM intake(port matched)
2" Doug's headers / 3.5" collectors / 3" pipes
estimated 560 hp & 625 lbs of naturally aspirated,big block whoop arse on 92 oct[8D]0 -
quote:Originally posted by Pa Redneck
But then again, kids today are making Hondas sound loike Go Carts and making them eat the average Camaro for lunch. Have you thought about a 4 banger?
"Have you thought about a 4 banger".....i dont give a flying F$%k about little boy racers rice grinders...0 -
If you find a 327 SMALL journal block....you've got something that is pretty rare these days.
Put a 283 (short stroke V8) crank in it and you can make a Chevy 302 screamer.
One high rpm screaming SOB.0 -
quote:"Have you thought about a 4 banger".....i dont give a flying F$%k about little boy racers rice grinders...
I don't like them either and I have so much fun stomping them on the 4 lanes with a Powerstroke diesel[:D][:D][:D]0 -
IF you do decide to go different go with the 383 stroker. Many variations to play with including putting a supercharger on em. I personally do not like nitrous. Damage can occur quickly.. 0
Please sign in to leave a comment.
Comments
37 comments