Also if you raise the compression you will have to have high octane fuel not to ping.
Big Block Chevy
- Thread starter Taildragger
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Not too mention the weight savings the aluminum heads have over those cast iron monsters. If it was mine id replace the top in with quality aluminum heads and intake. Keep the originals so you can always put it back stock.
Like all these guys have said, just set your engine aside. There are thousands of 454 engines in the wrecking yards and nearly that many on Craigslist ...
Don't cut your Iron heads. You'll have to take something like 0.050" to get anywhere near your desired and by then the corner pads will be gone. So they'll be a dead give away as cut heads and will be practically useless and worth a few $100 at most.
Put aftermarket aluminum heads on it. It'll take roughly a 100 lbs off the front end so the car will drive better and it'll run a whole lot better. By the time you "massaged" the iron heads enough to get it to really breath, you'll have over $1,900 in them IF you can find a good porter who really knows his stuff AND is willing to grind on iron heads any more ...
AFR stock castings breath pretty well. Wieand Stealth intake will drop right on and not raise your carb by more then about 1/4". It'll feed the heads. Your Q-Jet will work fine
Junkyard bottom end can be built any way you like. Just freshen up, or go whole hog with bore and stroke to near 500 ci.
No Muther Thumps cams please ... For a flat tappet in a BBC, you should contact Cam King and get one to match your combo (once that's planned out). You could run a catalog cam from Crane, etc. I'd stay away from Comp, but that's just me ...
Lifters are the key to long lived BBC's with higher than stock valve spring pressures. I'd go Crower Cam Saver or Howard's Direct Lube. Wouldn't use anything else. Delphi if stock cam and springs, but still prefer Crower. Cloyes timing set, etc.
As far as CR goes, that depends on pistons. Small dome hypers are easy to live with. Cut the block decks so you end up with a 0.050" quench including gasket and that will mean no ping/knock no matter how bad the gas gets in the future.
Built HEI with the right curve to match to the cam and heads and you're good to go. Small groove in the lower casting boss to put extra oil onto the cam gears. Drill the front lifter gallery plugs 0.030" to over oil the timing set continuously. HV pump with lowest pressure spring to keep the load down.
A bit wide on the rod clearances to sling plenty of oil on the cam and cylinder walls. Oil filter boss by-pass blocked so that all the oil goes through the filter all the time. Oversized filter so there is plenty of media to flow the volume. WIX filter. You don't care about media efficiency, you want tough and you want to catch damaging bits. You'll change oil often enough to not worry about microscopic stuff. You'll have a small pan, so volume is needed somewhere in the system... Windage tray, etc. Me, I'd run an hydraulic filter with no internal by-pass. But one with a high number like 20 psi would work...
500 HP is easy enough on pump gas w/o straining anything. 600 HP is in reach on pump gas, but it'll idle a tad rough. 650~700 is possible, but it won't idle easily and it'll be scary quick once it comes off idle
Things down the line will break.
You didn't say if this is an auto car or a 4 speed ...
Oh, sorry - about the oil, Valvoline VR-1 to break in. Change it and filter at 100 miles. Cut open filter and look. Do it again in 1,000 miles. Use magnetic drain plug. Glue flat magnet to bottom of pan near drain plug. If any big bits are on the drain plug magnet, stop and tear it down and find out why... If just a bit fuzzy with iron from machining, OK. 2,500 RPM (up/down) for 15 minutes with a fully primed oiling system on first start. Make sure the carb is full so it lights quick. No prolonged starter cranking ...
Crane cam lube (goo) on all the lobes during assembly. No thin Comp red lube. It'll have all run off by the time the motor is assembled and in the car. Cam lube is critical on first cold start ...
Don't cut your Iron heads. You'll have to take something like 0.050" to get anywhere near your desired and by then the corner pads will be gone. So they'll be a dead give away as cut heads and will be practically useless and worth a few $100 at most.
Put aftermarket aluminum heads on it. It'll take roughly a 100 lbs off the front end so the car will drive better and it'll run a whole lot better. By the time you "massaged" the iron heads enough to get it to really breath, you'll have over $1,900 in them IF you can find a good porter who really knows his stuff AND is willing to grind on iron heads any more ...
AFR stock castings breath pretty well. Wieand Stealth intake will drop right on and not raise your carb by more then about 1/4". It'll feed the heads. Your Q-Jet will work fine
Junkyard bottom end can be built any way you like. Just freshen up, or go whole hog with bore and stroke to near 500 ci.
No Muther Thumps cams please ... For a flat tappet in a BBC, you should contact Cam King and get one to match your combo (once that's planned out). You could run a catalog cam from Crane, etc. I'd stay away from Comp, but that's just me ...
Lifters are the key to long lived BBC's with higher than stock valve spring pressures. I'd go Crower Cam Saver or Howard's Direct Lube. Wouldn't use anything else. Delphi if stock cam and springs, but still prefer Crower. Cloyes timing set, etc.
As far as CR goes, that depends on pistons. Small dome hypers are easy to live with. Cut the block decks so you end up with a 0.050" quench including gasket and that will mean no ping/knock no matter how bad the gas gets in the future.
Built HEI with the right curve to match to the cam and heads and you're good to go. Small groove in the lower casting boss to put extra oil onto the cam gears. Drill the front lifter gallery plugs 0.030" to over oil the timing set continuously. HV pump with lowest pressure spring to keep the load down.
A bit wide on the rod clearances to sling plenty of oil on the cam and cylinder walls. Oil filter boss by-pass blocked so that all the oil goes through the filter all the time. Oversized filter so there is plenty of media to flow the volume. WIX filter. You don't care about media efficiency, you want tough and you want to catch damaging bits. You'll change oil often enough to not worry about microscopic stuff. You'll have a small pan, so volume is needed somewhere in the system... Windage tray, etc. Me, I'd run an hydraulic filter with no internal by-pass. But one with a high number like 20 psi would work...
500 HP is easy enough on pump gas w/o straining anything. 600 HP is in reach on pump gas, but it'll idle a tad rough. 650~700 is possible, but it won't idle easily and it'll be scary quick once it comes off idle
You didn't say if this is an auto car or a 4 speed ...
Oh, sorry - about the oil, Valvoline VR-1 to break in. Change it and filter at 100 miles. Cut open filter and look. Do it again in 1,000 miles. Use magnetic drain plug. Glue flat magnet to bottom of pan near drain plug. If any big bits are on the drain plug magnet, stop and tear it down and find out why... If just a bit fuzzy with iron from machining, OK. 2,500 RPM (up/down) for 15 minutes with a fully primed oiling system on first start. Make sure the carb is full so it lights quick. No prolonged starter cranking ...
Crane cam lube (goo) on all the lobes during assembly. No thin Comp red lube. It'll have all run off by the time the motor is assembled and in the car. Cam lube is critical on first cold start ...
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There's really no reason NOT to use a break-in oil unless you're getting roller lifters. Why risk it?
That said, if you're worried about numbers, leave the engine alone and put something else in there. Even a (relatively) cheap reman should put out modern horsepower on unleaded gas and be reliable.
That, or LS/LQ swap it.
That said, if you're worried about numbers, leave the engine alone and put something else in there. Even a (relatively) cheap reman should put out modern horsepower on unleaded gas and be reliable.
That, or LS/LQ swap it.
I would use a cam break in lube of some sort if nothing was supplied.
Aluminum heads allows you to run one point higher compression without a need to increase the octane. Due to thermal energy loss or something.
Numbers matching cars are becoming more moot unless you have something special like a 63' stingray split window 327 or other high value collectables.
The generation that bought those classics new are dieing off. The generation who buys a classic 70's Corvette nowadays and has money mods the engine
or does an engine swap. Is a California 1980 Vette worth more if it has a numbers matching 305?
Aluminum heads allows you to run one point higher compression without a need to increase the octane. Due to thermal energy loss or something.
Numbers matching cars are becoming more moot unless you have something special like a 63' stingray split window 327 or other high value collectables.
The generation that bought those classics new are dieing off. The generation who buys a classic 70's Corvette nowadays and has money mods the engine
or does an engine swap. Is a California 1980 Vette worth more if it has a numbers matching 305?
In Kalifornia some number won't make it through smog ...
But pre-1975 is exempt
But pre-1975 is exempt
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Be careful not to put the lifters in upside down. I didn't notice until the pushrods fell over and jammed up everything. I pulled the intake and corrected the lifters and poured some STP in the bores to lube the cam. It was real hard to getit to turn over fast enough to start but it finally did! Runs lumpy like some cylinders aren't doing their job or something. I probably need hotter sparkplugs. I swapped one from the gokart and it helped. I envy your corvette! I have an Impala with no shocks. Looks like the mexican cars trying to jump as I drive, really cool.
Originally Posted By: Piston_slap
Be careful not to put the lifters in upside down. I didn't notice until the pushrods fell over and jammed up everything. I pulled the intake and corrected the lifters and poured some STP in the bores to lube the cam. It was real hard to getit to turn over fast enough to start but it finally did! Runs lumpy like some cylinders aren't doing their job or something. I probably need hotter sparkplugs. I swapped one from the gokart and it helped. I envy your corvette! I have an Impala with no shocks. Looks like the mexican cars trying to jump as I drive, really cool.
Nice try.
Be careful not to put the lifters in upside down. I didn't notice until the pushrods fell over and jammed up everything. I pulled the intake and corrected the lifters and poured some STP in the bores to lube the cam. It was real hard to getit to turn over fast enough to start but it finally did! Runs lumpy like some cylinders aren't doing their job or something. I probably need hotter sparkplugs. I swapped one from the gokart and it helped. I envy your corvette! I have an Impala with no shocks. Looks like the mexican cars trying to jump as I drive, really cool.
Nice try.
Originally Posted By: Piston_slap
Be careful not to put the lifters in upside down. I didn't notice until the pushrods fell over and jammed up everything. I pulled the intake and corrected the lifters and poured some STP in the bores to lube the cam. It was real hard to getit to turn over fast enough to start but it finally did! Runs lumpy like some cylinders aren't doing their job or something. I probably need hotter sparkplugs. I swapped one from the gokart and it helped. I envy your corvette! I have an Impala with no shocks. Looks like the mexican cars trying to jump as I drive, really cool.
You're like the green potato chip. One in every bag.
Be careful not to put the lifters in upside down. I didn't notice until the pushrods fell over and jammed up everything. I pulled the intake and corrected the lifters and poured some STP in the bores to lube the cam. It was real hard to getit to turn over fast enough to start but it finally did! Runs lumpy like some cylinders aren't doing their job or something. I probably need hotter sparkplugs. I swapped one from the gokart and it helped. I envy your corvette! I have an Impala with no shocks. Looks like the mexican cars trying to jump as I drive, really cool.
You're like the green potato chip. One in every bag.
Naw, it's just an Oregonian way of doing things
To the OP, if keeping a factory appearance is important to you there are heads available to do that and keep it looking stock. What engine is in your 73? If it's an LS5 it should have 820 heads which have a slightly smaller chamber than the 049/781 castings. If it has the 049/781 heads swapping to a pair of 820's would help the compression some while still looking stock. As for "numbers matching" unless someone pulls the valve cover you'll never know as all of the numbers are under the valve cover on a BBC. Personally I'd install a pair of Edelbrock heads, they're available with a 110cc chamber and would get you the compression increase you're looking for and be a real benefit to your new cam. If this engine has flat top Pistons you're never going to get anything meaningful for compression from production open chamber heads so if it does have flat tops perhaps a set of early closed chamber heads would be in order to get you the compression you desire.
For the cam I'd highly recommend calling Chris Straub at Straub Technologies. I've had fantastic luck with his cams in a street and race BBC.
For the cam I'd highly recommend calling Chris Straub at Straub Technologies. I've had fantastic luck with his cams in a street and race BBC.
some people have no sense of humor.
Valvoline conventional 10w40 w/Lucas' ZDDP break-in additive, then VR1 afterward if you think the cam's mean enough to warrant extra Zinc. 454's are tough and not necessarily picky about oil, but the old high-perf. engines can get pretty tough on oil.
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