Part 3 -GM Oval Port Head Core Selection - What To Look For In Depth Performance Engine Build 620+ Horse Power Street/Strip Pump Gas 454 Big Block Chevy
I used a set of these heads that were ported and had 2.190 1.880 ss valves in the mid 80s when there wasn't so many aftermarket heads available. They worked better than rect. Ports for the everyday driving , the low end torque was much better. Today aftermarket would be more economical
This guy did an excellent presentation. I've experienced a lot of different procedures on big-block Chevy Suburban cylinder heads and everything he says is valuable
I picked up a set of 1971 820's about a year ago for 100 bucks. Had them checked, everything renewed for another 150, I have no extreme build, but about 450 Hp with about 425 -450 ft pounds of trq.
These video series are amazing, really enjoy the detail precision, learning lots! Love my iron headed big block, great practical build!! Really appreciate it.
Thanks very much for the info on the stock iron cylinder heads! I struggled to find as much info as you gave, thank you very much. To heck with all of those Rich, aftermarket aluminum snobs!
Some of the other heads work just as well, I made 611 on 93 octane with a Gen IV 454, had pistons just to give me room for more cam, no added CI (~18cc dome) ported/built 088 heads, aggressive cam, Victor 454R, QuickFuel 850 carb. Was an absolute blast in the 1970 Monte SS I had it in. Definitely a car I wish I’d never sold off. 😔
Good job been building BBC since 396 and tons of power turning only 6000rpm last forever. Smiled I'm old guy and everytime I do a little I bleed too! Nice of you to save people from common mistakes! Thank you for sharing, from Georgia old hotrodder!👍🏻👍🏻👍🏻 A 68 Camaro RS untouch tired but all there left at my barn. One week after I buy a 53 impala...day late! Ha ha great job!
If you have the core shift where the gasket doesn't match up like the one bad head in this video, it will take you A-LOT more time to get the ports done the way mark teaches in this series! I already had too much invested to back out so I proceeded anyways. Plan on 15 hours per head not including the chamber work. I've ported a lot of sbc heads. The BBC take a lot more time! I still have one head to go. And yes, I was using carbides the whole way with extra pressure on those port openings. I'm going to get these flow bench tested just to see how close I got to Mark's heads. Duplicating the venturi is pretty challenging mostly because of how close you are to the seat. Take your time.
This is very good stuff, have a jet boat bud that can take junkyard stuff and single dominater and run 120 when 40 grand wont get most folks there. My question is will the vortec 454 heads flow enough to support 5 or 6 hundred hp. Or are the 70s still a better bet. Thanks.
I like watching you're tutorials on the bbc, I've done plenty of SBC for myself and assisted with some bbc builds and am building my first bbc for myself and so far I started with a nice set of 781s... my question is, I know you get the most power from a solid cam but I'm looking to run a hydraulic, what is a good lift, duration, lda, ls, etc to look for, this engine may or may not be sprayed and I'm looking for overall broad tq and hp, be a driver and get good numbers at the track, also what would a good cr be, 10:1, 11:1 and pump gas compliant?... thanks in advance for your time and help.
Dear friend... Because I'm old enough to have rowed thru the gear's of many a 396 Chevelles and a few Chevy Big block GTOs I can tell you with certainty we were ALWAYS on the look out for the Big rectangle port Big block head but with the advent of today's cheaper Great flowing quality aluminum head's so plentiful I can also tell you We don't have any Cast iron head's customer's unless they are the purest who have a NHRA class Stocker ..
Why the hell don't "know it alls" like you take the time to talk to the customers of this man & his shop. Because there's many of them, and they all swear by this guy and his abilities with these heads. I've already read statements from quite a few of them. And YOU ( just like all the other critic/"know it alls" ) make it painfully obvious that you don't possess the knowledge that this man has, to make these heads work great for A BUDGET BUILD that runs like a bat out of hell on pump gas and lives. And you just REALLY said a mouthful when you stated quote: "we don't have the customers for iron heads unless blah blah"..........Gee, that's awful damned funny, because THIS man & HIS shop obviously does. He lets his quality of work, the end product, and his satisfied customers do all that kind of talking.
ALWAYS A BIG DEBATE BACK IN THE DAY OF OVAL VS RECTANGULAR, I THINK ANY HP GAIN WAS FROM THE LARGER VALVES BACK THEN AS THE RECT. HAD BIGGER VALVES, LOTS OF RACERS USED OVAL AND GOT LOTS OF POWER FROM THEM
Not to change the subject but I have at pair of 6272292's that cc'd at 115. How does someone figure out, or select, the proper dome shape as not to interfere or hit the head? Does Mahle, TRW, etc. have a list of heads and pistons that work together? Sorry for the newbie type question.
Mark, got some 3917215 BBC oval port heads that I'm building for a 454, 500ish horse. Curious if you've ever flow tested those or if you think good or bad of them?
When I built my big block they said go open chamber. I did that and took them to a great machine shop who did a lot of circle track engines. The engine performed beautiful but by time I was done with the heads the cost made me think I should’ve went aftermarket but back in the day there wasn’t too much available and they were out of my price range so I thought. Well that engine is still in my Chevelle 30 years later.
It wont take much to make them flow better with the right port grinding. Easy 50 horse. Watching lots of videos and books, I got my small block 462 fuelie heads to go from 220cfm to 270 cfm. I have to run cast iron for class rules. Quite a bit more than stock vortec heads. The vortecs like to crack between the seats, and I didnt have a set anyway.
Get ahold of Butler Performance,or Kauffman racing,they are Pontiac experts bro.....I am a Pontiac nut also....Gotta love that LOW end Pontiac Torque!!!
Can I get your opinion on a closed chamber 206 head for use on a 19 70 402 ci . I like the 049 but would like to have a tame but decent street strip driver
I've needed to relieve the quench side of the chamber behind the exhaust valve and a small area by the intake valves to clear several of the FM (Speed Pro) forged and hypereutectic pistons when using 781's, I'm curious to see if Mahle's domes clear the chambers without those modifications. FWIW for your other viewers, the later 781's work out to about a 1.800 or so installed height, workable with a smaller diameter valve spring but generally a pain in the ass to deal with. Much better to deal with the early castings since the valve spring selection is much easier to deal with, regardless of the cam chosen.
@@canabox7112 In 40 years of building motors and cars/trucks EVERY machine shop seems to have that attitude. I think its something to do with the trade because I like doing things MY WAY also. hehe
Machinists have it worst, since they do precision work. But I get plumbers and electricians who begin every job with, "what gorilla did this work? jeeezzzz". I even had an oil change guy come out and show me a stripped plug and asked who did the last oil change. I said "check your records. You did it" that ended the attempt to sell me a new plug.
I have a set of big black Chevy oval port heads I believe they're overboard though casting number at the end is 820 was curious if these are worth using Just finding something else
I just picked up a clean set of 292’s for $200. They have good guides no rust pitting and passed the magnaflux inspection. They still have stock valves and don’t appear to have had any work done to them. Are these heads good candidates for a performance build?
i have a 80's 454 stroker crate motor all factory with 6000 miles on it 450 hp at 485 torque how much power can i get out of the stock heads i have put a 650 carb on it have a tunnel ram for one carb would like to put it on and a bigger cam looking at after market cast iron heads for it but they have a good price for them trying to stay cheap so for i got everything for free trying to see how nice an cheap i can build a 68 pu the pu has a nice clean body with faded factory paint needs paint and wood in the box all chrome is still on it
Mark if I took a 454 went 11 or 12-1 afr 265 head single plane and healthy Isky SFT would that be capable of getting my 67 CAmino in the 10s or at least bottom 11s reliably Guessing a 2 bolt cast crank is out....ballpark of what you would charge for this shipped to SoCal
So the that decked my heads and block was full of it when he said that was going to be good for my 454 . But fore some reason I bought two seats of headers and both have leaks up against the heads on number one exhaust port and number two exhaust port I don't know what to do with it if you have any ideas please let me know thanks
Phillip Filides you can use orange high temperature Permatex and wait until the gasket gets tacky put the two in bolts on each end of the header. to hold it in place put blue Loctite always on the header bolts. And tighten header bolts inside going to the outside just like a cylinder head pattern. Also keep tightening from the inside out until the bolts are tight not snug but tight. And if you have to cut a closed-end wrench into and use a socket and extension to sleeve the broken wrench to get more leverage on it you can or use a small thick wall pipe to put over the cut closed-end wrench for more leverage that's what I do or use another wrench with the clothes inside on the cut end wrench.. I don't use Permatex because I never have any leaks luckily since I started using Loctite. Headers have a bad name for the bolts coming loose and gaskets blowing out. since I've been doing this my way no more blowouts of header gaskets. Also don't worry I use blue Loctite on aluminum heads on the header bolts for iron or aluminum they have never gotten stuck. They always come out easy. And on projects I always use nylon lock nuts when I can if I can't use a nylon lock nut. I always use blue Loctite on all bolts. Loctite on bellhousing bolts, oil pan bolts, timing cover bolts, carburetor flange bolts, driveshaft bolts, water pump bolts, harmonic balancer Bolt. There is only one way to do something. The right way to do it once and be done. It's nothing like doing a job a second time because it's wasn't done right the first time. Or someone else has not done it right and you got to go behind them and do it a second time the right way because they didn't do it right the first time. Wheel studs and lug nuts always get wheel bearing grease on them. Since doing this no stripping galling rusting or any problems. Also on your head or tubes I've never done it but I've seen it done before people cut between the tubes. If it didn't work and leaks after this you could weld it back up and mill it down yourself with an angle grinder medium brown color soft sanding discs 3 inch round pad. Or if it doesn't bother you just leave the weld marks on the headers. Good luck I hope this helps you.
You're brain is in La La Land. These heads aren't even prepped & built. One of the heads is too bad to be used for making the power he's after. And what the hell do ya think is taking place in those heads when they are all completed & strapped onto an engine that is making north of 600 hp. I can assure you there's a hell of a lot more stress going on in there vs "gentle touching/tapping/pointing with an all-thread rod used as a pointer. Good grief man. And do you actually believe he would be doing that with a fully prepped head that is built & ready to torque onto the deck? Get a grip man.
Good info thanks.I think now days it would be hard to find a good heads on the open market.Would it be better to buy a after market head to get a virgin head to start with.
Mark, I have an original never cracked open 1965 425hp 396 from an Impala. Im wanting to run an isky hyd roller cam in it that you use in your builds, 228/238 and punching it out to 427 and dropping to the appropriate comp. Thats all provided a sonic check gives it a pass 962 block of course. Interested in building it? I know its a rectangle motor, whats your thoughts on that build in a 65 impala with an M21 and 3.73 posi running power brakes? I figured it would be a modern interpretation of an l78 turned l72 on pump gas.
You will spoil the value of a rare L78, particularly untouched. Why not get an aftermarket block that's already 4.25"? Sell the engine for big dollars and build a good screamer for the cash.
I have a 396 with the large rectangular ports. Whats the potiential of this engine? Its a 1969 and says HI PERF TRK. I here you can make it a street screamer if done right. Great videos!
I do have a comment/question- I am 62 and rebuilt a 68 427/425 so it had the rect. port heads solid cam, 4 bolt main, etc. Back then there was always discussion/debate about the oval port vs the rect.. granted the rect. heads had the 2.19 intake but just wondering your thoughts
I have a set and I had the intakes ported which was widening and flattening the port floor at the short side radius. They have 2.19 & 1.88 valves which are shrouded by the combustion chamber wall when open so they plunge cut the wall to unshroud the valves which made the prior 98 cc chambers into 100 cc chambers. I put them on a 454 + 0.030” with a Straub spec’ed Clay Smith HR cam 221/235 @ 0.050” and 0.570” lift. Put it in a 4500 lb ‘72 C10 and it will get nasty the instant the back barrels open on the DaVinci prepped 3310 Holley that flows 830 cfm. It annihilates the tires in 1’st & 2’nd gear unless I am running drag radials and they hook. Running flat tops with 0.040” quench and 9.5:1 CR and 40* total timing on 93 octane! Didn’t have the heads flowed but the head guy said comparable work he does usually gets 320 cfm on the intakes.
Do you always use cast heads? Do aluminum heads warp? What is big difference in using cast verse aluminum heads? Thanks Where you learned all this about 454 engines has to have been school hard knocks.
Aluminum a lot more $ for good ones, cast iron ones with the right port work will get you close to the same power to a horsepower point. At that point you will need to go all out with aluminum. Its all about $
Mark, do you feel the Oval port equal to or superior to the Rect. port head? ALWAYS much controversy about that back in the day, they had 2.19 intake, much rarer head though
Would you stick with an 049/781 on a drag strip 427 and make up the compression with the piston? I have some 036 (I think) 100cc closed chamber oval ports, a couple pairs of 781s and a pair of 990's. The biggest off the shelf dome gets me to about 11:1 with a 119 cc chamber. I probably already know what you'll say about the 990's but there is something romantic to me about a rectangle port 427 even if its kind of a slug.
Are you saying the oval port head was superior to the rect. head of the same era? I do remember much debate back in the day over the oval vs rect. head choice but the rect. did have larger intake valve 2.19-- the performance engines did come with the rect. port heads
jim dandy I think the consensus is factory gm rectangle ports are too big for a sub 500ci bbc on the street. They flow ok, but they have low port velocity so not as much air is crammed in at low engine speeds. I've seen a back-to-back test comparing 990s and 781s with 2.19/1.88 valves. the 781s were a few tenths quicker with a 454, 220/220 .500/.500 cam, and a matched dual plane intake and a 4 spees in a 2nd gen camaro.
Keep in mind bigger valves dont flow better unless ported. For example- in a small block 1.94 head, if you put 2.02's in, you will ALWAYS lose some power on the dyno unless you open the ports up. There is a formule for the port size but the hole should be generally 90% of the valve diameter. Not to mention a heavier valve floats sooner if you use the same springs.
Rather than spending time and money to source cores and rebuild them, why not go with aftermarket heads? will you really save much after you pay for the machine work compared to a good bolt-on aluminum head?
If you're referring to stock OEM rectangular port heads, they usually run three times as much as a stock oval Port heads. And then good aluminum rectangular Port heads usually run $1200 on up each. A friend of mine sold me my first big block( we always help each other out with our cars). Had 781 heads already done with 2.25 valves cleaned up, mil down, new Springs new valves already set up for the cam. It was a isky cam everything was fresh on the lower end. $250. Runs really nice. Threw the motor in 1967. Camaro. in front of a T56 Magnum with a 12-bolt in the rear. Normally that head set up would run you about $600 / rebuild. So in my case I would definitely use these heads or on the cheap. otherwise I probably would have went aluminum heads.
@@twinv63 sounds like you are already ahead of the game. Usually rectangular Port heads make more power higher up in the RPM band. Oval Port heads make horsepower and torque in the lower RPM. At least that's what I've read.
What you never mention is what is the cost for all these operations , and you still have not installed guides , did any valve job for the larger valves or even bought any parts. Their are plenty of aftermarket aluminum heads on the market you can buy for the same money you have in this head that is a bolt on. I,m not saying you can,t make the same power with the 781 or 049 head you can , but it just does not make sense investing money in these old heads anymore. After being in the porting business over 50 years and even owing one of the first pairs of Warren Brownfield aluminum heads ever made . It just makes no sense to put this money in these heads anymore
John Lingenfelter could only get around 560 with some pretty fancy head work and whole lot of welding on the intake. So where is the other 60 plus HP coming from.
why would you put the garbage back out for others to come across and have to dump money into ? way to good keeping the garbage out there on craigslist!!
I would assume an even cheaper price would let anyone with a fair amount of knowledge & common sense know that the heads aren't as good as others, don't ya think? Or a disclaimer stating the heads are not well suited for racing, but ok for a work truck. What if someone with very little money is very desperate to get their work truck back up & running........they aren't worried about "racing" at all. But guys like you never consider that, do you. Of course not. The head is only "bad" for trying to make BIG horsepower........beyond what the factory stock engines made. MANY guys use 454 big blocks as a work engine in a work truck ya know........and for that work truck, they could care less about "making 620+ hp". So get a freakin' clue.
Aftermarket heads of any type aluminum or iron sized for the engine will beat any GM Factory Head Hands Down. Aftermarket heads will resell better add to the package in your car reselling it or just selling the motor aluminum heads will sell better than iron heads. Also Factory iron heads vs. Aluminum heads is worth .07 ET in the quarter mile. Because there is a hundred pound difference between aluminum vs Iron heads. And the proof is in the pudding even the cheap Pro Comp aluminum heads make more power than any Factory head. And the front end of the car will come up higher when launching the car with aluminum heads. for better weight transfer on the street or at the track if more traction is needed run aftermarket aluminum heads. Aluminum bolt on ready to go heads make more power and go faster because they are lighter. New heads have longevity and dependability with all new parts is a big plus. Aluminum heads will take higher compression better without detonation on the 10.5 to 1 pump gas. and core shift on Factory heads you will never see it at the track or on the street. And 620 horsepower on a 454 may be possible but it probably is not going to have much torque behind it because the cam will be massive to make this horsepower and will probably be a solid roller with very high compression not streetable. Carcraft did an article with a 502 with 781 heads bigger valves hydraulic roller single plane and it made 520 horsepower and right at 600 foot pounds of torque across the board. And the compression was about 9 to 1 on this combination. So if somebody jumped it up 1.5 point of compression higher it's not going to make a extra 100 horsepower. Anything is possible with 15 to 1 compression, fully ported and Polished iron heads, performance valve job, monster solid roller cam, 1050 dominator carb, single plane tall Ram Merlin X intake, 2 in 1/8 inch equal length headers and 620 horsepower is possible.
So......whats this 620 HP 467 going to run in my 3720 pound 68 Chevelle. Will iron heads keep the front end from lifting? If don't like this build you sure wouldn't like my peanut port build LOL. 9.8 comp 049 headed hyd roller dyno/drag test coming soon..............be there.
VORTECPRO with iron heads on a big block Chevy the front end won't rise as much versus aluminum heads. A 049 head is a big oval Port I have a set I used on an engine build. And it depends on the whole combination weather I would use peanut heads or big oval ports in a project. I personally wouldn't use a square port Old Iron Head unless I was going to sell the engine. The new aftermarket Square Port heads are different I would definitely use those and have. With 10.5 to 1 compression increased cam intake carb headers on the street or strip Square Port aftermarket heads works great. And of course having gears converter and other things matched up. If it was just on the street and the compression was low and just a few steps above a stock cam I would use peanut heads on a mild Performance Engine. But at the track if compression was pretty high good size cam I would run the big oval ports. The funny thing is I seen a lot of guys slow down by over heading or over camming a motor. Especially the the guys at the track that started with big oval ports on a budget and then later back in the day went to a square Port head and slow down at the track. That really hurts to spend all that time and money in a waste of going slower. It kind of makes you feel like a failure. be careful with some of the guys at the track some of them will say they have a square Port head and they really have a oval port. And a lot of them won't really tell people their secrets because they don't want to get out run or someone have a faster elapsed time even on test and tune night. But you can kind of tell with some of those guys that don't know nothing about their engine. I saw a guy run oval Port heads with a square Port intake and do pretty decent at the track. You would think with all that restriction from a square Port intake going into a oval Port head. With his streetcar he ran low sevens in the eighth of a mile not bad. With things not matched to good it is still going to run down the road or track just not as good of course. Remember when I said about the guy that ran the 380 intake runner Square port head GM performance head on the 12.5 to 1 compression 454 in a railcar it slowed down drastically. In the eighth of a mile it's slowed down about eight tenths. That's almost a second slower. That guy felt really sick and he got his heads for free he just picked the wrong cylinder heads. He picked I think the biggest ones in the General Motors book at the time that was a big mistake. That made the Chevrolet dealership locally look bad real bad. But the owner of the rail car with the 454 engine he was a paint and body guy he wasn't much on engine combinations and Technical. he should a fully researched it with a pro guys a lot of engine builders before picking a cylinder head too big and not sure what it would do. There's a lot of very smart and educated guys out there in the field and sometimes opinions will slightly differ. But when picking engine combination power parts it's a little better to go a little conservative than too big. I hope this helps.
VORTECPRO you asked what it's going to run. Not knowing everything else you have converter gears tires and other stuff. I'd be guessing low 7s to Mid sevens in the eighth of a mile.
i would never just bolt on out of box heads! just because their aluminum dont mean they are better. I run 781 heads in 468 with solid roller and 10.3 compression with mahle pistons. the motor makes 690 at 6400 rpm. torque 566@6400. max torque 626@5000 on 91 pump gas.
VORTECPRO I love your peanut port engine project! In my opinion, way too many people think they've already got it all figured out. But you proved that they don't, so many people giving you shit about your stock iron cylinder heads. Saying there's better out there, but it all depends on what type of application, if I'm looking at building a logging skidder, I certainly don't want those giant hog daddy rectangular Port heads! It all depends on the application and I love your peanut Port project engine. Shedding some light on the possibilities for REAL street cars! I like all kinds of engines and applications. But at this point there's too many of these idiots commenting and doggin your approach. They're so narrow-minded all they can think about is 8000 RPM. There's much more diversity then just high RPM Racing Engines. At any rate, I really like your approach and your info. Much respect from me
Did not like the fact that when you said that casting was rough you were going to sell it on Craigslist what is somebody I didn't know about heads was going to buy a piece of crap you're going to sell it to him
