I remember flipping through the pages of gm performance parts catalogs in the early 90s and seeing 'raw' heads like this. When chevy actually backed racing, they had all sorts of speed parts that anyone could order through their local dealership. 4.3 blocks that could be built to 320 cubes, raw crank forgings, head castings that were little more than 50lb chunks of aluminum. Now it's all crate engines. Hell, they even had performance junk for iron dukes
Helped guy with an Iron Duke. He bought a used Super Duty head from Jeg's that was off I think a baby Pro Stocker? Also bought 7 six inch small journal Child's & Albert's aluminum rods. The eighth went that a way on starting line. Had to narrow the rods .077" to fit stock crank. Diamond pistons. Ultradyne cam. Crane rockers. I made the oil pan & narrowed the rod bearings. Was in a dirt car. Ran those rods two full seasons. Win one heat race. If he started on poke, would dive to bottom of track and spin out every time. Just never grasped the car didn't/couldn't create enough side bite to run the bottom. Would spin and never stop moving, go high and pass till 3rd or 4th on outside in couple laps then...dive to inside and either spin or door the hell out of somebody. He was an idiot. But I miss him. Cancer sucks.
Hah I was about to say the same thing. I remember seeing magazine articles about the symmetrical port canted valve GM small block heads in the early '90s . I remember seeing a road racing engine with efi velocity stack injection on it. It seems like Katech and Reher-Morrison did a lot of development with this head. It seems like it was an improvement on the Dart Buick heads.
The GM Splayed Head, 358 Pro Stock Truck.. yes around 1100 hp engines towards the end, Jenkins, Pannella were at the Top.. That's a Virgin set, they welded everywhere when they used them in Pro Stock Trucks.. Decks,Inlet Flange,Port floors,Tops of inlet ports to raise inlet runner.. they spent days welding them.. i've see the pics, worked on 1 of those engines here in Australia...Yes crazy HP per cube back then with a modified GM head.. great share Eric...
that canted valve head design for smbc .has been around since the late 60s like late68 -into69 . used to call them porcupine heads for the scca class 302s . my friends dad had those on a 69 z28 ex scca racer it had a cross ram manifold also , special cam , pistons etc. just for that design head. i think if i remember right they were cast by winters foundry gm's go to for their high perf parts castings.
Back in the early 90s I would open up those GM performance parts books and drool all over the bow tie cylinder head section. I’d work all day in a little automotive machine shop and dream of being able to afford a set of any bow tie heads. Several years later I went to work in a machine shop that took car of many different world champion racing engines. The first thing I noticed was bow tie heads sitting on the shelves in the back of the shop. The bone yard so to speak. I’d get myself into quite a bit of trouble pulling those old heads off the shelves marveling over them. The older more experienced guys in the shop would just kind of laugh at me and disregard the enthusiasm I had for them. I’d tried buying them on many occasions never being told a price only the response, “you don’t want those heads, get back to work.” It was disheartening to a degree. Racing season ended and in come all of the engines to be freshened up. That’s when I learned why I was being told I didn’t want those bowtie heads Compared to what was out there getting it done they were junk. There were still about 7 or 8 out of some 40 or 50 engines that had bow tie cylinder heads on them. Those engines always seemed to find their way to the back of the priority list. Toward the end of the freshen up season I learned even more. The owners of those last few were obviously operating on a budget. They has spent so much money developing something that had been great at one point in time. Now they were just doing their best to hang together. I never knew about heat treatment in aluminum until then. The major problem with having these few engines with these heads on them was convincing the owners that it was time to get a new set of heads. I relate to it like telling a long term pet owner their pet had run its course in life. You could show them the hardness test (that was a pretty convincing visual to myself) and the owners would refuse. “Just one more season and we will work it into the budget.” Out of those 7 or 8 maybe two would make it off the dyno without a bad leak down test. Valve seats and guides moving around that you knew were just sealed up as perfect as can be. Head gaskets rattling around, you name it, that problem likely arose. The rest would have to be reworked and re tested. Limp them back off the dyno and maybe a few quick fixes throughout that season. The ones that fell to the wayside went on to that shelf I was always screwing around at. As the years progressed. You see some newer less used versions come in the shop. I never got to see a set that were not compromised in one fashion or another. Most of all I got to see some poor young man with ideas much like what I had that had fell victim to a soft set of aluminum heads that couldn’t be sealed up. Then there was the subject of re heat treating them. That’s a whole other story.
I wonder what would happen if you HIP treated a soft set of heads?. Yea I'm a mechanic by trade, I always tell people, once an alloy head overheats it's better to buy a new head instead of just doing a gasket. It's also why TTY bolts always pull the threads out of alloy blocks, then you need to time sert them.
Also like a Ford Cleveland head first designed in 1968. If you're of the school that the Ford was a knock-off of the Big- Block Chevrolet, Rat engines did not have symmetric ports, had different valve layouts and angles and a different design combustion chamber. Todays LS cylinder heads will bolt-up and function on Ford 351 Small-Blocks without much fuss. (There are even custom camshafts available for that conversion.) Get's one to wonder.
Lol yeah they copied the idea of canting the valves on wedge heads, as the NASCAR rumor goes a gen 2 bbc was sold to ford which is why it took them so many years to come up with a canted wedge of there own. Search up the canted 302 small block Chevy, it was designed before the Cleveland and unveiled before too
Lol yep thats what they are. GM knew a very long time ago the Ford Cleveland head design was superior flow and power. The LS head is a direct descendent of the 4v Cleveland head.
Wrong. It is an exact copy of the big block Chevy cylinder head, that went into production in 1965. The same is true with the LS series of heads. The Cleveland head wasn't even thought of yet in '65.
I bough a 698 BBC Chevy from Tony Christian that look just like these sbc heads. 20 yrs ago. Tony said they were experimental pro stock heads. It runs really good for what it is. Thank you for talking about these heads. Awesome video.
Hi hows it going. I saw your post. And was wondering if your heads had a part number on them . I have a set and been trying to find information on them. They are for a big block chevy
They do have some numbers on them. I live in south Florida and got hit by the hurricane. I moved my car to my father’s steel building. Car is safe but can’t say the same about my house. I will be bringing it home next couple weeks. Thanks for commenting. I’m very curious what they are also
I just saw a post online. Gm have a early pro stock style head. Like the big chief heads thats what I think I have. They made them for the small block also.
Aurora's Pontiac part numbered, open wheeler block used D3 style Ford NASCAR heads. The heads were devised for an 8.2 to 8.45 inch block with 55mm camshaft journals, and that head appeared in AVESCO ( Australian Vee Eight Super Cars) in 1993, and a version of it is still used today in 2022. Bryant made the cranks, Aurora supplied the blocks, GM Powertrain the heads, Bill Miller the pistons, Callie's/ Cariilo the rods, but the Dart cast head porting was free after the CNC profiles and dyno numbers were supplied to AVESCO and Group 3A FIA rules. It was a generic thick casting from which the end user performed the porting.
That cylinder head was used on the Chevy Intrepid GTP road race car around 1991. The Intrepid scored one win in IMSA but, against cars like the 1000+HP Nissan GTP prototypes pretty decent for a 7.0 Litre motor (as I recall)....Sourcing valvetrain hardware for them is a nightmare! T&D used to make rockers + stands for them.....Those fittings might be for water cooling distribution.
I was thinking the same thing. The Indy 500 Buick V6, the "Buick on a Chevy block" for Nascar (also cast by Dart?), the IMSA Intrepid GTP chevy V8, and the Oldsmobile DRCE were all from the same DNA.
@@ray_s281 .....Buick heads were done originally for NASCAR but, they were outlawed they have a shallower valve angle somewhere like 9 degrees, those IMSA GTP heads are 11 degrees as I recall...It's been ages since I was around them....That GTP splayed valve head was offshoot of the Ryan Falconer V6 Indy motor program and the turbocharged Corvette GTP IMSA program (the Falconer V6 IMSA motor exceeded the HP of the Porsche 956/962 GTP variants of the same era, the Lola GTP chassis was abysmal! Bad ground effects and other things, GM teams really had a battle in that Era....Falconer made a V12 motor that was popular in expirimental aircraft with the canted valve heads....The IMSA Intrepid head was refered to as "The Splayed Valve Head".
Is it possible that you could get one of the newer SB2 heads to compare with it so people could understand where it started and where it went to after that
F body production ended in 2002. As for the thread holes by the exhaust ports, if those lead to the water jackets, then most likely it was for port cooling so the exhaust manifold could run cooler and reduce the odds of cracking.
Its a chevy bowtie 45cc combustion chamber. There was a 1st and 2nd design 1first design is 263cc intake runners and 2nd design has 240cc intake runners same valves
Sportsman heads were the bomb at first cause it was all we had as far as cast iron head back then. Well bow tie heads but this were like big bucks. And the big name aftermarket heads. It’s not like today at all. We need a reasonably priced, symmetrical port gen 1 sbc head, shaft rockers, efficiency flow, and they would stomp LS engines. They do have sbc symmetrical port heads, but big money!!
I ran the pontiac heads on my last small block enjoy your post found you totally by accident. I had some of these on my pro stock s10 as well they work well with a full floating full roller set up.
Eric, those holes are for fuel injection nozzles. I am looking at them and they have a 1/2-20 nf nozzle thread. If you look carefully you can see the seats about 5/8 down. The epoxy is covering the hole in the back side of the port. I would bet that if you machine a bushing that threads into those holes with a say, 1/8” drill hole and carefully drilled that you would be 1 drilling epoxy, and 2 you would break through on the intake port on the backside of the valve. Someone else mentioned that this was outlawed by WOO. I believe that was the case, and someone was just trying to save the heads so they could use them. Have you ever tried making an adaptor and putting shop air to them to see if they go anywhere else? Those would be nice on a vintage Supermodified!😂
Hey Eric you are correct. I think the max cubic inch the prostock trucks could run was 360 cu.inch. most ran 358, 357. I followed that series alot when Bill (Grumpy) jenkins got involved and ran a few of his engines in some of the trucks.
They had to have a head made aftermarket because the oe heads couldn't match modded oe Clevelands. Bob Glidden forced GM to do this AND the DRCE because the oe GM stuff couldn't hang with Ford.
Probably because it looks like a shrunk down version of the spread port bbc. Hence little Cheif instead of big Cheif. Your ford fanboy is showing. Nobody cares who came up with it first but who did it best.
@@WeingartnerRacing big chief heads gm copied a head that Larry Olsen built. Larry Olsen is one of the owners at Lsx concepts. If ya want to listen, i would suggest to. DragBoss Garage youtube channel Larry Olsen. That dude has done some stuff.
Big bore destroker small blocks with splayed valves! I remember Chevy and Dodge were flying, don't remember Ford Rangers being that strong. I loved that class also!!
The Ford's were trying to compete with the old C3 head. Ford had designed a new "mirror" head for the class, but it never came to fruition due to the class being cancelled.
Those are down nozzles bosses welded in and plugged in the intake port. You can see the holes drilled to vent the nozzles. The outlaws made a rule when this head comes out that basically said any engine needed to have inline valves.
Hey Eric just wondering how important is the vein. Ive got a set of dart 230 sbc aluminum heads i bought used and have been absolutely hogged out and theres no vein. Im going to use them on a 98mm turbo engine so how will this effect power or will it matter as much with boost.
A good SB2 heads which are similar, flow 420+. I always thought chevy only had the 18* race head at that time for sbc. At least in Nascar early 90s that's what the chevys were using. Mid 90s nascar started running SB2 stuff. I'm not familiar with the drag racing stuff though.
10 years ago we ran 4.34 ci sbc with buick version 10 degree nickan Brothers had done all port work they were from early 90s we bought the complete running motor cam lifters push rods rockers valve covers intake and head studs if you didn't have everything it would pain in ass to put together I belive it was just over 900hp car was under 2200 pounds with driver it would 5.20s in 1/8 mile you still had turn it 7800
I'm almost 100% certain those are the splayed valve heads rather than the sb2 and 2.2 heads...just due to the spread port exhaust because the sb2's still had the siamese exhaust.
Even though the head came out in '91, I doubt there's a port injection intake manifold made for it. You can get a TPI manifold for the Vortec heads, but this was most likely made for a carbureted intake manifold, specially designed to fit this head. There are cheats to make TPI pretty fast flowing and plenty of fresh air storage in the plenum, and they really do well supercharged, but good luck finding a manifold!
Look how big the ports are. It still looks old-school with really square intake ports. Camaro stopped in 2002 model year. There was an overrun on production and there was still new ones well into 2003 at dealerships Edit. Sb2 heads have the same issue with intake port head bolt interference.
Thank you for the valuable details is it still possible to purchase these heads and finished form what is the minimum bore size that these heads will mount on I would appreciate a comment at your convenience thank you
The holes on the exhaust side are maybe for the emission engines? I'm still stuck on the intake manifold, the cam , the timing, and the intake manifold for this head - or is it in the cant of the pushrods?
My understanding was that the 11 deg heads were originally for the Pontiac Nascar program and most of the Chevy teams started using them. Maybe that why it was a "little chief" because Pontiac.
Production spread port heads [both exh/inl.] were being done in Australia in the mid 80`s Went all the way thru to the 2000`s to compete with early gen LS motors , and having excellent dominating success in circuit racing . Unfortunately the aussie v8 was due for a full redesign and the decision was made to oem fit LS to consumer vehicles
The 351C block also shared many similarities with Oldsmobile's Rocket V-8. In conjunction with the similarity of the 351C head to the BBC, it has led to some conjecture that the Cleveland might've been heavily influenced by Semon E. "Bunkie" Knudsen, who defected from GM to briefly run Ford in 1968.
I think it might have been to combat the Ford C3 and Chrysler W3 or whatever in Nascar, because they were able to get 720 out of the canted valve Fords and Mopars, but the most you could do even with the 'pontiac' 15 degree head on a Chevy was about 680 .. a stopgap between the SB2 engines perhaps?
Nonsense on the 15 deg Pontiac which is a Brodix -12P head . You better take another look at the sprint cars of the day and competition eliminator cars too . BOTH FAR Exceeded 680 dude .
@@dougzack4565 the 15 deg head Wasnt Legal Ever for Nascar dude . That 15 deg known as the 328 head(12p Brodix) if memory serves me while the 869 was the one legal for nascar in Pontiac part numbers . Long time ago but it was basically a 10x Brodix if iirc . Theres alot of bs on here for what was what back then . The Fords werent 50hp stouter either back in the day . Aero was the advantage in Nascar for Ford . The head Eric has shown never was a Nascar head either . Drag Racing or big inch mice in GTP Road Racing . They had valvetrain weight issues BAD .
years ago saw a SBC with a set of Cleveland heads and didn't think it was possible, found the bore spacing on a 400 SBC very comparable to a Cleveland head, and the engine had homemade intake and injected
Nascar used that style heads, canted valve like a Ford. V8Supercar also use a downsize version of it. Smaller runners for 5 litre engines. Our Stupidcar engines are all Fords,,, 302 deckheight,shortarse roads, canted valve heads. Some though have bowties on them!!
most of the 357 cube engines made very close power to eachother. I know Jegs was making around the 970hp range when Panella ran the first 7.39 if i remeber on the same meeting Lingenfelter and jegs ran in the 7.3's also. not much seperated them from that point. One of Jegs engine builders I was with, filled me in on the power outputs. it was the best racing as far as I was concerned. Brad Jeter, Larry Koop, Greg Stanfield, Caggnazi and then the Eatons were great to watch as was Patterson. great era shame they got rid of them.
Only been a subscriber for a short while. Did you ever run across the nascar heads somebody was showing around to teams but even though their heads made better power on the top end the flow numbers weren't there on the bench. I understand the bowls were filled so the air did not pile up into the bowl. Since the intake is opening and closing. The tapered former bowl area was less disruptive at high speeds. I have the unfortunate ability to look at and visualize airflow. In 1980 I was sitting in the lobby at cyclone headers. There was a conversation across the room about their prototype AR headers for motorhome 440-3 engines. Changed the airflow enough that the motorhome got 33 mpg. But melted the pistons. Ran great with significant carb tuning changes. 30 years later the tech across the street built a 14 to 1 NA H22 honda for his drag civic. It had horrible reversion in the exhaust. I did a paper towel drawing of an insert to go in at the collector flange. On the mustang dyno. It cranked out 265hp. He slipped the tuning tube in and picked up 10hp. The harshness was gone. It sounded like a healthy big block chevy. A few years after that I was visiting with the new shop neighbor. A 410 winged sprint car. He listened with a glimmer as we looked at his exhaust. But no place for a tuning tube . Then he pointed to the big box on the roof overflowing with sprint car headers. I think he said a dozen sets. But the best top end power set had stepped down primaries. Yes big to smaller.
Hi Wayne, that sounds so familiar !! Somewhere in 2005 I got a Alfa Romeo D2 ( Deutsche Tourwagen Class) 2 liters NA with 310hp on the flow bench. As I already had done some Ford zetecs with 260 hp , Hondas with 285hp on the flow bench I was sure this Alfa head would blow away the previous mentioned heads completely away . How disappointed I was after 1th test: even lower than the Ford zetec , and that was even lower than the Honda with 36.5 mm intake valves . As spare parts of this engine were scarce the engine builder used carrillo lightweight rods and JE pistons to complete a 2th engine. It made 265 hp even with stage 2 cams and headers. Then finally they found the last Mahle piston set available and put in a set of Pankl titanium rods. ( cost 10000 in total) Without ANY other mods it made 314 hp !!!!! Unbelievable to many ..but I watched it hapoen in front of my own eyes...... Edit: the pistons of JE were so tapered that with same squishdistance the pistons rocked so severe hitting the cylinderhead so hard that burrs developed on pistons. So pistonrings couldnt seal perfectly despite gapless Total Seal rings. The carrillo lightweight rods big ends deformed so much that they clamped the bearings , metal to metal contact areas on bearings , on the cranck but flexed back to perfect round when measured......
Recently had a 2019 Nascar head on flowbench . Flow is high , swirl incredible , but flow is not as high as Lsx DR head. With 850 Holley a 5.8 liter makes 900 plus hp. So.. hp is unbelievable!. Low internal friction , efficiënt combustion induction etc. So airflow is sacred.....but not the only holy grail.....
Eric, GM also made big block chevy heads for pro stock racing, part number 10051128. It has symmetrical intake ports to correct the problem of the long leg/short leg runners on the conventional bbc heads. Have you ever played with those? The vortec 8.1 heads go back to that same idea. The fact that gm sabotaged their bbc heads with the good/bad port design is so annoying.. If they had just put 20 more minutes of thought into the head bolt and runner layout, we would not have been stuck with the flawed design ever since.
for sure.... hey Hot Rod I'm now your first Sub... lol Neal Head .... Maryland yeah I've heard all of the "Head" jokes and even made up a few. I've been porting heads since I was a teenager (listening to and learning from guys that may or may not have known jack) I'm 59 now and before I die ,God willing, I'm going to own a flow bench. lol I've always had good results without one though. Peace brother .
Camaro/ firebird stopped in 2002, I was hoping for a new decently looking new model, then heard they aren't no more, but I like a truck anyway, a extended cab short bed, with a minimum 350-400 HP, and be capable of 20-28mpg, it would been awesome if chevy GMC would made a turbo 4.8/5.3 truck with a 6speed option, back in 03 +/-, or a supercharged version, or even a LS-7 truck , with a modified 4L80, 6L90, 3k stall, and twin turbo's😮 3.73(with a optional 4.10-4.30-4.56) gears with 29" tires, and modified rear suspension moving the springs inside the frame, and flared fenders to allow a 305-50-20" , and fit 12" rims with 2"-4" drop suspension, i belive gm would sell tons of these , especially if an awd versikn was available, capable of 305's on all corners,
These were used in NASCAR as a generation 3 head. The sb2.2 was gen 5. On the track as early as 1985. In 1990 they became mail order from GMPerformance.
I would try cutting head bolt towers on top of port & drill hole for socket & put short head bolt in there & make rubber seal plug for intake port just to get rid of head bolt shaft in port! 🤫🤔❓🤷🙋
It's a shame they don't add an extra cylinder to that engine, the could have been selling a new 5.7L 350 V8 for the last 9 years instead of the GenV 5.3.
I agree, looks like a Cleveland head. Oh, by the way, does that Cleveland head look like a big block Chevy head that came out Jan. ‘65. “YUP”, sure as hell does. And what the eff does it matter who copied who?
@@jcoats1203 Yup just like chevy copied Dodge with the canted valve design. I'm just stating the facts that chevy wimps cried so much in Drag Racing about the Cleveland that the NHRA had put the heaviest weight requirements on any car with a Cleveland "to even the playing field". If you don't believe me look it up yourself. It was so bad for you chevy boyz that the NHRA were busting you Corvette guys putting Clevelands in them 🤣🤣🤣 The Cleveland's were also restricted in NASCAR to let you chevy and Mopars keep up. Just like how NASCAR banned the Ford 427 Cammer - made to much power and not even your chevy "mystery aluminum 427 L88" could keep up. Do not think I don't know some history guy "pronoun"??? You are not dealing with some LS scrub here...
Once again, who gives a eff who copied who. Ford had some great engines, Chevy had some great engines, Chrysler had some great engines. Who gives a flying eff, LS scrub?
I know Eric knows but i see many get tied up in flow numbers when it ain't all about how much a head flows. There is more to a badass head than a flow numbers, some high flowing heads are lazy, you wanna make sure you got good air speed and other things but been a long time since I've seen one of these.
@@ldnwholesale8552 I don't know much of anything when it comes to Ford heads. I am a Chevy guy, but I believe it, there are GM heads that are that way.
Hi Eric, thanks for the video, great info as always, I would love to here more about these 1000hp 350ci motors, sounds awesome incredible, I'm guessing they were boosted?
gm version of a cleveland/boss head, no doubt in Aus, they (gm) hit a brick wall with the then current engine rules (5.0 litre) and could not make the power the fords could, siamese intake and centre exhaust ports wouldnt allow sufficient room for fuel injection intake/exhaust primarys - gm teams also got a special short deck block to match the ford motorsport/boss302 to drop the centre of gravity of the engine package (so basically a chev version of a boss302)
