Ford’s legacy of powerful big block V8s dates back to 1958 with the skirted Ford FE Series 332/352ci engines that ultimately grew to 427 cubic inches by 1963 and 428 cubic inches by 1966. These engines were right for the time. The FE went on to win Le Mans, putting Ford in the world’s spotlight with new respect from around the globe.
Enter the Ford 385 Series Engine
By the mid-1960s, Ford product planners and engineers saw the need for new big block engines. They needed to be lighter with a less complicated manufacturing process. Ford took the small block Ford engine blueprint and grew it to big block proportions. The result was the 385 Series family displacing 429 and 460 cubic inches.
Ford took the poly-valve angle design and generous port sizes of the big block Chevy cylinder head and married them to its own traditional approaches to engine design. That made the 429/460 Ford a powerhouse.
Two years into production, Ford introduced the 429 Cobra Jet and Super Cobra Jet and stuffed them in Mustangs, Torinos, Cyclones, and Cougars. It was a natural marriage between a powerful big block and lightweight cars.
The Super Cobra Jet had 11.5:1 compression and was underrated at 375 horsepower and 450 lbs.-ft. of torque. You also got forged pistons, a mechanical camshaft, and adjustable rocker arms. The Super Cobra Jet had a 750 CFM Holley 4150 carburetor on a square-bore iron intake manifold.
We’re at JGM Performance Engineering in Valencia, California for a look at a rare, box-stock 429 Super Cobra Jet build with all the right parts. The Super Cobra Jet has an aggressive cam profile and a choppy idle with the sweet melody of 16 solid tappets thrashing out a beat. On the dyno, our SCJ exceeded factory power numbers thanks to a port job and induction system improvements.
Let’s get started.
We’re working with a four-bolt main “CJ” block. These blocks, as well as four-bolt main Police Interceptor blocks, are virtually impossible to find—and expensive when you can find one. You may perform your own four-bolt main conversion with help from a qualified machine shop and a Milodon kit. (Image/Jim Smart)JGM’s formula for power is simple. Speed Pro forged aluminum pistons and ARP bolts in reconditioned and strengthened rods. These rods can withstand upwards of 500 to 600 horsepower. If you’re going beyond 500, seriously consider aftermarket I or H-beam rods. (Image/Jim Smart)There’s endless debate over how to install piston rings. Some roll them on carefully. Others use an expander. The main concern is not to distort the rings. They must retain their normal shape. Once you have distorted the rings, they will not seal. (Image/Jim Smart)Pistons and rings deserve a generous coating of SAE 30 engine oil or engine assembly lube engineered specifically for pistons, rings, and cylinder walls. Soak the piston and rings with lube as an assembly and slip them into the bore with caution making sure you don’t tag the rod journals below. Bolt caps will protect the rod journals. (Image/Jim Smart)Rod bolts are lubricated and torqued to 40 to 45 ft.-lbs. Check connecting rod side clearances and crankshaft endplay. (Image/Jim Smart)We’re building a 429 Super Cobra Jet with a 3.590 inch stroke. Did you know you can stroke the 429 to 460ci (3.850 inch stroke), a hidden stealthy modification with a 460 crank that will deliver abundant torque without a lot of expense. Summit Racing also stocks a variety of stroker kits that will get you closer to 500ci. (Image/Jim Smart)This is a factory 429 Cobra Jet block with four-bolt mains, which are becoming increasingly harder to find. But there’s a cool four-bolt main conversion kit from Milodon, which can be installed by a qualified machine shop. Always ARP stud your main caps in any case to improve durability. (Image/Jim Smart)Not enough of us do this before degreeing a cam. Find true top-dead-center using a dial indicator before you do anything else. Get the piston to static top-dead-center, then, slowly roll the crank until piston movement is indicated via the dial indicator. Slowly roll the crank both ways watching the dial indicator. Find dead center of the piston movement and you’ve found true top-dead-center. (Image/Jim Smart)We’re running a dual roller chain for precision timing and reduced internal friction. Note the two-piece fuel pump eccentric for reduced internal friction and wear. (Image/Jim Smart)Even if you’re reinstalling a cam, it should be degreed to confirm valve timing events as they would compare with the cam card. Even if you don’t have a cam card, this is information critical to performance and durability. (Image/Jim Smart)The 429 Cobra Jet heads offer generous flow thanks to huge drive-through intake ports. These ports have been cleaned up and port-matched for improved flow. (Image/Jim Smart)The 429’s poly-angle valves are what make this cylinder head rock. They allow for better flow going in and coming out for better scavenging. The Super Cobra Jet with its mechanical tappets and an aggressive cam profile calls for adjustable screw-in studs and guide plates. Standard 429/460 engines have bolt/fulcrum stamped steel rocker arms and a fixed “no adjust” configuration. (Image/Jim Smart)The 385 Series’ 74 – 76cc kidney bean chambers offer excellent quench, which is important to efficiency and power. Be careful about cylinder head selection and look at casting numbers and date codes. Chambers became larger as time went on to get compression down. This is the D0OE-R Cobra Jet head casting with 74 – 76cc chambers and 2.190/1.730 inch intake/exhaust valves. The Police Interceptor casting to come later is similar with larger chambers, which loses compression. (Image/Jim Smart)These huge Cobra Jet intake ports have been ported and massaged to improve flow. They do their best work at high rpm. However, because we’re dealing with a lot of displacement (and stroke) at 429 or 460ci, we’re still getting the torque at low to mid-range rpm. Remember, this is basically a stock 429 Super Cobra Jet, which was factory rated at 375 horsepower and 450 lbs.-ft. of torque. We’re reaching for better. (Image/Jim Smart)JGM studded the intake manifold for spot-on installation. These studs allow the manifold to seat perfectly. Note the modest amount of Permatex’s The Right Stuff around the cooling passage. You don’t need much. (Image/Jim Smart)Exhaust ports were cleaned up to improve scavenging. Ford has never been strong on port sizing—either too small or too large. These exhaust ports needed help. (Image/Jim Smart)The 429 Super Cobra Jet was fitted with a flat tappet mechanical cam from the factory, which calls for valve lash adjustment. Valve lash for the Super Cobra Jet is 0.024/0.026-inch intake/exhaust with valves seated and camlobes on the base circle. If lash seems excessive (noisy), tighten it up a bit to 0.020/0.022 inch. (Image/Jim Smart)When you’re running a dual-roller timing set, do not install the factory oil slinger on the crank, which can get into the chain and do a lot of damage. There’s always a debate on this one, which is more critical with small block Fords. Best advice is not to use it. (Image/Jim Smart)Use only brass or stainless steel block plugs with a thin film of The Right Stuff around the perimeter. Some builders use JB Weld for added security. Do not use steel freeze plugs, which will corrode. (Image/Jim Smart)Because the 429/460 has a generous oiling system, all you really need is a high-volume Melling oil pump and a fresh pickup. Always good to inspect the pump and measure clearances before installation. Check the relief valve’s spring pressure and freedom of movement. Never install an oil pump right out of the box. (Image/Jim Smart)We like the Cobra Jet’s baffled oil pan, which keeps oil where it belongs at high rpm. Summit Racing stocks a variety of high-performance oil pans for drag racing and road racing. Choice depends upon how you intend to use the engine most of the time. (Image/Jim Smart)This crank spacer is common from 1968-78. From 1979 on up, a slide-on counterweight is positioned here for externally balanced 429/460 engines. (Image/Jim Smart)This is the D0OE-9425-C iron intake for square-flange carburetors. Most 429/460 engines were fitted with the spread-bore Rochester Quadrajet. (Image/Jim Smart)This is the more common spread-bore intake manifold for the 429/460. This particular intake manifold is a factory experimental casting (#XE-152211) found in John Vermeersch’s Total Performance shop outside of Detroit. Most 429/460 engines in the 1970s were fitted with the Rochester Quadrajet carburetor. (Image/Jim Smart)On top is a Holley HP Series 750 cfm four-throat, which was optimal for our 429 SCJ. The Holley HP gave us the expected horsepower and torque we were looking for. Horsepower came in at 467.2 hp at 5,700 rpm, with peak torque—480.7 hp rolling in at 4,400 rpm making this a terrific street/strip engine. (Image/Jim Smart)JGM opted for a Pertronix billet distributor, #D132710, for this street/strip application along with Pertronix ignition wires and coil for optimum results. The beauty of the Pertronix ignition is its simplicity and ease of installation. Durability with these Pertronix system along with improved energy makes them a slam dunk. (Image/Jim Smart)Our completed 429 SCJ is quite stealthy with its hotter cam, Crane rocker arms, Pertronix ignition, and Holley HP carburetion. There’s so much you can do here. Opt for the stroke of a 460 for an easy increase in displacement and get all kinds of power your 429 doesn’t have. Stroke equals torque and lots of it. What’s more, no one will know it’s in there but you. (Image/Jim Smart)Comp Cams Multi-Viscosity Break-in Oil with ZDDP zinc additive is what you should use for your engine break-in. It is the zinc additive that protects a flat tappet cam best along with other critical parts trying to seat properly. Zinc aids the work hardening of the cam lobes during the break-in process. Fire the engine and immediately get it to 2,500 rpm for good oil splash and leave it running at that speed for 30 minutes. Although dyno time is not cheap, it is necessary for proper break-in. (Image/Jim Smart)
Jim Smart is a veteran automotive journalist, technical editor, and historian with hundreds of how-to and feature articles to his credit. Jim's also an enthusiast, and has owned and restored many classic vehicles, including an impressive mix of vintage Ford Mustangs.
Comments
27 responses to “Building Ford’s Fabulous 429 Super Cobra Jet”
Back in the day 1964 I recall buying a Ford fast back with the fiberglass hood and the alum bumpers. The engine installed at the factory purchased from my local dealer had a 427 CID engine. My question, do you think/know was this a four bolt main crank engine/block?
All 427 FE.s. Were. Cross bolt mains
Side note the article stated that these are supposed to be lightweight engines the 385 series weight in at 720 lbs
Were the FE 390-427. Were 620 lbs and with a aluminum intake. 550 lbs much lighter than the 385 series
The 385 series engine was not a development of the Windsor small block. It came from a modified MEL block mated with a larger version of the 302 BOSS/Cleveland style head.
It would have been really interesting if the 429 had been developed like a larger version of the SOHC “cammer” engine. Power potential with that block and large unobstructed ports would have been easily over 1000 hp. There were a few aftermarket 4 valve heads offered that gained about 150-200 HP with no other changes on lightly modified engines (I had a friend who gained 10 MPH on a racing boat with a set of ARAO (Dominion) 4 valve heads.)
Actually mains were 4 bolt,cross bolts (side of engine block) make 6 bolt crossbolt mains dezign came about from fords nascar & road racing mostly nascar,on the super speedways under sustained high rpm, running itwide open continuously, the lower end would come apart, There’s a lot of flex moving back and forward believe it or not when an engine’s running like that so after several 100 miles Or a few hours of running that way they would come apart and the bottom ends would explode, This was the fix, a cross bolt main design, after this nascar,lemans all made possible by being able to run 6500 rpm sustained, some say more.?
If you’ve ever taken a Chrysler 426 hemi apart you’ll notice Chrysler copied this feature from this Ford block, Even the Modern modular engines 24 and 3 valve they nicknamed them the baby camera they have a 6 bolt cross bokt design as well..
May be old article ill answer anyway ALL True 427FE engines are easily identified, the bottom of the engine block Near where the oil pan would bolt to there are bolts on the outside that bolt through the block into the main caps,the 427FE is a true 6 bolt “crossbolt” Main engine 428’s,390’s,352’s don’t have that, the 410 or 411 which wasn’t affie that didn’t live long they quickly went to 427 that man had it but the metalurgy is also different.
I owned a 1970 429scj (Torino) when I was 18yrs young. Reading about building one lit my fire of intuition. I’d love to try. I had the Holley 750DP carbonator, on the Shelby intake. The article was more than wonderful for me. If you ever needed 1st hand testimony as to what this underrated HP could do, I’d be one of few that could say, it was a beast. Thanks.
right, but the figure eight design was the weak spot in those motors, tore many 429 s apart, and found cracks in the skirts, a time bomb waiting to explode, the 460 had the straight skirts, no problem with those
In 1974 to 1978 I ran a stock 1970 429SCJ crate engine shoehorned into a 69 Cyclone GT.
Forged Pistons and crank. I beat it up a lot being a daily driver, premium leaded fuel only @ 6 mpg with a stock 3.75 limited slip. I went through about as much cash in tires as gas but she went over 90,000 miles with Mobil 1 synth. without a prob except had to set the valves every 2-3 wks . Feeler and wrenches in the console! FYI never heard of any piston probs with them but then again I would never beat it up cold.
With every engine gas or diesel, I always let them warm up a bit. The denser the material, (forged pistons) warm up is more critical, it’s kind of common sense.
The 460 marine engine was available with an 8to1 cast piston,320hp @ 4600rpm or FORGED 9to1 TRW piston,340hp @ 4600 rpm. The Holley flange cobra jet manifold was utilized for the marine 460 and gave an additional 10 hp @ 4600rpm over the stock manifold ( even with terrible port mismatch of the smaller cylinder head intake ports). The marine engine performed well in the 1971 to 1973 heavy Mutangs buzzing to 5500 rpm with the marine cam. The heads choked the rpm levels.
I had a 1990 jet boat with the forged piston 340 hp. I replaced the cast iron intake with an Edlebrock dual plane aluminum and it improved low end performance quite a bit. My pump kept the rpm so low (4200) that the huge runners of the CJ intake did more harm than good.
I had a 1970 torino super cobra jet 429 ram air what was special it had bench seat an rubber floor no carpet. I was only 18 when I got it .now every time I think about it which is everyday I cry for selling it it was yellow an black I have a diecast model of it that set right in front of me at home. Love my fords
Anyone ever flowed the 429 factory SCJ Holley intake on a flow bench to see what CFM it flowed? Just wanting to compare it to say the Weiand Stealth 8012, the PERormer RPM and Torker II intake manifolds.
I haven’t but I looked at some of the dyno charts it’s amazing that factory heavy castiron intake seems to be the best low mid range torque setup for truck applications or slightly modded street engines, when swapped out right away it loses low and mid range torque not a little but 30-50 ftlbs below 3500 rpm and picks it all back up on the topside, but thats the sweet spot. I’m going for ford performance or AFR heads, street torque,3/ton, 4×4 truck 400 to 450 hp. 500 torque, hopeful guesstimation build, i cant wait fir the power and the 4 to 6 mpg.LOL
Have (7) TRW L2366 .030 pistons on C9VE-A rods here. Am told #8 exited the block violently. Are these CJ or SCJ pistons? No use for them….. any interest?
The engine had symmetrical port heads that required an intake manifold that had extreme bends to feed each cylinder equally.
The engines with “paired ports” had more efficient intake manifolds.
The distributor was mounted at the front of the engine which also put the oil pump at the front of the engine. The oil pickup tube extended to the rear of the engine and would pull the oil forward against the gravity forces of an accelerating vehicle. Paired intake ports and rear mounted oil pumps were the way most automotive engineers would build engines in the 60’s.. Ford was always weird.
In 1970, K26 (k = November 26) Ford had a habit of mixing and matching engine blocks on the machining line. This was due to “on loading and off loading” skids of blocks. The lines were mixed with different castings that were not all finished the same style occasionally. Ford was not about to “clean out the line” to change from the CJs to the 2 bolt non-CJ blocks, so some of the CJ castings ended up machined as 2 bolt blocks. Just the same, some “A” thick bulkhead CJ blocks were machined the same way. Since it cost basically the same to make a standard, CJ or “A” block, Ford wasn’t too concerned about a few CJ blocks going out as 2 bolt main standard 429s. For example, the machining line would get an order to run 500 to 1000 CJ or SCJ blocks and in the process of the approximately 25 progressive “operations” from the beginning “broaching” to the finish “honing to size” of the cylinder bores to match the piston order, blocks went on and off the line depending on back ups or delays. The run would be made while some of the CJ blocks were partially machined on skids.
Thats how even a 2V 1970 429 Mercury Marquis engine could have come with a CJ block. Ford would not let the reverse to happen or they might have been sued but the Mercury owner is not going to complain about having a high-nickle, thicker, 4 bolt main ( three center caps) engine block. The same scenario was possible with the Clevelands, 4 bolt block in a 2V production 351C. Seen that one too!! The blocks are all relatively cheap for Ford to produce by the time they get to end of the machining line.
Back in the day 1964 I recall buying a Ford fast back with the fiberglass hood and the alum bumpers. The engine installed at the factory purchased from my local dealer had a 427 CID engine. My question, do you think/know was this a four bolt main crank engine/block?
All 427 FE.s. Were. Cross bolt mains
Side note the article stated that these are supposed to be lightweight engines the 385 series weight in at 720 lbs
Were the FE 390-427. Were 620 lbs and with a aluminum intake. 550 lbs much lighter than the 385 series
The 385 series engine was not a development of the Windsor small block. It came from a modified MEL block mated with a larger version of the 302 BOSS/Cleveland style head.
https://autohistorypreservationsociety.org/ford-385-series-v8-explored/
The engine was a good setup especially the NASCAR BOSS 429 having a reliable bottom end and the ability to tune for considerable extra power.
https://www.youtube.com/watch?v=7Bp1tjQA69M
Today oversize block engines based on the 385 design are making over 1200 hp
https://jonkaaseracingengines.com/product-category/engines/
It would have been really interesting if the 429 had been developed like a larger version of the SOHC “cammer” engine. Power potential with that block and large unobstructed ports would have been easily over 1000 hp. There were a few aftermarket 4 valve heads offered that gained about 150-200 HP with no other changes on lightly modified engines (I had a friend who gained 10 MPH on a racing boat with a set of ARAO (Dominion) 4 valve heads.)
All 427 Ford engines are cross bolted. 2 bolts are verticle and 2 bolts are horizontal through the block skirt except the front and rear main caps.
Actually mains were 4 bolt,cross bolts (side of engine block) make 6 bolt crossbolt mains dezign came about from fords nascar & road racing mostly nascar,on the super speedways under sustained high rpm, running itwide open continuously, the lower end would come apart, There’s a lot of flex moving back and forward believe it or not when an engine’s running like that so after several 100 miles Or a few hours of running that way they would come apart and the bottom ends would explode, This was the fix, a cross bolt main design, after this nascar,lemans all made possible by being able to run 6500 rpm sustained, some say more.?
If you’ve ever taken a Chrysler 426 hemi apart you’ll notice Chrysler copied this feature from this Ford block, Even the Modern modular engines 24 and 3 valve they nicknamed them the baby camera they have a 6 bolt cross bokt design as well..
May be old article ill answer anyway ALL True 427FE engines are easily identified, the bottom of the engine block Near where the oil pan would bolt to there are bolts on the outside that bolt through the block into the main caps,the 427FE is a true 6 bolt “crossbolt” Main engine 428’s,390’s,352’s don’t have that, the 410 or 411 which wasn’t affie that didn’t live long they quickly went to 427 that man had it but the metalurgy is also different.
Please excuse the spelling my phone likes to correct me after I write hope you can understand it
every 427 block iv ever seen had the cross bolt mains, making it 4 bolt main
I owned a 1970 429scj (Torino) when I was 18yrs young. Reading about building one lit my fire of intuition. I’d love to try. I had the Holley 750DP carbonator, on the Shelby intake. The article was more than wonderful for me. If you ever needed 1st hand testimony as to what this underrated HP could do, I’d be one of few that could say, it was a beast. Thanks.
The 71” 429scj came with forged pistons
right, but the figure eight design was the weak spot in those motors, tore many 429 s apart, and found cracks in the skirts, a time bomb waiting to explode, the 460 had the straight skirts, no problem with those
In 1974 to 1978 I ran a stock 1970 429SCJ crate engine shoehorned into a 69 Cyclone GT.
Forged Pistons and crank. I beat it up a lot being a daily driver, premium leaded fuel only @ 6 mpg with a stock 3.75 limited slip. I went through about as much cash in tires as gas but she went over 90,000 miles with Mobil 1 synth. without a prob except had to set the valves every 2-3 wks . Feeler and wrenches in the console! FYI never heard of any piston probs with them but then again I would never beat it up cold.
With every engine gas or diesel, I always let them warm up a bit. The denser the material, (forged pistons) warm up is more critical, it’s kind of common sense.
The 460 marine engine was available with an 8to1 cast piston,320hp @ 4600rpm or FORGED 9to1 TRW piston,340hp @ 4600 rpm. The Holley flange cobra jet manifold was utilized for the marine 460 and gave an additional 10 hp @ 4600rpm over the stock manifold ( even with terrible port mismatch of the smaller cylinder head intake ports). The marine engine performed well in the 1971 to 1973 heavy Mutangs buzzing to 5500 rpm with the marine cam. The heads choked the rpm levels.
I had a 1990 jet boat with the forged piston 340 hp. I replaced the cast iron intake with an Edlebrock dual plane aluminum and it improved low end performance quite a bit. My pump kept the rpm so low (4200) that the huge runners of the CJ intake did more harm than good.
thank u first on race day
I had a 1970 torino super cobra jet 429 ram air what was special it had bench seat an rubber floor no carpet. I was only 18 when I got it .now every time I think about it which is everyday I cry for selling it it was yellow an black I have a diecast model of it that set right in front of me at home. Love my fords
Anyone ever flowed the 429 factory SCJ Holley intake on a flow bench to see what CFM it flowed? Just wanting to compare it to say the Weiand Stealth 8012, the PERormer RPM and Torker II intake manifolds.
I haven’t but I looked at some of the dyno charts it’s amazing that factory heavy castiron intake seems to be the best low mid range torque setup for truck applications or slightly modded street engines, when swapped out right away it loses low and mid range torque not a little but 30-50 ftlbs below 3500 rpm and picks it all back up on the topside, but thats the sweet spot. I’m going for ford performance or AFR heads, street torque,3/ton, 4×4 truck 400 to 450 hp. 500 torque, hopeful guesstimation build, i cant wait fir the power and the 4 to 6 mpg.LOL
Former Ford engineer! your pretty close but about perfect… I have still have a few of the SCJ motor laying around… If needed
Thanks George 460
Are Your 429scj’s still available?? Would be interested if so but I know your post is older. Please shoot me an email. Thank you. Mike
Hey George Ingram ,I would love to talk to you about your SCJ’s! Ken A. Leave me a message so I can reach you !!
Have (7) TRW L2366 .030 pistons on C9VE-A rods here. Am told #8 exited the block violently. Are these CJ or SCJ pistons? No use for them….. any interest?
The truck 88-96 heads, can anything be done to make some power economically? Looking for more torque than upper ram as it’s a truck engine.
The engine had symmetrical port heads that required an intake manifold that had extreme bends to feed each cylinder equally.
The engines with “paired ports” had more efficient intake manifolds.
The distributor was mounted at the front of the engine which also put the oil pump at the front of the engine. The oil pickup tube extended to the rear of the engine and would pull the oil forward against the gravity forces of an accelerating vehicle. Paired intake ports and rear mounted oil pumps were the way most automotive engineers would build engines in the 60’s.. Ford was always weird.
Regarding the engine as built in this story: What rating of gas is required to run this motor without damage? Thanks, blakewoith@yahoo.com
Hey, I have a 429 1970 K 26 and is it in the valley is CJ but it’s only two bolted main is that a good block
In 1970, K26 (k = November 26) Ford had a habit of mixing and matching engine blocks on the machining line. This was due to “on loading and off loading” skids of blocks. The lines were mixed with different castings that were not all finished the same style occasionally. Ford was not about to “clean out the line” to change from the CJs to the 2 bolt non-CJ blocks, so some of the CJ castings ended up machined as 2 bolt blocks. Just the same, some “A” thick bulkhead CJ blocks were machined the same way. Since it cost basically the same to make a standard, CJ or “A” block, Ford wasn’t too concerned about a few CJ blocks going out as 2 bolt main standard 429s. For example, the machining line would get an order to run 500 to 1000 CJ or SCJ blocks and in the process of the approximately 25 progressive “operations” from the beginning “broaching” to the finish “honing to size” of the cylinder bores to match the piston order, blocks went on and off the line depending on back ups or delays. The run would be made while some of the CJ blocks were partially machined on skids.
Thats how even a 2V 1970 429 Mercury Marquis engine could have come with a CJ block. Ford would not let the reverse to happen or they might have been sued but the Mercury owner is not going to complain about having a high-nickle, thicker, 4 bolt main ( three center caps) engine block. The same scenario was possible with the Clevelands, 4 bolt block in a 2V production 351C. Seen that one too!! The blocks are all relatively cheap for Ford to produce by the time they get to end of the machining line.