GMC 302 Military engine , running with better sound

A GMC 302 Military engine modified to work in a civilian vehicle. Running commentary by the owner / builder ....me!

[@snowgorilla9789]

What a great job, reminds me of a guy that was building his own boat a he had a big Gardner 6L3 diesel (114 hp @ 800rpm) outside on a stand, when he got frusterated with the boatbuilding he would just go outside and start up that beautiful big engine and just watch and listen then get back to work

[@micahroy9668]

Anyone else surprised at how gnarly the idle sounds?

[@wernerschulte6245]

That´s great !

[@dennisyoung4631]

Yup. It has that *Choptank Idle!* Awesome!

[@lawerencestimpson2280]

Wow very nice build!! Charlie Seabrook had a big Jimmy 6 in a modified roadster.Was a big name at Atco NJ.

[@rayhallas1430]

Absolutely Beautiful thank you for keeping the old iron working - my Dad hauled gas for the 474 fighter group in ww 2 the stories he told about what they put them engine’s through would amaze you - including the stuff they did to get the job done, like crossing a very deep ravine no bridge they laid two big cables across put there spare tires on the front axle so all the wheels had duels - drove across the ravine with the cables between the rims - Dad said it was deep enough that if something went wrong there wouldn’t be anything to salvage - the balls it took to drive across that - Truly a special generation - thank you again

[@jeffbell6211]

Thanks for the kind words. I hear a lot of stories from former military guys and the fond memories of the GMC and the vehicles that they were in.

[@vanlittle5893]

It should pull that Model A around very nicely. I would love to see it when you get it finished.

[@jeffbell6211]

Many thanks to all who have commented. The kind words and encouragement are appreciated. In the future I will be posting a progress video of this engine in the completed chassis of the 1930 Ford Model A coupe .....Stay tuned!

[@johngrepo9976]

Is this block the same size as a 235

[@dougkubash8673]

Years ago I did a valve job on one of these. It was in a 5 ton GMC military truck. Good running engine.

[@jimbos3421]

Nothing beats the sound of a straight 6 !

[@mattlf9120]

Yeah, any V8 lol

[@mikedrown2721]

Maybe the air cooled boxer Corvair 6?

[@ranchurdhimster4955]

I would love to put one of these in a mustang. "Yeah it's got a 302" Edit: Beautiful build btw sir.

[@jeffbell6211]

It would be different to be sure , but they don't have near the HP of a Coyote and they're really heavy too. These engines go way back when flatheads were only 85 -100 HP these big sixes had 160 . Guys coming home from WW2 could get them surplus for cheap and then put them in Model A's like I'm doing. There are still several Bonneville racers using the same engine in XO and XXO class going over 200mph

[@jeffbell6211]

@Russell Gerdes They have been racing the GMC inlines since the early 50's , maybe earlier.There is a vintage engine class in the SCTA that these inlines fit into and they are still competitive setting records at Bonneville and Muroc at over 200MPH. It is common for builders to bore these .125 over and still be reliable. The Chevy's are pushing the limit at .060. Condolences for your brother , thanks for the comment!

[@johnsarab4500]

Love that idle sound!

[@vincej4319]

Awesome classic GMC sound.

[@shandfan]

Driving full trottle in low gear it sounds like a vacuum cleaner.

[@jimkuz27]

That was a good engine, when i first enlisted in 73 my unit had a fleet of 2 and a half ton trucks the 211 deuce! i remember changing head gaskets, water pumps, they had the automatic trans. that took 30 wt. oil, they were called sop a matics,lol. I also had a 49 GMC with a 228 engine, it was a running truck, and i was sorry i sold it

[@KlyfflovesShelby4ever]

Really cool i have a 292 inline and didn't even know they made 302ci engines. Tri-Power set ups are sharp. Im sure you could even supercharge that block like I can a 292

[@jeffbell6211]

The 302 and the other engines in this series (228 ,248 , 270) were several years earlier than the 230 250 292 series. They do make speed parts for these including a supercharger manifold for a 6 71

[@Slim_Slid]

The GMC 302 was used in the GMC M135-M211 2 1/2 Ton Military trucks,which were the first that used 1100×20 single tires,even on the rear,and that had automatic transmissions.All of them got sent to Canada however,because the M35 2 1/2 Ton was what America went with,using non directional tires and a Spicer 3053A and was also a gas truck as well before using a Multi-Fuel engine.Before the two of them,there was the GMC 352-353 CCKW that used a 95 HP GMC 270.The 250 and 292 were used in G.M. trucks years later,and then there was also a 261 which was a bored out 235 basically.The 292 was one of the gasoline engines that even the Chevrolet C60-C70 used as well,the others were the 350,366,427,and even 454,including some with a Detroit 4-53,6V-53,and 3-71,adding the 8.2L in later years.

[@Dayandcounting]

GMC made a 478 v6.

[@robert4005]

Got one just like it myself, had it built several years need to get it running. Beautiful job! Love the sound.

[@jeffbell6211]

Thanks Robert , what are you putting yours in?

[@robert4005]

@@jeffbell6211 eventually a 48 gmc 1/2 ton longbed. That thing ought to make a model A fly!

[@garyquail4996]

Kind of reminds me of an old stove bolt 292 in³ inline 6 that's 1 of my favourite engines.

[@EMDSD40T2]

I've had a couple advanced design Chevy trucks with 216 and 235s. Always liked the inline 6 engines and what you could do with them.

[@HELLBOUNDWARRIORRK]

This Truly is a Work of Art.

[@tonyfreeman5048]

The gmc engines had a sound of their own. Love that sound

[@johnnichols9056]

Nothing smoother than a straight 6 !

[@user-rl9dz1kz2r]

Great exhaust note, and I bet it's a torque monster

[@andyharman3022]

Obviously built with a lot of love. I hope you enjoy driving it for years!

[@CrossStario]

Gotta love the ol’ straight six :)

[@09roushsupercharged26]

Ahhhh, the men of gear heads clan, we meet once again! Great build and thank you for sharing!

[@Karolilalu]

Love when folks keep the sixes alive. One of the best motors ever made.

[@thomremington27]

I drove a "duece& a half" in the early 60's (1953 model) with this engine ..!! ---US ARMY TRANSPORTATION CORPS "GMC M135 TWO AND ONE HALF CARGO TRUCK" ...quite a memory ..!!!!

[@rickwatson1056]

I know it's late to say this but how awesome.

[@cocarr1]

Nice! I've wanted a Jimmy Six for 50 years.

[@brustar5152]

The things you've done to that old girl are just amazing Especially love the tri-power manifold. Maintaining and highlighting the beautiful script of the GMC emblems is brilliant.

[@jeffbell6211]

Thank you Bru Star! I also really like the old style GMC logo

[@b1657568]

And you thought normal straight six's lasted a long time! Very cool build!

[@justmike2944]

Very pretty motor . looks like art to me .

[@pauljanssen2624]

Beautiful engine to build I put one together 2 barrel carb 3 inch exhaust what a smooth sounding engine lot of good power very well design engine I believe the block was only 3 inches longer then the Chevrolet motor the vehicle I put it in with a smooth-running machine able to haul all the big Muffler I put it maybe a very quiet

[@will7its]

Nice, love the manifold...

[@martentrudeau6948]

Great looking engine, sound very nice, it will be great a hot rod.

[@jeffbell6211]

Thanks Marten , I am excited about getting it done. Winter is coming, more shop time soon .

[@tigerseye73]

What a beautiful sound Jeff. Hope your project has turned out to your liking. Thanks for sharing.

[@merlemorrison482]

sounds real good!

[@rd4501]

Beautiful engine, amazing craftsmanship 👍.

[@thomshere]

What a great build and a damn fine looking motor ya got there! I'm sure you could have a second career as a GM military engine builder. Thanks for putting this up because not a lot of people know about these great engines. Hey how about a 9.5-liter GMC “twin six” truck engine next time :)

[@jeffbell6211]

Are you talking about the 600 plus inch V12 with the plaid valve covers that kind of look like 409 covers?....So cool! but very heavy , It would be something in a big speedster like the 'Blastolene" car...I'd take one! Thanks for the kind words!

[@Slim_Slid]

The "twin six" you are thinking about is actually the GMC 702 V12,which is two GMC 351's put into one engine block,and it is actually 11.5L,not 9.5L.Those V12's were used in tracked howitzers at one time such as the M109 Paladin,the other tanks like the M60-M60A3 Patton main battle tank and M88-M88A2 ARV tank retriever had V12's too but they were made by Continental and both were petroleum and diesel,the ones with compression engines came out in 1964.They were 1,790 cubic inches,not 702 cubic inches like the 11.5L V12. The GMC V12 was also popular among many fire trucks,not just G.M. trucks and other apparatus in correlation.The other V12 that fire trucks had was the A.L.F. V12 that American La France Series 700-900 fire trucks used,before they went to using Detroits and Cummins in 1966.The other engines they had was a Continental R330-R883.

[@JasonSmith-vd1sz]

Wow… that’s a work of art!

[@jeffbell6211]

Thanks Jason ,it's been a fun project!

[@Carstuff111]

Ooooof....that look, that sound...... That is beautiful sir!

[@althomas6496]

Sounds great, I have built several hot 6 and 4 engines, like the different.

[@Sheisthedevilyouknowwho-ft9we]

4 inch bore X 4 inch stroke, totally badass. Guys were dominant for a period of time after WW2 racing with these. So they started banning "truck engines" at more and more tracks. That was done to stop people from using the GMC 302 (even the 270 I suppose)

[@A_Cowboy_called_JackRabbit]

Beautiful! Can't wait to see that A! I have a '54 Chevy 2-door post, with a 292 Jimmy in it right now, and it runs STRONG, but my '70 C/10, originally a 307/3spd, now a '67 230, needs one of THESE, with a T56. Thank you for the inspiration!

[@jimthomas777]

Cowboy 919 , my 67 Chevy Truck has a 292 straight 6 and my 68 Chevy Truck has a 307 , The 307 is a 283 block with a 327 crank and the 302 is a 327 block with a 283 crank

[@corvetteZ3r]

Did you have to really modify anything to get that 292 in there?

[@davidnelson4907]

Very nice. I am a big fan of in line engines. Liking the custom intake! This unit would look cool in my 49’ Chevy Styleline. Looking forward to seeing more of your project.

[@turbovan65]

I like the water-heated intake

[@jeffbell6211]

Thanks, I am in Canada and the weather can get cold....I might not need it but it is there in case.

[@Garydigsit]

Love your vintage motor man, super job on it

[@alexpena6948]

Dame it sounds so sweet

[@gordon295]

Super Nice Sound when idling !!

[@revelationakagoldeneagle8045]

A beautiful classic... Sound's Awesome 👍😎 D. Bell 🔔 Georgia, USA ✌️

[@lasalleman6792]

Great custom work; great build.

[@billybell6950]

Nice workmanship! Thanks 😊 for sharing.

[@mobilemarshall]

nice work, beautiful piece of machinery

[@jw4620]

Sweet! It sounds.......polite.

[@johnbehneman1546]

I LOVE IT!!! ROD & CUSTOM 101. Thanks for sharing.

[@hotratz69]

I lost myself when you started that thing.

[@jeffbell6211]

Yeah , I like the sound, too!

[@jeremyderhodes5721]

Oh my god this is a beast

[@pitbull761]

Cómo suena ese Chivo... 💪💪

[@sceneanuerebelrebel9244]

A 64 fifty series Viking GMC ,six cylinder bell housing and four speed box bolt on , flywheel on mine is 40 lb by Mcloed .Salt boys have done really good running super chargers with those short blocks ...

[@jeffbell6211]

Some of my inspiration comes from seeing some of the cars at Bonneville running this same engine.

[@wymple09]

Love that beast.

[@novanut1964]

looks and sounds good, great machine work.

[@grohs775]

love that engine

[@condimentking14]

Beautiful build

[@Duke_of_Prunes]

Smooth! I love that inline sound.

[@shortribslongbow5312]

Sounds great looks awesome outstanding work!

[@paratrooperlane7022]

A work of Art.

[@shaneharrison4775]

Sweet what a beautiful sound and awesome

[@funguy7979]

Man I wouldn't mind that in my sierra

[@christopherprince3250]

That is awesome.

[@jonelliot854]

Motor sounds good

[@jonathansparks7558]

sweet running 6-banger

[@honkie247]

Nothing like the sound of an engine with a long stroke.

[@verothacamaro]

The sweet sound of torque

[@charlesparr3296]

Very beautiful job!!!

[@craigpennington1251]

I'd drop that into a 73 TR 6. I bet this thing's a torque monster. Would sound lovely with those baffles out.

[@hulado]

looks and sounds Great. Thanks.

[@crocbaitaussie5204]

Sounds and looks great

[@Allegronaut]

Nice work & unique sound, good job!

[@dvjracing5947]

Awesome that's for making this video 💪🏻👍💪🏻👍

[@lessparks9388]

That is a great sound.

[@crushingvanessa3277]

Is there a way to make the carbs lower profile? I have a 58 Chev I'd like to get one of these for but with more carb than the one bbl. There's not much clearance under the hood. How much low end torque does this have?

[@jeffbell6211]

The manifold in the video was designed and cast by me. I'm a backyard metal casting hobbyist. I am building a model a coupe with no hood so clearance is not an issue. I do want to try to make a lower profile design at some point but not right now. There are vintage manifolds that come up from time to time at swap meets and eBay. What engine are you running in your Chevy? If it's a 235 or 261 there are more speed parts available for them than for the GMC inlines.

[@MHFtractor]

Sounds awesome 😎 I put a chevy 235 in a farmall bn

[@jeffbell6211]

A 235 in an old farmall!

[@jeffbell6211]

Nice!!!

[@ethanbrown3387]

GMC was never known for their Transmissions. GMC was always known for their engines tho when it comes to engines my opinion they make the best around

[@zanestandlea8368]

Dang I want that intake for my 302 haha

[@tland3900]

Nice work😎👍

[@peanut71968]

Beautiful Beast! Love to see the specs on this, I’d bet torque is almost continuous across RPM’s? Cheers and Thanks!

[@jeromebreeding3302]

That in line in a Model A is going to mean a lot of chopping of the firewall, but an interesting break from the usual flat-head or small-block Chevy.

[@appealingpit]

It sounds very good

[@veraciouspatriot4297]

Awesome!

[@franklinbrown8417]

Sounds great.

[@neiljohnson6815]

It sounds great!

[@PaulThomas-qo9vy]

Sweet Inline 6! Nice job!

[@wuzgoanon9373]

Very cool.

[@dano4572]

beautiful

[@JA-ux7dd]

man that sounds good.

[@jefferyrightmire9520]

real nice

[@baggins1]

Super sweet

[@MrJeep75]

Nice, sounds sweet

[@edwardpate6128]

He says the original bellhousing was for a Turbo-Hydramatic. I think he actually means a Hydramatic which was the old 4 speed cast Iron case transmission. They were very good transmissions.

[@waynekarjala2032]

Reverse was very weak. After we destroyed the trans in the truck we had in the fire dept. We found out we should back up in low range in transfer case.

[@canam851]

Too cool! Love it...

[@MrLrry1266]

Hi, did you cast more parts for the intake. I see a mill in your shop so I think you're more than capable for making the cast tooling. The reason I ask is because I haven't seen an intake quite like yours with the water jacket floor addon. The individual intake castings have to be machined for fit and seal as well as the intake runners. Very nice and your layout skills are obvious as well. Any plans for producing any number of intakes?

[@jeffbell6211]

The intake that is on this motor is a one off that I cast as a prototype. I had a few pattern issues and have since refined the design a bit. I tried to pattern the intake after the McGurk design from the late 40's early 50's. With the exception that I made a removable top . The water heat was an afterthought and I cast two separate hollow blocks with bosses for pipe threads. The only problem I see with this design is the heat is between the ports and not right under the carbs. It should help some but likely won't be as efficient as other styles like the Offenhauser or Fenton. I have no plans for production as of yet , i'm just a hobbyist . I'll keep at it though , you never know. Thanks for the kind words!

[@VinnyMartello]

Its awesome!!!

[@MadsWorld34]

my uncle could build any inline 6 to run and be fast. on dirt track he was hard to beat. but he loved the 292 even built one that would run 9's in the 1/4 mile. i think he could have got into the 8's if he would have went to a automatic.

[@macdoodles5336]

Nice!