Odd engine combinations and how did they work.

[340dartley]

I was remembering a motor I built in when I was in college that ran way better than it should have. I figured I would open up a discussion on the topic. It is fun to me to find out what other people did and their experiences.

I was taking an automotive class in college and for my project I built a 340 short block. I had a 1967 Dodge Dart with the original 273 that was rebuilt and ran good enough. It always lacked low end torque but would Rev to the moon. It had a solid lifted crowed cam with. 488 lift. I ran an old edelbrock LD4B intake with a Carter afb. It also had a good set of hooker headers. It had dual 2.5 inch exhaust with flow master mufflers.

Well because I was 19 years old and the car lived between 6000 to 7000 rpm to make power, the motor did not last long.

I ran it at the drag strip with best pass in the high 15s. I did put nitrous on it once and clicked off a 13.9. It had anopen 3.23 geared 8 3/4 rear axle.

Well I wound up spinning a rod bearing eventually and the motor broke a rod.

I had been building my 340 in class and it was. 030 over short block from 1974. I put a 1969 steel crank in it. Stock cast 10.5 to 1 Pistons. I bought an Erson TQ30 cam and lifters. When the 273 blew up I was forced to swap engines as the car was also my daily driver. I did not have any 340 or 360 heads for the motor so I took the top end off the 273. Small valves, small ports, small intake.I figured the increase in size and compression should give me a little more power than the 273 even though the heads won't flow enough to make big power. I worried about the 10.5 to 1 Pistons with open chambers being bolted to closed chamber heads..

The end result was a monster of a motor. After I broke in the cam, I took it for a short test drive. WOW I gave it gas like I normally did when I drove it and it left 50 feet of rubber. I pulled into an abandoned parking lot and launched it. The tires spun until you let off the gas.

Only downside was it ran hotter and when it was hot it wouldn't shut off. I had it over heating once and brought it up to the house and turned the key off. It was still idling on all 8 cylinders. I pulled the coil wire. It still ran good. I could still Rev it up. I had to choke it out with a shop rag.

It ran 13.8 on motor. I eventually got some 360 heads but it never was as powerful as it was with the small port heads.

 

[moper]

I had some. First was a 318 shortblock that replaced a 340 short that I broke. I pulled everything off of the 340 including the cam (I detonated some ring lands off the pistons) and stuck it all on the original 100K plus '74 shortblock. Aside from a little loss or power right of idle (4sp E body with 3.23s) there was no difference between the two. That was based on street racing I was doing at the time, not track times. But the car never really fell off.
2nd was a 440 I did for another car. Machined and all new parts. Basically a stock '69 440 with some home ported heads (I was in my teens - so admittedly a bit before I knew very much) and an MP .528 solid. In an E body auto it went 12.1 at 117mph. It was incredibly torquey. That surprised me as it was my first experience with the .528. Well any solid lifter cam to be honest...lol.
A 340 with poor machining and some miles, a top end thrown together with some decent heads and hydraulic Comp cam. Once the car was somewhat debugged it went 12.0s. Horsepower was figured around 460. That surprised me.
A 422 I built for a customer. Still running and with 12K or more on it - by MPH makes about 470hp with the Eagle cast crank (last one I used), gets high teens for gas mileage, runs factory rods an factory ported iron heads.
A 496 more recently built for a customer. Smaller solid flat tappet, ported Stealths, factory exh manifolding an exhaust dyno'd at 450hp at the tires. As he bolts on more speed parts it keeps showing more power. It stil is surprising me...lol.

 

[Dr dan]

I hope you'll accept a non mopar build:
Back in the 70's I was running roundy rouders on the local dirt 1/4 mile, the class was "hobby stock" and was being dominated by a guy with a 250cu.in. chevy with duel carbs. and a modified power glide. Six cylinder motors were given a lot of leeway on the stuff they could do. I decided he needed some competition so began to figure out what I could do with a /6 as I was, even then a mopar guy. I got scared out of that build by the wienie arm crankshaft and lack of main bearings. I was sure it wouldn't last.
So I went to a 300 cu.in. Ford. It wound up with some sort of tractor pistons that had the right pin location to make 11.5 comp. with a head off a 240 that was ported and larger valves installed. I built my own intake manifold to hold 3 weber sidedrafts. I also built the adaptor to use a modified (no torque converter) powerglide. That was new tech back then. The first night out the driver (not me) timed in third quick so he started near the rear of a 20 car field and went to the front in 10 laps, got tangled up with a slower car and did it again before the engine blew a head gasket with about 3 laps to go. several weeks later. after "O"ringing the block. the rules changed and multiple carbs were outlawed. That was the death of the six cylinder dynasty. I wish I'd kept the engine, would have been great in a ratrod.

 

[RustyRatRod]

I remember back in the late 70s and early 80s the first thing we did was 4 barrel, headers and a BIG cam in an otherwise stock engine. Those engines ran better than expected, though.

 

[nm9stheham]

It ran 13.8 on motor. I eventually got some 360 heads but it never was as powerful as it was with the small port heads.

Probably the compression went into the toilet with the large chamber heads. Some people poo-poo compression ratio but are only looking at peak HP numbers. CR drives combustion pressure, particularly at lower RPM's, and that is what makes torque.... which launches a car and makes it jump out whenever ever you hit the throttle over a wide RPM range.

The combo I built that so many would say is wrong was a 351C in the 70's: 10.2 SCR forged with quench, 2 BBL 351C heads (that flowed stock like Edelbrock Performer SBM heads flow out of the box), 1-7/8" tube headers into 3" collectors and a Torker 1 single plane. Most folks would tell you it could not run at low RPM with all the large breathing parts, but the key was a torque/mileage cam and a 600 cfm, vac secondary Holley. Cam was 190/200 degrees at .050" with lift of .445/.470 and a 114 LSA. Good torque across a very wide RPM band and would rev to 6500 before the optimum shift point was reached: the large breathing parts seemed to compensate for the small cam at high RPM's and the cam seemed to compensate for the large flow parts at the lower RPM's. It would beat stock 440 Mopars B bodies off the line and in a 1/8 mile distance all day long and most everything else on the street, with a stock TC and a low 3's rear axle ratio, and then get 19 mpg on the interstate. Towed a small race car with it across most of the US east of the Mississippi. A true 'engine for all seasons'.

 

[nm9stheham]

So I went to a 300 cu.in. Ford. It wound up with some sort of tractor pistons that had the right pin location to make 11.5 comp. with a head off a 240 that was ported and larger valves installed. I built my own intake manifold to hold 3 weber sidedrafts. I also built the adaptor to use a modified (no torque converter) powerglide. That was new tech back then. The first night out the driver (not me) timed in third quick so he started near the rear of a 20 car field and went to the front in 10 laps, got tangled up with a slower car and did it again before the engine blew a head gasket with about 3 laps to go. several weeks later. after "O"ringing the block. the rules changed and multiple carbs were outlawed. That was the death of the six cylinder dynasty. I wish I'd kept the engine, would have been great in a ratrod.

This is great stuff! LOL

 

[RustyRatRod]

Probably the compression went into the toilet with the large chamber heads. Some people poo-poo compression ratio but are only looking at peak HP numbers. CR drives combustion pressure, particularly at lower RPM's, and that is what makes torque.... which launches a car and makes it jump out whenever ever you hit the throttle over a wide RPM range.

The combo I built that so many would say is wrong was a 351C in the 70's: 10.2 SCR forged with quench, 2 BBL 351C heads (that flowed stock like Edelbrock Performer SBM heads flow out of the box), 1-7/8" tube headers into 3" collectors and a Torker 1 single plane. Most folks would tell you it could not run at low RPM with all the large breathing parts, but the key was a torque/mileage cam and a 600 cfm, vac secondary Holley. Cam was 190/200 degrees at .050" with lift of .445/.470 and a 114 LSA. Good torque across a very wide RPM band and would rev to 6500 before the optimum shift point was reached: the large breathing parts seemed to compensate for the small cam at high RPM's and the cam seemed to compensate for the large flow parts at the lower RPM's. It would beat stock 440 Mopars B bodies off the line and in a 1/8 mile distance all day long and most everything else on the street, with a stock TC and a low 3's rear axle ratio, and then get 19 mpg on the interstate. Towed a small race car with it across most of the US east of the Mississippi. A true 'engine for all seasons'.

The key to that Cleveland's performance was the heads. The early 2V Cleveland and 400 heads had very good ports. But I would have to ask.......how did you get quench with an open chamber? A domed piston no doubt?

 

[nm9stheham]

The key to that Cleveland's performance was the heads. The early 2V Cleveland and 400 heads had very good ports. But I would have to ask.......how did you get quench with an open chamber? A domed piston no doubt?

Correct and very perceptive, sir. They were special TRW domed pistons designed with a 'quench dome' on the spark plug side that came up very close to the stock chamber wall on that side, and a slot in the dome for the flame front to pass through. One of the claims made was that the quench air 'squirt' would push the flame front out faster and help the combustion process. The designed CR was over 11, but I ground out the other side of the chambers some to get the CR down to the low 10's for pump gas, and CC'd them all. I dunno how good the quench was, but the engine ran without detonation on pump gas, and the DCR had to be up in the mid 8 range with that cam. (60 degree ABDC intake closure).

The Clevelands and boss motors were also helped with a stock 1.73 rocker ratio; you could get gobs of lift with low duration. That was one of the first thing I learned here about the SBM: the 1.5 stock rocker ratio drives you to use longer durations and thus higher RPM's and higher stall TC's and rear gears. All just due to a seemingly minor design difference.

It was all a pretty good training ground for a 21 year old aspiring gearhead.... the engine is still in the garage.... temptations abound....And its the pattern for what we are doing with my son's 340: We're going with 1.6 rockers just to get some of that higher lift-to-duration ratio back....as well as working for 10:1 SCR and quench.

 

[rumblefish360]

I remember back in the late 70s and early 80s the first thing we did was 4 barrel, headers and a BIG cam in an otherwise stock engine. Those engines ran better than expected, though.

They normally do. Even a low compression engine will respond well to better breathing equipment. Adding a cam helps so long as it doesn't decimate the static compression ratio. Bowl ported heads always helped as well. Fully ported ones killed the stock short block engines.

That '79 smog 318 I did years back even worked well for what was thrown at it. A stock 2bbl. engine doesn't do so great in the 1/4 mile run and no one even looks twice at it. After adding a few parts and a cam, many wanted to try it out.

OOTB test, 15.14 @ 89. Not a house burner by any means. It was whittled down to the high 14's. Almost a 340 time. Good mileage and some umph.

 

[Dartnut]

Back in the early '90s, my brother bought a ratty '70 Challenger body and wanted to get it running as cheap as possible.
We got a old demo derby '69 Newport with a 383 2 barrel, and changed the cam to a well used street hemi grind one that we had laying around with mix and match lifters, used timing chain and gears, the intake and avs carb off of my '69 Super Bee, a noisy and badly worn set of 3:55s with a sure grip, junk headers and exhaust that were literally taken out of the scrap pile.
Total investment for the whole project was $400 for the body, the engine, transmission, and gears were free, the other parts were used and discarded (so free), he bought a new oil filter and oil, and reused or made new gaskets. All ignition parts were used and didn't look great. The car ran okay, but it did have a weak cylinder.
However, it ran 14.20s in the quarter mile at Spokane, and he installed a used 10'' converter for $25 and it ran 13.73 @ 102 mph.
I doubt that he had more than $500 in the whole car, and it ran good for 3 years like that until he sold it.

 

[RustyRatRod]

Correct and very perceptive, sir. They were special TRW domed pistons designed with a 'quench dome' on the spark plug side that came up very close to the stock chamber wall on that side, and a slot in the dome for the flame front to pass through. One of the claims made was that the quench air 'squirt' would push the flame front out faster and help the combustion process. The designed CR was over 11, but I ground out the other side of the chambers some to get the CR down to the low 10's for pump gas, and CC'd them all. I dunno how good the quench was, but the engine ran without detonation on pump gas, and the DCR had to be up in the mid 8 range with that cam. (60 degree ABDC intake closure).

The Clevelands and boss motors were also helped with a stock 1.73 rocker ratio; you could get gobs of lift with low duration. That was one of the first thing I learned here about the SBM: the 1.5 stock rocker ratio drives you to use longer durations and thus higher RPM's and higher stall TC's and rear gears. All just due to a seemingly minor design difference.

It was all a pretty good training ground for a 21 year old aspiring gearhead.... the engine is still in the garage.... temptations abound....And its the pattern for what we are doing with my son's 340: We're going with 1.6 rockers just to get some of that higher lift-to-duration ratio back....as well as working for 10:1 SCR and quench.

The Cleveland was Ford's most overlooked engine, IMO. I have the heads for my 400 in the shop now. I cannot wait to see how it pulls, because this 351M pulls like heck right now and it's bone stock. I often wonder why Chrysler never tried a canted valve head on the big and small blocks.

 

[twayne24365]

Dads 65 coronet had a stock 65 2 barrel 383, put a 528 cam, street dominator intake, 850 Holley, and headers. Car ran 12.65...like rusty said, bigger cam, headers, and carb with no compression. But it worked

 

[pishta]

I spun a rod on my 273-4 so I yanked it all and put everything into a 318 short block. ran harder than the high compression 273-4. Oh, and I had a 351C with a 4bbl Offy intake and an Erson Hi-flo 2 cam with headers in my 57 Ford, darn thing ran like a scalded cat. I remember out hustling a 70's 350 Camaro on the freeway from about 60 to 90. We kept prodding each other on about a 40 mile stretch of I-5 back in the day. It was a little soft off the line though. The 4bbl heads that my buddies 351-C mustang ran were untouchable after about 4000 RPM but were not good below that.

 

[69 Cuda 440]

1964 Oldsmobile F-85

Year ..... 1972

We stuck a Pontiac 421 'Tri-Power' in the Olds from a wrecked 1966 Pontiac 2+2,
with an Automatic Transmission

Installed a set of 3.90 Gears in the Oldsmobile Rear, with an 'Anti-Spin' set up.

We were able to 'finagle' a set of Headers on the car. How, I can't remember.

We threw on a set of Goodyear 8" x 27" Slicks on 15" Rims.

When we got to the Drag Strip, we claimed it was a '389', and they classed
us in C/Gas.

Blasted that car to ........................ 13.10's @ 108 MPH.

'Bad Hiney' ............ The Rear-End came apart after 5 Runs.

 

[moper]

Sounds like the Don Paparian days. He used to race those big Pontiacs in the 60s and into the 70s. Street raced and at CT Dragway.

 

[Marcohotrod]

1973 dart sport with a $90 1968 318 and a 500 afb and an edelbrock steetmaster and 360 exhaust manifolds and f70 tires smokes a 350 Camaro with headers and chrome valve covers and g60 tires

 

[Krooser]

I'm looking at a 396" SBM right now for my dirt late model. Needs a bit of work… been parked for 20 years… but it's loaded with good parts and deserves another shot at Saturday Night glory….

 

[65Val]

..... smokes a 350 Camaro with headers and chrome valve covers and g60 tires

Those chrome valve covers musta been why that Crapmaro was fast!....LOL

 

[hemichuck]

Back in the 80's I bought a guys 1963 Dart project for $600 and it came with this 340 that had been bored .060 and had TRW 12.5 domed Pistons with stock 340 rods and forged crank. The short block was balanced and pretty stout but the top end is where things got weird. It had a set of 273 HiPo heads that had been ported all the way into the water jackets and pushrods holes and Devconed over. The cam was an old Crane Zip 518 solid that was 518 lift and 265 duration @.050. It came with a tunnel ram which I dumped for an Edelbrock Torker and a Holley 750 double pumper. It ha 1 5/8 fender well headers and it also had a B&M manual valve body and 10 inch converter. That was hooked to an 8 3/4 with 5.70 gears and a 10.5/ 28 slicks. In the eighth mile it would run 7.70 all day and night. It would rev to 8000 but had no power after 6200 rpm. The thing had such a crisp exhaust note it sounded like a top fueler. I drove it to the track one weekend and we made 64 passes without doing anything to the car but adding gas. 5 different drivers and it ran between 7.70 and 7.90 every run