The Venerable Slant 6 vs Our Beloved Flathead 6s

[Xlarashun]

On 1/30/2018 at 10:10 PM, keithb7 said:

When I was about 16, in Grade 10 I bought a 1976 Dodge Dart. If I recall it had a 225 slant 6 engine in it. My Father was dead set against me buying any "P.O.S. import" he called them. North American built or nothing at all, I remember him saying. I spent what seemed like forever trying to find a car that Dad approved of. Finally I settled on the Dodge Dart. He gave it his blessing after going over the car with me. Within a few days I noticed it was hard to start when it was hot. It would crank fast but never start until it cooled down again. Dad was no mechanic. He had no idea what to do. I was new to cars but my brother who was 18 at the time in Grade 12, was totally a gear head. He was planning to be a heavy duty mechanic. 

 

Bro and I spent a couple of days troubleshooting together. We had few specialized tools. Finally we begged and borrowed a compression tester. Yup low compression across all 6. We quickly made a decision to pull the engine and rebuild it. Ourselves. In the back yard. No garage. We borrowed an engine hoist and by day's end the next Saturday, we had the engine out on the ground. Pulled the head. Found a tired engine with a considerable ridge at the cylinder top. Flipped it over on a piece of plywood and pulled the oil pan. I removed mains and rod bearing and lifted out the crank. Then out came all the pistons.  Bay day's end Sunday I was staring at a pile of parts and starting to add up the bills. I was in high school and working part time as a dishwasher in a restaurant. If I recall I had about $300 in savings and I got paid again soon. I ordered an engine rebuild kit. I bought a reman exchange crank. Block and head was brought to a local car wash pressure washer where I blasted it as clean as I could. Next trip was to drop the block and head off at a local machine shop.

 

I worked every Friday night after school and all day Sat and Sunday for weeks to pay for the needed parts and machining. Timing chain, carb kit etc. Dad convinced me to pull the torque and have it checked over too. I was tired of school and working, but I wanted my car bad. I had a sweet girlfriend and wanted to take her on dates. With no car, we could not meet very often. She was patient as I worked my butt off to buy everything I needed. She even came and hung out with me sometimes while I was re-assembling the engine. She was an angel.

 

Finally after probably a month we were re-installing the slant 6 engine in my Dart. There was no way we could line it up to the 747 auto transmission bell housing. Finally we determined that the exchange crank I installed was for a different transmission. Drat! More delays. We pulled the torque again and had it machined to fit the crank. All went together well finally. The car started! I was excited. It was idling a little rough but I had no money left for new spark plugs, cap, rotor and wires. My brother took it to his Grade 12 shop class on Monday and hooked up to a scope. Hmm.. Spark looked off. He pulled all the plugs again. I had installed them. Several had zero gap as they had been dropped and kicked about for the past month. I had  little experience and overlooked the plugs. He cleaned and gapped my plugs. Set timing and adjusted carb. He was my hero. The car was running in top shape now. I could not have done the engine rebuild without my brother. I had a ton of respect for him for helping me.

 

Next came the courting again! Dates and ice cream often with my slant 6 Dart. Good memories with my girl. She's still with me today. It was just our 25th wedding anniversary in early January. I was a young dumb 16 year old. I drove the Dart for about 6 months and sold it for something faster. That was a huge mistake. I bought another car that I soon had to rebuild it's engine as well. I repeated the whole process again. I learned the hard way. This time big Bro was in trade school. I was on my own and rebuilt the V6 engine myself. Lots of frustration but what does not kill us makes us stronger. 

 

Below is a pic from 1987.  Here we all are man handling the slant 6 engine. I'm in the blue coveralls. Big bro in the white T-shirt. Dad pulling the hoist. Good memories.

 

 

How does all this relate to the flat head six? Well today I own a '53 Chrysler with a 265 L6 flat head. The story is a little similar. I bought my '53 last May and drove it home. Within a month I had the head off and did a full valve grind and all new valves. I'm a little smarter today with more experience. Today I can afford to order parts as needed. Today my best girl is home with me every night. No stress as I have other vehicles! LOL.  My '53 is not my only car. My old Dart was.

 

I believe the 225 slant 6 was rated at 94 HP. My flat head is rated at 119 HP. I am unsure of the actual torque of each. I would say that my flat head '53 has considerably more torque. It lugs down nicely and pull hills smooth. It was over 30 years ago that I owned the slant 6. The performance details are a little blurry. I do recall street racing my Dart against a 1974 Ford Pinto 4 cylinder, standard 4 speed tranny. It beat me off the line. Today I'd say I prefer the flat 6. I love how it sounds. It idles so quietly. It runs so smooth. It seems easy to maintain. I like it!

Keith, the first crank that you got was for a '66  and earlier 225. I ran into that back in the  early '80's.

[Xlarashun]

Back in the late '60s?early '70s, a trick with Slants was to put in a Truck cam, degree it 4 or 6deg up, get a Marine head, thin copper head gasket and the usual Clifford intake and Header. Super simple and Worked!

A couple of friends back then had what were named 'Deputies' !  225, 3 spd Challengers,  both of them Red. I wish I had them both now!

They hopped up one of them and lined up against the untouched one, which for some reason had been faster out the back door.

Beat him by nearly two and a half cars!

Needless to say, as soon as he saved up for the parts, they did his too!

Memories from the Dusty corners of my mind!

 

[classiccarjack]

Drag racing slant 6 vs slant six is fun!!!  Love it!

[greg g]

The 225 /6 in my fathers 1960 Dart was rated at 145 HP, the 170 @ 101

[55 Fargo]

6 hours ago, greg g said:

The 225 /6 in my fathers 1960 Dart was rated at 145 HP, the 170 @ 101

As Slant 6 Dan states those rating are way too generous the 225 being closer to 105 hp.

Your 230 prolly has a lot more hp and torque at a lower rpm

Edited February 20, 2018 by 55 Fargo Spitfire