HAVING SIX

[dulcich]

So, I've had this slant six 1968 Dart for years and it has served me well. I bought it years ago, and as recently as a couple of years ago, I came down to the Dart as my only running car. Considering I never did anything to it after the initial get-it-running thrash when I got it, I consider that pretty good. So, yesterday, I pulled the motor. Reason? The last time I used it the exhaust manifold cracked in three pieces. It had been cracked since day one, but after a trip last July to Shaver Lake, it was all broken.

Bought a Clifford header, but of course ended up with broken studs in the heads. I decided since it leaks oil everywhere and is caked in grease, I might as well pull it and go through the engine.

What I Found:
Engine is 0.040-over, with 0.0007-0.001 taper. Wow, this thing is brand new.
Pistons are 0.175 in the hole.
55cc heads.

What I Want To Do:
Make more horsepower. It was pretty weak.

What I Don't Want To Do:
Swap to something else, even though I have plenty of other engines to choose from.

Plan
Keep it simple to avoid getting bogged down.
Disassemble, deck 0.060
Hand hone and re-ring
Bearings
Gaskets
Mill heads 0.060 for 10:1 compression with the same 0.040 pistons.
Howard's Cam, 220/220 0.475 on 110
Clifford header that started all this.
Port head.
Install old 1.74 Chrysler big block exhaust valve as intake valve (1.62 stock)
Install old 1.6 Chrysler big block valve cut down to 1.5 as exh. valve (1.36 stock)
Cut runners off stock intake manifold and fab new four barrel plenum. Arc weld.
Thermoquad

I have 10 pages of drawings on the intake manifold and it looks like it will be easy to make and really badass. Composite of the stock cast iron runners, ported, and 1/8 mild steel,

[Deaf Bob]

Probably not telling you anything new, but are you using the 2 barrel intake that came on the "Super 225"?
I'm told it is a little bigger..

[tardis454]

Fugg Roadkill, need Dulcich's Garage channel. (You can call it Barn Yard Cars)

**Thermoquad? ain't them those composite body carbs that warp and run like crap... like the one my buddy had on his 73 Imperial's 440?

[dulcich]

Fugg Roadkill, need Dulcich's Garage channel. (You can call it Barn Yard Cars)

**Thermoquad? ain't them those composite body carbs that warp and run like crap... like the one my buddy had on his 73 Imperial's 440?

Yup, those are the carbs. Love those things! You cannot find mors CFM per $.

[dulcich]

Probably not telling you anything new, but are you using the 2 barrel intake that came on the "Super 225"?
I'm told it is a little bigger..

I have one of those and was goinv to use that with a BBD until I realized just how lame a two barrel is. Still, did not want to cut it up, so I will use the runners from a stock one barrel manifold. I think those will port as big as the intake ports anyway.

[tardis454]

Yup, those are the carbs. Love those things! You cannot find mors CFM per $.

So yeah, Dulcich's Barn Yard Cars? Bangshifters would watch it.

[Deaf Bob]

I have one of those and was goinv to use that with a BBD until I realized just how lame a two barrel is. Still, did not want to cut it up, so I will use the runners from a stock one barrel manifold. I think those will port as big as the intake ports anyway.

2 barrel 500 cfm Holley!
Kid's 350 shreiks with one jetted for it..
Have 2 main ones for the same motor, one for race gas, the other for E-85..
Even have one jetted for a mild 327

[DanStokes]

First of all, I'm shocked that someone put of a pic of having Six on BS - though it WOULD be you if anyone.

Second - isn't the TQ going to be a bit much for the little /6? Withe my Chevy 250 I ended up with a Holley 425 (IIRC - it was Holley's recommendation) and I had to jet it WAY down - enough that I had to order jets because they needed to be smaller than what comes in the jet packs that the tuner had. It ran pretty well after that on the Holley.

Just a question.

Dan

[Beagle]

The fabled Dart. Man that thing looks straight!

Did the aliens talk to you in your sleep and tell you that everything should be focused on torque production at a higher RPM this week Dulcich? Not that there's anything wrong with that, and it sounds like it will be a neat mill. I had a couple of immediate reactions aside from the immediate WTF?!! .175 Chasm and "gaskets and stuff a turbo on it." (that would take care of the exhaust issue)

Swap rears so you can get some gear under there? I'm thinking 4.10-4.30 and a deep OD
or
Dakota six speed and as close to a 3.something rear as you can get. They looked to have some sexy ratios but only a .79 OD. A 12:1 first gear should take care of whatever missing low-end torque the engine has at stoplights? I didn't notice and don't remember if this has a A883 in it... but the extra spread from two more gears might be worth the hassle if it would fit.

The intake sounds cool, but again, made me wonder about short or tunable length individual runners. I'm one of those guys who finds the sound of a six at speed intoxicating. By all means, get to it man!

[dulcich]

Dan, the Thermoquad might be too big, but it is easy to swap. Used to run a 215 Olds in a Jeep, and that was great with a Holley 600. AFB 625 was also great on that tiny Oldsmobile engine, but they are no good off.road. I have a nice 1 3/8 primary Thermoquad that might be good. Chrysler put them on 150 hp 318s.with 2.2 rear gears.

Beags, turbo is out, since I already bought headers. Runners on intake will end up the lenght of the original center two, about 5 or 6 inch. Keeping the 904 Torqueflite and 2.7 freeway gears. If this thing makes 250 hp I would like it. I used it mostly for jamming down to LA, or road trips, adventures.

[Russell]

Nothing wrong with a sixer. Love to see others build them but I rather have a v8. Do you think it will have more or less torque than before under 2k rpms?

[>>>>head]

.................... need Dulcich's Garage channel. (You can call it Barn Yard Cars) ....................

I'm in !!

[TheSilverBuick]

With a 220 duration cam, will it bleed off enough compression to not be a rattle trap with 10:1, especially with the pistons still being a mile down in the hole? And being a six cylinder, it's always going to be loaded up. Any thoughts on some fancy angle milling of the head surface and intake/exhaust surface for better air flow?

I look forward to seeing how this goes

[dulcich]

Nothing wrong with a sixer. Love to see others build them but I rather have a v8. Do you think it will have more or less torque than before under 2k rpms?

I think it will be an animal down low. 10:1 good intake and exhaust, small solid cam. Really, this thing the way it was couldn't pull the hat off your head. It was really low powered, but would cruise effortlessly at 80+ with the tall gears. It only got about 17, maybe 18 mpg tops on the highway.

So my 4 barrel intake design is based on the idea of making something good from pure garbage at a cost of next to nothing.

I drew up plans a few months ago for a totally great fabbed sheetmetal EFI intake. That would be another option. Downsides: It would be much more time consuming to make; It means my bulletproof and unstoppable Dart will have to rely on an electronic box to run.

[squirrel]

wouldn't it be easier to swap in some 3.23 gears?

The Thermoquad is a demand secondary carb, with tiny primaries, like a Qjet, right? Should be fine.