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| I need a recipe... https://slantsix.org/forum/viewtopic.php?t=58451 |
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| Author: | vntned [ Tue Sep 29, 2015 6:12 am ] |
| Post subject: | I need a recipe... |
Car in question is a '64 Dart 170 2dr. Factory it was a complete stripper with the only options being a heater and front lap belts. It came with the 170ci slant, 3spd on the column and an open 7.25" with 3.23 gears. When I bought it a few years back the stock motor, at nearly 200k miles smoked like a train and drank oil. I replaced it with a lower mile '66 170ci. The only changes from stock were a Pertronix ignition and a muffler. I drove it that way for about a year or so and the brake system failed. So I pulled it off the road, replaced/upgraded everything in the suspension and brakes. Disc brake conversion, bigger Tbars, new shocks, all new suspension bushings, front end rebuild kit, new leaf springs, Hellwig swaybars front and rear, and I replaced the rear end with an 8.25" Abody with 3.55s and a SureGrip. I also pulled the 3spd in favor of an A/F body 4spd OD. The problem now, is that the lack of acceleration is getting to me. And while I've dabbled in the idea of anything from boosting the 170, to a stroker 210, and even a small block swap. Ultimately though, I don't want the associated tuning problems with turbos, the added expense of a stroker build or the poor economy of a v8. So I've decided to go with a 225 build. I'm going later today to pick up a '66 Dart 270 sedan. It's got a 225ci with a 3 on the tree and is completely stock. I'm gonna pull the motor for a rebuild. What I need is a recipe on a good street motor that'll be spunky and still deliver decent economy. What do you guys suggest?! |
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| Author: | NEVjr [ Tue Sep 29, 2015 4:12 pm ] |
| Post subject: | |
perhaps lower rear gears and a 5 speed with some good overdrive is the solution? |
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| Author: | Reed [ Tue Sep 29, 2015 4:34 pm ] |
| Post subject: | |
3.55 is a pretty aggressive rear axle gear for the street. What transmission gear are you accelerating in? Have you verified your base timing and the operation of your vacuum and mechanical advance mechanisms in the distributor? Even a 170 should be able to accelerate pretty good with 3.55 gears if everything is in good working order. |
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| Author: | Rick Covalt [ Tue Sep 29, 2015 5:08 pm ] |
| Post subject: | |
He has an O/D transmission. So whatever you build you will be much happier with at least 3.91 or 4.10 rear gear. My sons Dart has ran on the street for 10 years with 4.30 gears and O/D. It got over 20 MPG and ran 14's in full street trim. There are plenty of builds on here just do a little searching and post back with your specific questions. Rick PS. There was a set of 4.10 gears for sale on here for months. Maybe they are still available. |
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| Author: | Reed [ Tue Sep 29, 2015 6:41 pm ] |
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The fact it is an od trans won't affect acceleration in gears 1-3. If acceleration is poor in gears 1 or 2, there is a problem somewhere. My first thought was timing advance because the distributor has been worked on and timing advance is a common source of lack of power during acceleration. |
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| Author: | ESP47 [ Tue Sep 29, 2015 8:27 pm ] |
| Post subject: | |
I limped a parts car home with a 225 1bbl and 3.23 sure grip in the back. The car blew up as I got to my street but that thing accelerated twice as fast as my rebuilt 225 2bbl with 2.76 gears. If you can't accelerate with 3.55's then you have some sort of problem that shouldn't require throwing a bunch more money at it unless that's just what you want to do. |
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| Author: | vntned [ Wed Sep 30, 2015 4:07 am ] |
| Post subject: | |
Apparently something got lost in translation. The car accelerates as good as any stock 170ci ever has. I just want more power. Call me crazy, but i want it to be faster than a stock 170... |
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| Author: | Charrlie_S [ Wed Sep 30, 2015 5:34 am ] |
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This is my opinion. Increase the compression to 9.0-9.5, (depending on cam). Install a mild cam, and a 2 bbl carb. Free flowing exhaust. Recurve distributor(electronic, if not already) to match compression and cam. |
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| Author: | Dart270 [ Wed Sep 30, 2015 6:11 am ] |
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Hi vntned, You might take a look through the engine build thread and then ask about buildups listed in there. http://www.slantsix.org/forum/viewtopic.php?t=23314 I need to post a couple of engine builds/results there, but there a bunch of good combos already listed. My "200HP..." post combo from 2014 was built/installed/tested in a 64 Valiant last year. Happy to discuss further, Lou |
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| Author: | Sam Powell [ Thu Oct 01, 2015 4:51 pm ] |
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I'm really chewing on this right now. I am getting antsy to build a hyraulic engine soon, even though there is no urgent reason to do so. The current engine works well enough, but is too much of a mismatch of cam, piston and head treatments to be a great combo. It drives nice, and has decent road feel power-wise, but does not yield the economy the stock engine with a supersix provided. It seems the hard part is setting the goals. There has been much knowledge accrued and made available here. Though disagreements do exist on some issues, those are rare. The challenge then, as said, is deciding what compromises one wants to make. The fastest cars have poor drivabilty (idle fast, idle poor, and max hp and torque rise in the rpm band. ). As you make decisions to improve drivability, over-all power goes down, (both max, and where it falls in the rpm curve) economy tends to go up, idle can be made lower, and is smoother. Once you can decide for sure what your goals are, there are those here who can help you pick a cam, compression ratio, and final drive ratio. One issue I am a little unclear on is if a ported head, and larger valves hurt torque, (that is raise the max torque in the rpm range?)? It seems as if mating the cam, compression ratio, porting, valve size, and final drive ratio must be matched to each other and the use the vehicle will be used for. You must also decide what gas tpye you intend to run. Sam Sam |
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| Author: | Dart270 [ Fri Oct 02, 2015 3:54 am ] |
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I believe you can go a lot further with valves and head porting on our engines w/o hurting torque because our heads are inherently fairly low flow for the cylinder size (in stock form). I would not worry about that. Cam does not have to be small either, if you run enough compression. My 64 pulls pretty hard at 2000 RPM these days, a lot harder than a stocker at that RPM. Tuning and combo account for a LOT. There are a lot of half truths out there that can be overcome. Lou |
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| Author: | Sam Powell [ Fri Oct 02, 2015 6:02 am ] |
| Post subject: | |
Thanks Lou. That is very helpful. It was an eye opener for me that during last Summers trip to Blacksburg, I got 23 Mpg cruising at 70 mph and 2400 rpm. Even though the noise was annoying at that rpm, it was more efficient that I expected. That was with no OD, and IIRC, the old .273 rear. There is no way to know what the current cam is, since I lost the card along the way somewhere, but am currently thinkin in terms of bigger cam, and cruising at 70 at somewhere around 2200-2400. I must calculate what rear gets me there with .8 overdrive. What rpm were you spinning with the 64 on your cross country trip. Also, to consider is stock lock up torque converter. Goal is smooth idle at 800 Rpm. I am hoping these comments are giving some focus to VNTNED's concerns. I am not trying to hi jack his thread. Sam |
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