Every day economy build

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Larry the Valiant

Larry the Valiant

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Hello all, I am brand new to the mopar world and the slant 6 world with the purchase of a 1964 Plymouth Valiant wagon for my wife. She has been wanting a classic wagon for a cruiser that she can daily. The car came with the factory 225 engine with the aluminum spark plug tubes, the car also came with a 225 engine from a 83 truck by the stamping, it has hydraulic lifters.
since getting the car I've been reading quite a few forum pages, so hopefully I don't make a fool of myself. I'll start with the facts about the engine, the plan, and then my questions
I tore down the 83 block and it seems to be in good condition the cylinders are all 3 thou over spec with no measured signs of coning, as stated before it has hydraulic lifters and the lifter arms have 0 adjustment, I'm thinking this might pose a problem if I decide to up the compression ratio. it has flat top pistons that are .135 down in the hole at TDC. I have not yet removed and torn down the original engine in the car, but the previous owner said it wouldn't turn over.
Since my plan is an economy everyday driver for my wife(she's a very conservative driver) I am planning on adding this EFI kit Deuces Wild 2 (2-bbl) EFI, and locking out the distributor to take advantage of it's timing control, I'm thinking some smarter fuel management will allow me to up the compression ratio as well, I was thinking it would be better to just take the 83 block and have it machine down to reduce the amount of quench area in the hole, rather then remove that area from the head. and then with the cylinders, I'm thinking just a quick re-ring kit on the current pistons.
Here are just a few of the questions I have, I'll try and keep them brief and somewhat related as well.
1. how much dynamic compression can I run with the best combination of cylinder head and block? from what I've read, for weight it seems to be best use the 83 block and the 64 cylinder head? not sure what the best combination would be for usable power/efficiency, based upon head design mainly.
2. for economy would it be better to use hydraulic lifters or solid? I have an MG midget, so I don't mind the lash adjustment every so often, I really just want to target reliability.
3. regardless of whether I go with hydraulic or solid, are there any aftermarket camshafts, or specific years that would help economy most? I know with a small cam adjustment you can add compression, and thus more efficiency.
4. this one might be a stretch, but does anyone have any good experience turboing these for the efficiency? I know it can make loads more power, but if you can keep your foot off the floor theoretically there is a lot to be gained in the efficiency range, and then I wouldn't need to alter the compression ratio that much.

I know that is a lot of questions with very broad and varying answers, I guess I'm just a little overwhelmed by all the options. your answers/build advice, will be much appreciated.

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When saying economy, is the goal to actually save money? Cause if so spending thousands to gain a few mpg's can take a long time just to recoup cost nevermind save money.
 
You do what you want. You seem to already have a plan even before asking for advice. But you did ask. I wouldn't use a hydraulic lifter slant 6 engine for love nor money. The original design was a mechanical lifter engine. The hydraulic lifters started as an afterthought for the 82 model year. There may have been some spotty ones a year or two earlier, but 82 is considered the first full production year. Slant 6 engines do not have pressurized oil to the lifters. None. They are splash fed only. As such, the hydraulic lifters in a slant 6 are oiled DEAD LAST and there's little pressure there. The oil comes through the block, through the rocker shaft stand, into the rocker shaft, through the rocker arms, through the pushrods and FINALLY into the lifters. I remember well when they were new. They had issues with noisy lifters because there is such a huge pressure drop before the lifters even get anything. Lots of people will say "I had one that ran fine for years" and that's fine. Some did. The simple fact is, the slant 6 was never designed as a hydraulic lifter engine and IMO it makes a poor one. Hundreds of millions of solid lifter slant 6 engines were made and served well. There was no need for the change and IMO it was a mistake. I would use the solid lifter engine.
 
If you want to go crazy call Bryce at Gill Welding. Turbo and Port Fuel Injection kits for the 225....

Gill Welding & Fabrication | Performance Automotive | Heiskell | EFI

If you just want a nice running slant.

1) Deck the head and/or block 0.100 total (could be split anyway you want to get 0.100 (there is no quench area in the slant design so it does not matter where you take it off) will get you around 9:1 which make a HUGE difference in everything else you do.
2) Oregon Cams 2016 grind is basically the Dutra Rv10 grind which is a nice torque grind and all the lift required for the poor flow of stock heads
3) Split the front 3 and rear 3 exhaust manifolds, Dutra Duals out of AussieSpeed are one option, then run 2 pipe back behind the transmission crossmember before "Y" ing them back together put the torque peak at cruising RPM (about 3000). The further back you put the Y the lower the torque peak will come in. Doug Dutra put it back by the rear axle and said the torque off idle was noticeable.
4) A bit more carb. I used a dual one barrel Offenhouser but you can find Super 6 two barrel manifolds around as well. No reason (and can actually be a drivability struggle) to go above 400 CFM or so.
5) I increased the valve diameter but that really only helps if you are winding it up past 3000 RPM often, otherwise not needed.

My opinion on EFI:

I put it on my first restoration and will NEVER EVER do that again. The effort and cost did not even come close to any real benefits other than no heat soak starting problems. A well tuned carb will work just as good and will not leave you stranded with no way to fix it other than carrying around a complete second EFI setup and fuel pump with you. Do not fall into the trap of EFI gets better fuel economy.. That is bogus. A well tuned carb will be virtually the same. Cars today are EFI for emissions. Fuel economy comes from increased Volumetric Efficiency, aerodynamics and lowering engine RPM (read gear ratio).

Edit:

Fixed the link to Bryces website.
 
Last edited:
Larry the Valiant said:
Hello all, I am brand new to the mopar world and the slant 6 world with the purchase of a 1964 Plymouth Valiant wagon for my wife. She has been wanting a classic wagon for a cruiser that she can daily. The car came with the factory 225 engine with the aluminum spark plug tubes, the car also came with a 225 engine from a 83 truck by the stamping, it has hydraulic lifters.
since getting the car I've been reading quite a few forum pages, so hopefully I don't make a fool of myself. I'll start with the facts about the engine, the plan, and then my questions
I tore down the 83 block and it seems to be in good condition the cylinders are all 3 thou over spec with no measured signs of coning, as stated before it has hydraulic lifters and the lifter arms have 0 adjustment, I'm thinking this might pose a problem if I decide to up the compression ratio. it has flat top pistons that are .135 down in the hole at TDC. I have not yet removed and torn down the original engine in the car, but the previous owner said it wouldn't turn over.
Since my plan is an economy everyday driver for my wife(she's a very conservative driver) I am planning on adding this EFI kit Deuces Wild 2 (2-bbl) EFI, and locking out the distributor to take advantage of it's timing control, I'm thinking some smarter fuel management will allow me to up the compression ratio as well, I was thinking it would be better to just take the 83 block and have it machine down to reduce the amount of quench area in the hole, rather then remove that area from the head. and then with the cylinders, I'm thinking just a quick re-ring kit on the current pistons.
Here are just a few of the questions I have, I'll try and keep them brief and somewhat related as well.
1. how much dynamic compression can I run with the best combination of cylinder head and block? from what I've read, for weight it seems to be best use the 83 block and the 64 cylinder head? not sure what the best combination would be for usable power/efficiency, based upon head design mainly.
2. for economy would it be better to use hydraulic lifters or solid? I have an MG midget, so I don't mind the lash adjustment every so often, I really just want to target reliability.
3. regardless of whether I go with hydraulic or solid, are there any aftermarket camshafts, or specific years that would help economy most? I know with a small cam adjustment you can add compression, and thus more efficiency.
4. this one might be a stretch, but does anyone have any good experience turboing these for the efficiency? I know it can make loads more power, but if you can keep your foot off the floor theoretically there is a lot to be gained in the efficiency range, and then I wouldn't need to alter the compression ratio that much.

I know that is a lot of questions with very broad and varying answers, I guess I'm just a little overwhelmed by all the options. your answers/build advice, will be much appreciated.

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Nice wagon! You beat me to that one. Looks like a fun project. Did it have the grill or was it missing?
 
sweet long roof! i saw that thing posted up and was mighty tempted!

jim and rusty's advice is spot on. deck it to get some compression, get a mild cam in there, upgrade the exhaust and see if you can hunt down a 2bbl set up.
 
junkyardhero said:
sweet long roof! i saw that thing posted up and was mighty tempted!

jim and rusty's advice is spot on. deck it to get some compression, get a mild cam in there, upgrade the exhaust and see if you can hunt down a 2bbl set up.
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Also don't expect gut wrenching speed.... it is only 225 cubes! What the mods I outlined do it make the slant run as well as a modern 4 cylinder. The dollars per Ft-Lb of increased torque will never be as dramatic as a V8 but to be honest I will walk past my hot rodded 318 and 360 in other cars to drive the Dart with the slant. It is just a hoot to drive....



Jim
 
Jim Kueneman said:
Also don't expect gut wrenching speed.... it is only 225 cubes! What the mods I outlined do it make the slant run as well as a modern 4 cylinder. The dollars per Ft-Lb of increased torque will never be as dramatic as a V8 but to be honest I will walk past my hot rodded 318 and 360 in other cars to drive the Dart with the slant. It is just a hoot to drive....



Jim
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jim, your rides exemplify: looking good > going fast

such a great car and amazing attention to detail.
 
Oh and one more thing. The 318 is known for getting better mileage than the slant 6, so there's THAT. If you do a slant 6, you do it for the love of the engine. It likely ain't ever gonna be a miser on gas. The hot slant 6 in Vixen, my 64 Valiant knocks on the door of 20 MPG, but that's about it. I'm plenty happy with that.
 
RustyRatRod said:
Oh and one more thing. The 318 is known for getting better mileage than the slant 6, so there's THAT. If you do a slant 6, you do it for the love of the engine. It likely ain't ever gonna be a miser on gas. The hot slant 6 in Vixen, my 64 Valiant knocks on the door of 20 MPG, but that's about it. I'm plenty happy with that.
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Not in my world.

EFI 318, 2.73 gear Coronet = 13MPG
Edelbrock 650 CFM 2.73 gear Duster CFM 318 = 13MPG
Edelbrock 500 CFM Valiant 3.21 gear 13MPG
Hotrodded 225 Dart 3.23 gear as outlined above 19 MPG
 
Jim Kueneman said:
Not in my world.

EFI 318, 2.73 gear Coronet = 13MPG
Edelbrock 650 CFM 2.73 gear Duster CFM 318 = 13MPG
Edelbrock 500 CFM Valiant 3.21 gear 13MPG
Hotrodded 225 Dart 3.23 gear as outlined above 19 MPG
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You got something WRONG with the Duster and Valiant.
 
RustyRatRod said:
You got something WRONG with the Duster and Valiant.
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Same math was used for all but the Coronet (did not know better then) they run great but they get exactly what Mopar said they will get in their documentation. The Duster (318) has Toth ported heads and Edelbrock 268 cam and the Valiant (360) had Toth built Edelbrock heads and Oregon cam 819 cam.
 
Jim Kueneman said:
Same math was used for all but the Coronet (did not know better then) they run great but they get exactly what Mopar said they will get in their documentation. The Duster (318) has Toth ported heads and Edelbrock 268 cam and the Valiant (360) had Toth built Edelbrock heads and Oregon cam 819 cam.
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I had a 71 Dart street car. 360, 904, mild converter and 3.23 gears. It regularly saw 18-21. You got somethin wrong somewhere. While I say that, we ARE in completely different locations and the quality of gas might be different.
 
RustyRatRod said:
I had a 71 Dart street car. 360, 904, mild converter and 3.23 gears. It regularly saw 18-21. You got somethin wrong somewhere. While I say that, we ARE in completely different locations and the quality of gas might be different.
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I drop and climb 3000 ft and spend 30 minutes at 75MPH+ on the freeway to get anywhere too so those are likely factors into it as well.
 
Jim Kueneman said:
I drop and climb 3000 ft and spend 30 minutes at 75MPH+ on the freeway to get anywhere too so those are likely factors into it as well.
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my 41 build ...76 318 out of a aspen..904...600 carb headers light cam..@ 3500 ft 18mpg......@ sea level 22...of course adj fuel and timing stock converter......but that little 318 was down right easy on fuel...my foot was never in it...full tank about 2600 lbs i hope this 64 gets at least 20 mpg....rrr you hurt my feelings saying she will not............i hope your wrong.....
 
How about 1.89 LS valves, only about .090 longer, could trim them a lil and play with the seat depth.
 
My experience with TBI conversations is that the fueling won't help with economy compared to a properly tuned carburetor. There can be gains from the programmable timing curve if it's tuned right - but you can use programmable timing with a carb too. I also would not recommend TBI plus a turbo - they have to run richer to compensate for lousy fuel distribution under boost compared to multiport. But the cost for an EFI system and proper tuning will be so high that the fuel savings won't pay for it unless you are putting tens of thousands of miles on the Valiant every year.

The idea of a turbo for fuel economy is also more about using a small turbo motor over a large naturally aspirated one. Or a mileage comparison between a turbo motor versus a wild naturally aspirated build making equal horsepower. They're not a mileage enhancement on their own.

If I were doing a mileage build to save money, I would just do a two barrel carb, good exhaust, mill the head for a bit more compression, and make sure everything is working and tuned properly.
 
MadScientistMat said:
My experience with TBI conversations is that the fueling won't help with economy compared to a properly tuned carburetor. There can be gains from the programmable timing curve if it's tuned right - but you can use programmable timing with a carb too. I also would not recommend TBI plus a turbo - they have to run richer to compensate for lousy fuel distribution under boost compared to multiport. But the cost for an EFI system and proper tuning will be so high that the fuel savings won't pay for it unless you are putting tens of thousands of miles on the Valiant every year.

The idea of a turbo for fuel economy is also more about using a small turbo motor over a large naturally aspirated one. Or a mileage comparison between a turbo motor versus a wild naturally aspirated build making equal horsepower. They're not a mileage enhancement on their own.

If I were doing a mileage build to save money, I would just do a two barrel carb, good exhaust, mill the head for a bit more compression, and make sure everything is working and tuned properly.
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Right, the other factor for fuel economy is vacuum. If you have to push into the throttle to keep moving (like a normal worn out stock 60 year old slant) it drops the vacuum. That is why the Super 6 often gets better mileage with the 2 barrel and bigger exhaust.

I have the equation for fuel usage in an engine somewhere and the main factors are what I said earlier.

- Cubic inches (smaller the better)
- RPM (lower the better)
- Volumetric Efficiency (higher the better but if you look at the math it is not a strong effect for what you can reasonably achieve)
- Friction (aerodynamics/weight/rolling resistance)
- Vacuum (higher the better)

The vacuum is what hurts if you drop the RPM and cubes too low as you have to put your foot in it more to maintain speed (fighting the friction factor). It is all an optimization game.
 
Ok... You want to replace the engine because the PO says "it won't turn over"... Is it seized?
If it's not it WILL "turn over".... When you hit the key will the starter spin the engine? That's ALL that "turning over" entails. I wouldn't take the POs assessment. See what you can do with the original one first. "Turning over" says nothing for ignition or whether it's getting fuel or tries to fire or not. Sorry that one drives me crazy so often people associate "turning over" with "won't run" and they ate often 2 very different things
 

Thanks for the replies everyone. Sounds like I'll go with the solid lifters, and a mild cam. nothing to crazy to start off, and I can modify later as I see fit. from what I've read I should use the later block to save some weight, will I have any issues using solid lifters in that engine? and also does it matter at all which head I use?
 
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