225 long rod stroker, HELP

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65PlumCrzy

65PlumCrzy

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I've been back and forth with the idea of milling a 225 and battle the pushrod lengths, squish clearance and other issues that come with milling so much off a motor. OR go with something I know even less about and that's doing a long rod stroker, 198 rods on a 225 crank in a 225 block with 2.2l pistons. I'm building my wife a 1965 Dart GT. The plan is to have a show and go tribute car to Cervical Cancer in honor of my wife. This will be a full interior, full body build, something she can scoot around in, turn heads, and possibly upset some Mudstains and Slomaros in the process. I already have an Offy 4bbl intake, Hooker Headers, and a 500 CFM Eddy carb. Which is more practical? Which would be more reliable, streetable setup? Transmission will stay the 904 with a shift kit and rear end will either be a 7.25 with 4.10 gears or upgraded to a 8.25 with a 3.55 gear. I've been getting input from a handful of guys out there info is limited. SlantSix.org is where I read about the long rod stroker. This is her baby and she's getting dirty on it.

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And no, I haven't decided on what cam. She wants it to lope so I see a stall converter in my future plans. That's another headache in itself cause I'm not sure if the /6 convert that year is available in a stall. Just another piece of the puzzle.
 
All the scientists are going to jump in and tell me I'm wrong..but putting a longer rod in a 225 is the absolute worst thing you can do to the damn thing.
It needs all the mechanical leverage it can get, and taking that away via a longer connecting rod will crush the tiny bit of bottom end torque it has to begin with.
If you plan on spinning it to 9 grand, go for it..otherwise leave well enough alone.
BTW...don't take my word for it. . This is basic engine building 101. Google is your friend. Search "Rod Length Effect on Torque" and do some reading
 
I won't even get into the discussion of benefits/drawbacks of long rods. For a street driver it is not cost effective. Just the rod/piston (K-1/Molner, Wiesco) package will cost about $1100. Stock 198 rods (if you can find a set) should get ARP bolts ($55), and be reconditioned ($150). Pistons would be minimum $160 plus rings. There is nothing wrong with stock rods (reconditioned) and stock type pistons, on a N/A street car.

High stall converters are available with the small pilot, small spline or the large pilot, large spline. It is the "hybrid" (small pilot, large spline) that are getting harder (expensive) to obtain.

I am a fan of the 7 1/4 rear, but parts are getting harder to find, and if not a sure grip prone to breakage, if beating on it. If you are going to change the rear I would go for the 8 1/4, Ford 8.8, or 8 inch Ford, which is almost a bolt in (early v-8 mustang, comet, Falcon, Granada).
 
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Ok, I'll be that guy...are you married to the slantie?
It's a great conversation started but if you want to embarrass mudztanks with it, the economic option would be a 360

Or how do you feel about boosting the slantie?
 
First, you need to understand that putting a longer rod in any engine doesn't make it a stroker. It takes a longer stroke on the crankshaft itself.

Beyond that, the only advantage I see to the longer rods is getting compression up with the 2.2 non turbo pistons. That can be done easily with the stock rods by using custom pistons.
 
I'm with Tony, and this is a street car. Build for torque and gear accordingly and the miss will stay happy.

Got money to burn? Want street cred? Boost it.
 
I appreciate it guys. I'm following a tech setup I found on SlantSix.org forum. To answer some question and comments. No a V8 isn't really an option at this time. I have thought about a 5.9 Magnum swap with overdrive that I have sitting in a Dodge van. I understand the longer rod doesn't make a stroker, the advantage to the longer rod, from my understanding, is to close the combustion chamber up to increase compression. Long rod + relocated piston pin on the 2.2l piston = higher compression. Simple math guys, I know there is more involved. Its something I read about and wanted to get some input. I'm interested in the Hughes Racing Whiplash cam which is suppose to increase cylinder pressure and doesn't require all the machining of the block and makes descent power, but its a less traveled road and I can't get any REAL feed back from anyone that has used it. And for the others, FI sounds great, might as well set aside 5-8k on engine build including the FI kits. And she doesn't want a blow dryer on the motor. lol. This post is for what you guys are doing. Thank you for the input and please correct me where I'm wrong on all this,
 
Wow...I think I need to do some reading, because all this time I've read that longer rods are better, but maybe that's for V8 engines? I even read about the 198 rod in a 225 trick too.

In the past I've read that longer rods flattens out the torque curve. Back in my Ford days (in the early 90's), the theory was proven with long rods in 302's. If cost wasn't an issue, it was the the way to go. The goal was to improve the rod ratio.

I did a preliminary search on the topic and found the following article, but I know I should keep reading.

https://www.hemmings.com/magazine/hcc/2009/06/The-Mechanical-Advantage/1827793.html

Maybe the whole rod ratio debate is almost asking like which oil is better. LOL

By the way, a fuel injected Slant 6 would be cool!! Sure, not cost effective but cool!

Maybe give these guys a call and see what they say:

Jack Clifford' Performance Products inc. - Headers Intakes Cams For Inline Six Cylinder Engines, Inl

951-471-1161

These guys may have some input too:

Aussie speed performance manifolds alloy valve covers roller rocker spacers air filters for Holden Ford Valiant Chevrlot V8 V6 and inline 6 cylinder engines Aussiespeed performance shop
 
JoesEdge said:
Wow...I think I need to do some reading, because all this time I've read that longer rods are better, but maybe that's for V8 engines? I even read about the 198 rod in a 225 trick too.

In the past I've read that longer rods flattens out the torque curve. Back in my Ford days (in the early 90's), the theory was proven with long rods in 302's. If cost wasn't an issue, it was the the way to go. The goal was to improve the rod ratio.

I did a preliminary search on the topic and found the following article, but I know I should keep reading.

https://www.hemmings.com/magazine/hcc/2009/06/The-Mechanical-Advantage/1827793.html

Maybe the whole rod ratio debate is almost asking like which oil is better. LOL

By the way, a fuel injected Slant 6 would be cool!! Sure, not cost effective but cool!

Maybe give these guys a call and see what they say:

Jack Clifford' Performance Products inc. - Headers Intakes Cams For Inline Six Cylinder Engines, Inl

951-471-1161

These guys may have some input too:

Aussie speed performance manifolds alloy valve covers roller rocker spacers air filters for Holden Ford Valiant Chevrlot V8 V6 and inline 6 cylinder engines Aussiespeed performance shop
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At the risk of oversimplifying things...some engines are born with shorter rods than others, and can benefit from a longer one.
THE 225 IS NOT ONE OF THEM...period, end of debate.
The engine is insanely oversquare with not nearly enough piston surface area to adequately work the crank without massive amounts of leverage. The longer rod decreases this leverage, reducing angularity in the early stages of the power stroke...exactly where it needs it the most.
When someone finally offers a cross flow, overhead cam cylinder head for a the Slant that is capable of supporting 10,000 RPM, there will be some merit to a longer than stock rod in the 225. Until then, it is pure idiocy perpetuated by people who have too many fingers on their hands
 
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whitepunkonnitro said:
At the risk of oversimplifying things...some engines are born with shorter rods than others, and can benefit from a longer one.
THE 225 IS NOT ONE OF THEM...period, end of debate.

The engine is insanely oversquare with not nearly enough piston surface area to adequately work the crank without massive amounts of leverage. The longer rod decreases this leverage, reducing angularity in the early stages of the power stroke...exactly where it needs it the most.

When someone finally offers a cross flow, overhead cam cylinder head for a the Slant that is capable of supporting 10,000 RPM, there will be some merit to a longer than stock rod in the 225. Until then, it is pure idiocy perpetrated by people who have too many fingers on their hands
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Ah...now THAT does make sense. Sounds like a good enough reason for me.

But I think you meant under-square where the bore diameter is much smaller than the stroke length, right?
 
65PlumCrzy said:
I'm interested in the Hughes Racing Whiplash cam which is suppose to increase cylinder pressure and doesn't require all the machining of the block and makes descent power, but its a less traveled road and I can't get any REAL feed back from anyone that has used it.
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The Whiplash cam just moves the intake and exhaust lobes closer together (smaller LSA) and thus closes the intake a bit earlier and helps cylinder pressures... a bit. But the cost is a big overlap time and that hurts low RPM performance with a lot of intake charge going down the exhaust and a lot of intake reversion that dilutes the charge.. bottom line is that the low RPM performance will be worse that what you can achieve. It falls into the category of a poor substitute for real compression ratio. All in all, not anywhere near as effective as the standard methods of raising compression in milling heads and/or block.

IMHO, the long rod idea offers a very limited margin of improvement in specific circumstances.... as post #4 puts it, it is not very cost effective for what you sound like you want.
 
nm9stheham said:
The Whiplash cam just moves the intake and exhaust lobes closer together (smaller LSA) and thus closes the intake a bit earlier and helps cylinder pressures... a bit. But the cost is a big overlap time and that hurts low RPM performance with a lot of intake charge going down the exhaust and a lot of intake reversion that dilutes the charge.. bottom line is that the low RPM performance will be worse that what you can achieve. It falls into the category of a poor substitute for real compression ratio. All in all, not anywhere near as effective as the standard methods of raising compression in milling heads and/or block.

IMHO, the long rod idea offers a very limited margin of improvement in specific circumstances.... as post #4 puts it, it is not very cost effective for what you sound like you want.
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I just got a strong confirmation on a 198 motor for $150.00 and less than a 2hr drive. With the cost of the rods just diminished greatly is the longer rod still a crap idea. Doug Dutra did the article about the build but doesn't share any performance info about it. With milling the block and head so much, what issues would I run into when it comes to push rods and valve clearance?
 
RustyRatRod said:
the only advantage I see to the longer rods is getting compression up with the 2.2 non turbo pistons.
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Nope, that's not it. The point of using the 2.2 pistons is to move the pin bore up, allowing a longer rod while keeping reasonable compression. And the reason you'd want to do that is to get the advantages of a better rod/stroke ratio: longer piston dwell time at TDC (= more cylinder pressure develops before the piston starts to move down = more zoom) and less side-loading of the pistons against the cylinder walls (=lower frictional loss). The rings those pistons take are also thinner, which also contributes to lower engine friction.
 
slantsixdan said:
Nope, that's not it. The point of using the 2.2 pistons is to move the pin bore up, allowing a longer rod while keeping reasonable compression. And the reason you'd want to do that is to get the advantages of a better rod/stroke ratio: longer piston dwell time at TDC (= more cylinder pressure develops before the piston starts to move down = more zoom) and less side-loading of the pistons against the cylinder walls (=lower frictional loss). The rings those pistons take are also thinner, which also contributes to lower engine friction.
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I was leaving out the long VS short rod argument,as I think that would cloud up the OP's thread. I think that's best for another thread.

So yes, for MY point, that is "IT".
 
RustyRatRod said:
I was leaving out the long VS short rod argument,as I think that would cloud up the OP's thread. I think that's best for another thread.
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Uhhh…another thread aside from this one right here where the OP asked specifically about a long-rod 225 build? I donno, this seems like the right thread to be discussing long-rod 225 builds. YMMV. ¯\_(ツ)_/¯
 
slantsixdan said:
Uhhh…another thread aside from this one right here where the OP asked specifically about a long-rod 225 build? I donno, this seems like the right thread to be discussing long-rod 225 builds. YMMV. ¯\_(ツ)_/¯
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Go ahead. I am not getting in it. I have my opinions but I am stayin outta that part. lol
 
RustyRatRod said:
Go ahead. I am not getting in it. I have my opinions but I am stayin outta that part. lol
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I would like for you to stay in the thread. I just located a 198 assembly for $150. Why are you against the idea of a longer rod? You aren't gonna hurt my feelings.
 
65PlumCrzy said:
I would like for you to stay in the thread. I just located a 198 assembly for $150. Why are you against the idea of a longer rod? You aren't gonna hurt my feelings.
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I'm not against it. I like it where I think it can be of use. It all boils down to what engine you are using and what you are doing with it. A longer rod is not always a benefit. Piston speed slows with a long rod. A street engine......or small cube engine for race purposes needs a high piston speed. That's where short rods will benefit. As with everything, there is no right or wrong answer, because it all depends on what you have and what your intended use is.

That said, I would pay somebody good money to be able to tell the difference in the seat of the pants between how a long rod motor and a short rod motor runs, all things equal.

Ain't happenin.
 
RustyRatRod said:
I'm not against it. I like it where I think it can be of use. It all boils down to what engine you are using and what you are doing with it. A longer rod is not always a benefit. Piston speed slows with a long rod. A street engine......or small cube engine for race purposes needs a high piston speed. That's where short rods will benefit. As with everything, there is no right or wrong answer, because it all depends on what you have and what your intended use is.

That said, I would pay somebody good money to be able to tell the difference in the seat of the pants between how a long rod motor and a short rod motor runs, all things equal.

Ain't happenin.
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I follow you on short/long when it comes to turning up a motor, but wouldn't that be the stroke not rod length. I'm not changing the crank stroke, being the 225 crank in a 225 block. Going from a 6.7" to a 7" rod length.
 
If that 198 has six rods that are at least rebuildable, $150 is a screamin deal; go get it!

The shrill, strident "Don't do it!!!!!!" arguments about a long-rod 225 build don't really happen on slantsix.org, but on here where Slant-6 experts are fewer and Slant-6 non-experts are more, it flares up from time to time. It's always the same: those who know what they're talking about in regards to this particular kind of build of this particular kind of engine, versus those against the idea even though they don't, but refuse to let that stop them handing out advice.

If you want to read useful conversations on the topic, start here.
 
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slantsixdan said:
If that 198 has six rods that are at least rebuildable, $150 is a screamin deal; go get it!

The shrill, strident "Don't do it!!!!!!" arguments about a long-rod 225 build don't really happen on slantsix.org, but on here where Slant-6 experts are fewer and Slant-6 non-experts are more, it flares up from time to time. It's always the same: those who know what they're talking about in regards to this particular kind of build of this particular kind of engine, versus those against the idea even though they don't, but refuse to let that stop them handing out advice.

If you want to read useful conversations on the topic, start here.
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Awesome reads. Gives me a real good direction to go in.
 
slantsixdan said:
If that 198 has six rods that are at least rebuildable, $150 is a screamin deal; go get it!

The shrill, strident "Don't do it!!!!!!" arguments about a long-rod 225 build don't really happen on slantsix.org, but on here where Slant-6 experts are fewer and Slant-6 non-experts are more, it flares up from time to time. It's always the same: those who know what they're talking about in regards to this particular kind of build of this particular kind of engine, versus those against the idea even though they don't, but refuse to let that stop them handing out advice.

If you want to read useful conversations on the topic, start here.
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Point out anything I said was wrong. I will debate you all you want. Your holier than thou **** gets old.

I've disagreed with nothing you've said. All I did was lay out a few facts. I haven't really argued one way or the other.......and I will not.
 
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