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Please help with this decision...
https://slantsix.org/forum/viewtopic.php?t=35250		 Page 2 of 3
Author:  terrylittlejohn [ Sun May 10, 2009 6:05 am ]
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9/1 is a good compression and no more than 32degs, the 270 cam should work good, i used 276 mopar and it pulled strong on the highway at 3000rpms but was soft under 2000rpm`s but it wasn`t a RDP cam, so i think doug`s erson cam will be the better.
Author:  MenkeMoose [ Sun May 10, 2009 9:05 pm ]
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Lou, my engine has spun a bearing (actually why I'm rebuilding), so i was expecting to have to pay for crank work anyway. Getting the crank stroked to 4.4" is certainly in the realm of possibility. I think I read the the 2.2 pistons are no longer available. What pistons would you use for this? Could I use my stock type (.060 over) pistons?

I've read the stroking article, and I think this would give me the mild but higher HP and torque I'm looking for. Also, could I use a cam like Doc's 20RV10M-212 RDP Cam (254) without modifying it? Would that be a good choice?

Finally, if I built it like this, would 9:1 still a good compression ratio to shoot for?

Thank you all again!

-Moose
Author:  Kevin Johnson [ Mon May 11, 2009 9:01 am ]
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Author:  Rug_Trucker [ Mon May 11, 2009 9:05 am ]
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I asked about the scraper here and was told it definately would work on the street.

Now this stroking thing is interesting!
Author:  MenkeMoose [ Mon May 11, 2009 9:17 pm ]
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I did a search on stroking to 4.4", and found that Ceej has done this. However he used 198 rods. {Doc's article strokes to 4.5" and uses 225 rods). Ceej also used Doc's RV15 rdp cam. I'm going to call Castillo's Crankshaft Service tomorrow to inquire about cost of stroking the crank, then go from there.

-Moose
Author:  Dart270 [ Tue May 12, 2009 8:07 am ]
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Hey, why not? Either type of rod should work fine, you'll just have to pick a piston with the right compression height. Might be good to just duplicate Doc's or Ceej's setup.

Lou
Author:  dakight [ Wed May 13, 2009 4:27 am ]
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I'm not going to get much into the technical details because I don't know enough about it. What I will say is to be sure to keep your goals in mind. he engine you're building is not for 1/4 mile high RPM, short duration runs. You're looking for something that will give you loads of bottom end torque and easy cruising. You want to minimize the cooling system load and maximize the low to mid RPM efficiency. These are different requirements than for a drag racer.
Author:  Kevin Johnson [ Wed May 13, 2009 5:56 am ]
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Author:  ceej [ Wed May 13, 2009 6:59 am ]
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I wasn't watching over here... I used Toyota pistons from the 90's four cylinder cars. That was with the 198 rods. The small end of the rod must be bushed down to match.

The pin height of the 88-94ish 3.0L V6 might be in the realm of possibility for a stock rod length. Take a look. The pin height is greater. Bore is 3.445 in the stock size. Coupled with the 4.44" Stroke, it might be a possibility for you. You will have to bush to the pin. The V6 piston is available cast, but not Hypereutectic. For your application standard cast should be fine, but the math needs to be done to see if the V6 piston will work. Rings are metric. 1.5-1.5-4.0mm. I have a full set of iron rings. They are relatively inexpensive.

The nice thing, if these pistons will work, is they come in a set of six! :D

CJ
Author:  slantfin [ Wed May 13, 2009 7:00 am ]
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Quote:
In higher education it is called longitudinal meta analysis between and within groups.
Niiice. I regret that I never got that high in my education. I did get plenty of the expensive kind of education that comes from doing it wrong. A common rookie mistake is to build for high end power, then try to drive the car to get groceries. Another mistake is to build a drag setup, and then try to get good highway mileage and good handling from a car set up to get a quick start, and go in a straight line. What Dakight said. The education starts when you start over.
Author:  MenkeMoose [ Wed May 13, 2009 9:42 am ]
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I think I've been pretty consistent with my goals. I've never intended to build a race motor. I simply want to gain as much HP and Torque as possible in a naturally aspirated engine. It needs to be durable enough to handle the load, and reliable.

The first thing a typical new Cortez owner wants to do is replace the /6 with a V8. Many have converted to a 318, however the necessary marine bell housing to do this is a rare find. The conversion also causes other issues with weight and heat.

I'm simply looking to create a build that gets as close to 318 power as possible, and that other Cortez owners could do, using readily available parts and not too much custom machining. Compared to the cost of buying a 318 and bell housing, building a 225 the right way should be doable.

Unfortunatley, I don't have the automotive skills to lay out the plan myself, so I read as much as I can here and elsewhere, and then try to get to an idea that works with some consensus from the experts.

I liked the K1/wiseco idea because they created new "off the shelf" performance parts. This seemed like an easy way to get more power with quality, durable parts.

Castillo's called me back this morning. They would charge at least $1300 to stroke the crankshaft (includes nitriding). Then I would still need to find a piston, rod and cam combo.

Is there any way to achieve the desired results I've described without stroking the crank?

Thanks again,

-Moose
Author:  SlantSixDan [ Wed May 13, 2009 10:16 am ]
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If your budget is wide enough open that you're considering custom crank and rods, I would respectfully submit it would be much, much more cost-effective to use stock crank/rods/pistons and put the money into a fuel injection (engine management) setup instead.
Author:  ceej [ Wed May 13, 2009 10:34 am ]
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Check around for a different source to weld up and stroke the crank. That's double what I paid. $500 to $700 is more realistic.

CJ
Author:  Kevin Johnson [ Wed May 13, 2009 10:43 am ]
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Author:  Dart270 [ Wed May 13, 2009 10:56 am ]
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I will say this again. By far the best way to achieve your goals is to put money into the head (big valves and porting). This also involves no fancy engine work in the short block (stock pistons, rods, crank, block...).

This will give more gains than stroking or engine management, or whatever else. I have played with a lot of mid-high output combos, and you can do very well with a stock short block, a mild cam, a 2bbl carb (350 or 500 cfm holley w/elec choke), and a very good head. 180-200 HP and around 250 ft-lbs is realistic with 8.5-9:1 comp and a mild cam upgrade. I have done this twice and these cars have run about as fast as a stock 318 would, and run like a stocker.

Specifically, I would try to get Doug Dutra or Mike Jeffrey to do a head for you, then either use the shortblock you have already, or rebuild one to stock specs at 0.030" or 0.060" over (include balancing of rotating assy and new rod bolts, new cast pistons). I would use a 220 @0.050" int and 212 @0.050" exh duration cam, like one of the RDP Erson grinds.

Based on what you've said, you don't want to mess with crank stroking and exotic rod/piston combos.

Lou
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