Gen 1 parts, Fitment and performance

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   Hello all!I am a new owner of a '56 Nash Ambassador special with the 250 v8. It will mostly be a custom cruiser, but I am a hotrodder at heart, so anytime I have to repair or replace something I feel the need to upgrade. 
It has been hard to find much info on these early mills, and I am new to AMC/Non Ford, so please excuse any dumb questions.
I see that the 250 had 3 power outputs: early 2v:190hp, Late 2v:200hp and 4v:215hp. Was there a compression difference between the early 2v and late 2v/4v? 

The car needs an exhaust, so I am naturally planning a simple dual set up, likely 2.25 or 2.5 with Smithy's mufflers. I have read that the exhaust manifolds for '63-'66 327 cars were revised for better flow. Would these be a direct fit? I know I will have to lift the motor to install, but I will likely be doing that anyways for fitting the Duals and to clean up and repaint the motor.

Will a later 327 4v intake work on the early 250 or does the 250 have smaller ports?

Lastly is there any source or interchange for a cam gear for these motors? I have heard to not trust the old plastic toothed gears, but only see cam gears and chains. 

Thanks!

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8ton Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Feb/21/2017 Location: Central VA Status: Offline Points: 34	Post Options Post Reply Quote 8ton Report Post Thanks(0) Quote Reply Topic: Gen 1 parts, Fitment and performance Posted: Feb/22/2017 at 10:55am
	Hello all! I am a new owner of a '56 Nash Ambassador special with the 250 v8. It will mostly be a custom cruiser, but I am a hotrodder at heart, so anytime I have to repair or replace something I feel the need to upgrade. It has been hard to find much info on these early mills, and I am new to AMC/Non Ford, so please excuse any dumb questions. I see that the 250 had 3 power outputs: early 2v:190hp, Late 2v:200hp and 4v:215hp. Was there a compression difference between the early 2v and late 2v/4v? The car needs an exhaust, so I am naturally planning a simple dual set up, likely 2.25 or 2.5 with Smithy's mufflers. I have read that the exhaust manifolds for '63-'66 327 cars were revised for better flow. Would these be a direct fit? I know I will have to lift the motor to install, but I will likely be doing that anyways for fitting the Duals and to clean up and repaint the motor. Will a later 327 4v intake work on the early 250 or does the 250 have smaller ports? Lastly is there any source or interchange for a cam gear for these motors? I have heard to not trust the old plastic toothed gears, but only see cam gears and chains. Thanks!

Buzzman72 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Sep/15/2009 Location: Southern IN Status: Offline Points: 2725	Post Options Post Reply Quote Buzzman72 Report Post Thanks(0) Quote Reply Posted: Feb/22/2017 at 1:40pm
	Heads and intake are the same. The small valves are a bit marginal for the 327 from a performance standpoint, but they're perfectly sized for the 250. I owned a '57 Rambler Super with the factory 250 and the 4-barrel WCFB carb and intake, and with factory duals (ceramic-coated). It was a decent performer. The old Hydra-matic lost 2nd gear, so I never knew its true potential...but with the solid lifters it would top out at 6000 rpm at 120 MPH and do it all night until you ran out of road. The heart-shaped chambers on the heads are a forerunner to the "Twisted Wedge" high-swirl chambers that were popular in aftermarket Brand X heads a few years back. The cam might stand to be improved. I've heard that Oregon Camshaft has Gen 1 cam billets, so you might want to see if they can grind you something close to the Lunati 250/256 dual-pattern cam that's available for the Gen 2/3 engines. Probably can't tolerate as much lift, but the cam grinder might have their own recommendations. The stock cam has a 244 degree duration, so a 250/256 would be a decent leap for that engine.
	Buzzman72...void where prohibited, your mileage may vary, objects in mirror may be closer than they appear, and alcohol may intensify any side effects.

8ton Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Feb/21/2017 Location: Central VA Status: Offline Points: 34	Post Options Post Reply Quote 8ton Report Post Thanks(0) Quote Reply Posted: Feb/22/2017 at 7:17pm
	So this may not change the plan much, BUT I think someone may have swapped in a 327. It has non-adjustable rocker arms, is painted blue/green with red valve covers, and, when I was fiddling with the distributor, I took the notion to look for the cast bore number. Between the dizzy, heater box and hoses, battery and firewall I couldn't lay eyes on it, but it felt like a single digit. If I am extra lucky I will already have the later model high flow manifolds. Is there any way to tell? Is there any way to tell which compression ratio pistons are in it?

Rebel327 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Nut Joined: Jan/26/2014 Location: Toledo Ohio Status: Offline Points: 358	Post Options Post Reply Quote Rebel327 Report Post Thanks(0) Quote Reply Posted: Feb/22/2017 at 7:48pm
	There is a lot of information on the 327 if you search this forum. If you have a 327, it will have only a 4 cast on block---since it is not Red, may be a 287 but those did not use same engine mounting scheme as 56, but you can make it work. The early exhaust manifolds have a "flat" area on them with the later manifolds being a better design. Get a later TSM and you will see pictures....or Google images on the web. Contrary to Rumor..Oregon Cams does not have billets, but they do have stock cores and can grind you a cam, or send yours in. The early 4 bbl intakes for 250 have been known to have smaller carb holes than the later ones. If you need it, I have a complete 327 from a 57 so I have everything including the trans. Also other parts to help you as needed. Good luck.

8ton Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Feb/21/2017 Location: Central VA Status: Offline Points: 34	Post Options Post Reply Quote 8ton Report Post Thanks(0) Quote Reply Posted: Feb/23/2017 at 8:06pm
	Thanks guys! I will grab a service manual ASAP. Are the reprints from Rock auto OK? The engine is in the car and seems like it will run well once I get it tuned up. No smoke no noise. Thanks for the offer, but I am TRYING to not be swapping engines/transmissions in this project. I will be doing an exhaust anyways, and a four barrel and cam are high on my list of wants. How big is the cast bore number? I feel maybe a 1/2" square back there. seems like one number. In the hopes of shedding light on what I have, I pulled a valve cover and got the part number from the passenger head and the intake, but now I can't find where I saw the list of casting # online. If anyone can decode them it would be appreciated! Head 3146596, two barrel intake 3746612. I can't seem to find any clear pictures of the early exhaust manifolds, and mine don't seem particularly flat, but it does have the 1956 factory style exhaust going from the drivers side, around the front of the oil pan, connecting to the passenger side outlet. The few pictures I found of the late manifolds seem to have more swept back outlets on both sides. Is this correct? Has anyone retrofitted a PVC valve to one of these early setups? I don't really like that it vents oil all over the back of the engine.

Buzzman72 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Sep/15/2009 Location: Southern IN Status: Offline Points: 2725	Post Options Post Reply Quote Buzzman72 Report Post Thanks(0) Quote Reply Posted: Feb/24/2017 at 5:58am
	IIRC, my '66 Marlin had a PCV valve plumbed into the rear of the valley pan. The ORIGINAL crankcase vent was the breather/oil filler cap at the front of the valley pan. Not sure why yours would be spewing oil at the BACK of the engine.
	Buzzman72...void where prohibited, your mileage may vary, objects in mirror may be closer than they appear, and alcohol may intensify any side effects.

8ton Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Feb/21/2017 Location: Central VA Status: Offline Points: 34	Post Options Post Reply Quote 8ton Report Post Thanks(0) Quote Reply Posted: Feb/24/2017 at 6:06am
	The rear of the valley pan has a 1 1/2" or so 90* pipe at the back, open to the world. I assumed it was a 'road draft' set up. If this is a newer motor, perhaps they just pulled the pvc out. It isn't really "spewing"-It just is really greasy back there from years of oily air coming out.

Buzzman72 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Sep/15/2009 Location: Southern IN Status: Offline Points: 2725	Post Options Post Reply Quote Buzzman72 Report Post Thanks(0) Quote Reply Posted: Feb/24/2017 at 6:25am
	That's the later valley pan setup. IIRC, my Marlin PCV valve was in a hose connected to that pipe.
	Buzzman72...void where prohibited, your mileage may vary, objects in mirror may be closer than they appear, and alcohol may intensify any side effects.

8ton Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Feb/21/2017 Location: Central VA Status: Offline Points: 34	Post Options Post Reply Quote 8ton Report Post Thanks(0) Quote Reply Posted: Feb/24/2017 at 9:56am
	Great, I see that RA has the valve and rubber grommet. So grommet goes in large pipe, valve in it, and 3/8 hose to a carb riser with port. That is easy. My intake is the early style with the small base 2v Carter carb. Since rebuild kits are so pricy, and the $30-60 for a carb spacer with port, I may justify doing a 4 barrel right off. I have been looking at adapting an aluminum one. Am I right in thinking I should aim for a performer or RPM intake vs the Torker/Single plane? Car is an automatic, and is mostly going to cruse to shows. It may get a mild cam in a year or so. ALSO: Is there a good way to tell what compression ratio I have? Will a standard compression test give any clues? Edited by 8ton - Feb/24/2017 at 9:59am

amcenthusiast Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jul/02/2012 Location: SW Atlanta GA Status: Offline Points: 1778	Post Options Post Reply Quote amcenthusiast Report Post Thanks(0) Quote Reply Posted: Feb/24/2017 at 11:04am
	I make XRV8 Race Parts. XRV8 Race Parts includes AM Warner Gear automatic transmissions.