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331 hemi in a 55, 56 Plymouth or Dodge Jump to page : 1 Now viewing page 1 [50 messages per page] | View previous thread :: View next thread |
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halosoldier |
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Member Posts: 17 Location: ocala, fl | What is the best way to install an early hemi in these cars. I know PAW made motor mounts for this but PAW has been out of business for awhile. I hear stories about using poly head 318 motor mounts with a slight modification. Butch's cool stuff has a swap kit for a small block Chrysler. Hot Heads has a motor mount kit for the early hemi. Or should I save myself a headache and just put in a small block Chrysler? | ||
Rodger |
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Expert Posts: 1506 Location: Colo Spgs | Hola John Is the vehicle an Manual or an Automatic ? Does it still have any parts of this ? Rodger & Gabby Colo Spgs | ||
hoodinki |
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Veteran Posts: 119 | Dodge and Plymouth changed their motor mounting designs from 1955 to 1956. Up until 1955, they had a single point mount under the water pump and wide rear mounts on bellhousing ears for standards and a special wing for automatics. In 1956 they flipped and put wide mounts on the front corners of the blocks of V8's and a single point under the bell housing for standard or under the tail of automatics. The rear cross members of automatic cars are removable, and far more aft of the standard transmission. The rear cross members for standards are welded to the frame. Why not just get a 1956 Dodge 325 hemi and bolt it right in? Fits in 55-56 Plymouth real good. A 331 offers not a whole lot more than a lot of weight. The 325 has dual quads available, and a rebuild can punch it up to 350 ci and a 9:1 compression. | ||
wayfarer |
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Elite Veteran Posts: 888 Location: Peoples Republic of Oregon | hoodinki - 2015-02-24 5:22 PM Dodge and Plymouth changed their motor mounting designs from 1955 to 1956. Up until 1955, they had a single point mount under the water pump and wide rear mounts on bellhousing ears for standards and a special wing for automatics. In 1956 they flipped and put wide mounts on the front corners of the blocks of V8's and a single point under the bell housing for standard or under the tail of automatics. The rear cross members of automatic cars are removable, and far more aft of the standard transmission. The rear cross members for standards are welded to the frame. Why not just get a 1956 Dodge 325 hemi and bolt it right in? Fits in 55-56 Plymouth real good. A 331 offers not a whole lot more than a lot of weight. The 325 has dual quads available, and a rebuild can punch it up to 350 ci and a 9:1 compression. Extreme over-boring any of the EarlyHemi engines is a recipe for disaster. You simply will not gain enough to compensate for the weaker cylinder walls. Period. You want more power ? use forged pistons and 10:1 c/r. Always, always, always sonic check each cylinder before doing any cutting. | ||
wayfarer |
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Elite Veteran Posts: 888 Location: Peoples Republic of Oregon | halosoldier - 2015-02-24 2:36 PM What is the best way to install an early hemi in these cars. I know PAW made motor mounts for this but PAW has been out of business for awhile. I hear stories about using poly head 318 motor mounts with a slight modification. Butch's cool stuff has a swap kit for a small block Chrysler. Hot Heads has a motor mount kit for the early hemi. Or should I save myself a headache and just put in a small block Chrysler? The EarlyHemi has virtually the same ears on the block as all of the pre-62 A series engines. The later LA ears only vary slightly so mounts can be made to fit the block w/o much hassle. If the subject car has side mounts then an EarlyHemi (except the 51-53 33) will be an easy bolt-in...as far as the mounts go. Clearance around other stuff will be another issue. RLTW | ||
halosoldier |
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Member Posts: 17 Location: ocala, fl | The car in question has an auto.trans thanks for the all the replies. The 331 hemi will have 10:1 comp.ratio, Isky cam, Arias pistons. The heads have been rebuilt using all Hot heads parts (good bunch of people in Low Gap, NC.) I used a 331 poly bock from a 56 Chrysler Saratoga. That means the block wasn't beaten to death. I've heard of people over boring these blocks to 354 cubic inch, doing this you end up with an expensive boat anchor. The Chrysler Hemi has a decent parts train behind it not so much for Dodge and Desoto. Oh yeah, I will be using a hot heads single4 barrel intake manifold, I will be using the chevy water pump adapters so the weight will be somewhat reduced. Msd billet distributor, Edelbrock carb I haven't eaten for weeks oh well hobbies can do that! | ||
Handygun |
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Elite Veteran Posts: 1117 Location: STL, MO | Powerflite has a post on putting a 700r4 in a 56 Ply in the Hot Rod section, he would be a good source on putting a Chrysler in a 56 Plymouth | ||
hoodinki |
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Veteran Posts: 119 | These engines were thick wall castings, there is a stupid amount of meat in the cylinder walls. The way machine shops handle the risk of an overbore is to bore it and measure the wall thickness. If too thin, then that cylinder gets a sleeve. But staying stock at 325 ci is better in any event. The 354 was a bored out 331. But I see you're stuck on using the 331, so never mind. I had a 55 Chrysler 331 hemi with a 56 Imperial Torqueflite on it and used an engine hoist to experiment with positions in the chassis of a 56 Plymouth when I had its body off. Not a good fit, it was happy nowhere. Too much weight, too wide, too long. Trouble with a Capital "T". So I wound up getting a stock 277 poly and finished it that way. | ||
Handygun |
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Elite Veteran Posts: 1117 Location: STL, MO | Machine shops around here usually sonic check the clock to check for wall thickness prior to boring, probably 180/120 max/min, something around there. Different builders have different preferences. Core shift is another issue. 331's and 354's are different castings. Personally I would bore to whatever cleans it up, leave as much material for ring seal and cylinder stiffness. 325 vs 331 the Chrysler will make more power because the head is better. | ||
wayfarer |
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Elite Veteran Posts: 888 Location: Peoples Republic of Oregon | hoodinki - 2015-02-26 3:54 PM These engines were thick wall castings, there is a stupid amount of meat in the cylinder walls. The way machine shops handle the risk of an overbore is to bore it and measure the wall thickness. If too thin, then that cylinder gets a sleeve. . More internet fallacy. The walls are not 'stupid thick' and they DO have terrible core shift issues. You best sonic check the walls before cutting unless you own stock in one of the sleeve companies. There is simply NO performance advantage to huge overbores but you are entitled to believe what you want to. | ||
Shep |
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Expert Posts: 3393 Location: Chestertown, NY ( near Lake George) | Well over boring will increase compression and free up some airflow but in daily drivers this is not a big deal, especially risking thin cyl. walls. Edited by Shep 2015-02-27 1:19 PM | ||
58coupe |
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Expert Posts: 1740 Location: Alaska | What is a safe overbore for these early hemis (assuming little or no core shift)? I have a 55 331 hemi that has already been bored to .040 over. Unfortunately, the previous owner did not take care of it and let water rust a couple of cylinders, I believe one cylinder will not clean up at .060 so I could have it sleeved. I also have a 57 354 poly that I believe has never been apart and would rather build that as a hemi. | ||
hoodinki |
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Veteran Posts: 119 | Some of us here don't know what we're talking about. I hope it isn't me. | ||
halosoldier |
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Member Posts: 17 Location: ocala, fl | Well if you're talking about me so what. I saw this swap done on a 56 plymouth , guy dropped a stock 392 Chrysler Hemi with some minor mods I wouldn't use an Imperial transmission. I forget what issue of Mopar Muscle , some person dropped a nicely done 392 Hemi into a 56 Fury and it looked factory. As far as overboring a 331 hemi just do it. A few guys I llistened to said if you want a 354 hemi get one. Those guys I'm talking about are Don Garlits and Gene Adams. I probably will use stock car exhaust manifolds rather than the truck manifolds. The manifolds will hurt power , that's ok I want to build something reliable and have fun. | ||
halosoldier |
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Member Posts: 17 Location: ocala, fl | Hoodinki, have you ever been on the Hot Hemi heads internet site? Some guy dropped a 354 hemi into a 71 Dodge Dart. You will find all kinds of stuff that seems impossible possible. Hot hemi heads, Lowgap, NC. Talk to Bob Walker and the good folks there. | ||
d500neil |
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Exner Expert 19,174 posts. Neil passed away 18 Sep 2015. You will be missed, Neil! Posts: 19146 Location: bishop, ca | And, FWIW, in the early 80's, during an engine overhaul, had my 325 '57 Hemi bored 40-over (to 330/331?) due to discovered corrosion in the cylinder walls, from the car's having been dead-stored, in Indiana, before I bought it. Absolutely no subsequent operational issues have ever occurred, from that overhaul work. | ||
Beltran |
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Expert Posts: 1730 Location: Michigan | John there is a happy medium somewhere. I think folks are just giving you the heads up that there are limits. Any overhauled engine is going to get some cylinder cleaning. I had my 354 overbored .30 to accommodate new pistons and clean up a tired old block. I also strongly recommend having yours line bore checked. Due to the fact that my block was a boat motor in a previous life, I had egg shaped mains. This was fixed by the machine shop (my second one). I have used a similar plan in my engine, same companies. I have extra parts for various reasons. If you care to bounce your plan off me for lessons learned, feel free to send me a PM and we can chat about it. I will be travelling the next couple of week but will try to check in on the web site. Edited by Beltran 2015-03-01 10:25 AM | ||
Mopar1 |
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Expert Posts: 3033 Location: N.W. Fla. | Somewhere on one of the sub-forums here there is a fairly lengthy thread on putting a 331 into a 55 or 56 Plym. Seems to me the OEM tranny cooler on the W/P had to be deleted, maybe a 392 center sump oil pan(needed that when I put a 331 into my '60 plym), The HH verticle oil filter adaptor won't work you need their OEM up angle one. A generic comment is most 331 can be bored to 354 std., but should only be done with a sonic check. As was said I'd go minimum overbore. "Wayfarer" is Quality Engineered Components, I've used his tranny adaptor to put modern 727s behind my 331 projects & really happy with them | ||
Mopar1 |
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Expert Posts: 3033 Location: N.W. Fla. | Used "A: Poly uppers & fabbed the lower mounts. | ||
halosoldier |
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Member Posts: 17 Location: ocala, fl | Here's another question on a 56 plymouth can a baby hemi front engine mount be used? The kind that is sold by Speedway motors part #135-5355. | ||
wayfarer |
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Elite Veteran Posts: 888 Location: Peoples Republic of Oregon | Assuming that you are dealing with a 241-260-270 with the oem front mount (and oem trans arrangement) then you can use the oem mount without spending money on the aftermarket piece. assuming..... If you are adapting a different trans and lose the bellhousing mounts then you have more work to consider. I'd be a bit hesitant to rely on the small timing cover bolts on the speedway mount if the rear mount is at the back of a TF or something. Just me....... | ||
halosoldier |
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Member Posts: 17 Location: ocala, fl | I know. I'm just trying to get some "education" by asking the good folks on this forum, because they have been there and done that. I saw a cool 55 Dodge on ebay with an injected 392 hemi that looked pretty boss. Like I have stated before my Hemi will be a 331 Chrysler Hemi with a trans adapter from Hot Heads for small block 727/904. | ||
hoodinki |
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Veteran Posts: 119 | Here's a Dodge V8-270 hemi that way installed in a 55 Plymouth convertible. Notice how in the later pictures the early hemi has been fitted with a crank vibration dampener from hemi hotheads and a later crank pulley of the bolt-on type. Edited by hoodinki 2015-03-06 7:02 PM (P1010219.JPG) (P1250018.JPG) (20130323_121327.jpg) (20130323_121321.jpg) (20130323_121243.jpg) Attachments ---------------- P1010219.JPG (90KB - 338 downloads) P1250018.JPG (95KB - 246 downloads) 20130323_121327.jpg (92KB - 313 downloads) 20130323_121321.jpg (97KB - 273 downloads) 20130323_121243.jpg (87KB - 270 downloads) | ||
halosoldier |
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Member Posts: 17 Location: ocala, fl | Great information with the pix. I do have that mount in my garage. I hope I don't keep throwing dumb questions. With that timing cover mount did you use a traditional transmission crossmember and did you fab the mounts on the frame that bolts to the timing cover engine mount? Thanks. That's the trouble with the speed of light: it gets here too early in the morning. | ||
Mopar1 |
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Expert Posts: 3033 Location: N.W. Fla. | halosoldier - 2015-03-07 10:26 AM The HH adaptor is a full circle design the Bob says is installed before you put the oil pan on. If you can't drop the oil pan when installed, you'd have to pull the engine/tranny together to get either out. The QEC one is a horseshoe style & it works. I'd think I'd cut the bottom off of the HH one to get normal access to unbolt the engine & tranny from each other in there are problems later.Great information with the pix. I do have that mount in my garage. I hope I don't keep throwing dumb questions. With that timing cover mount did you use a traditional transmission crossmember and did you fab the mounts on the frame that bolts to the timing cover engine mount? Thanks. That's the trouble with the speed of light: it gets here too early in the morning. | ||
hoodinki |
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Veteran Posts: 119 | This car needed to have its X-member 1955 Plymouth convertible frame replaced. I also wanted 3-speed overdrive. That car was originally an automatic with the removable rear crossmember. So a standard transmission 1956 frame was available and the X-channels from the original frame were transplanted into the replacement. The rear crossmember was the welded in type and had the single mount under the center of the bell housing. (That supports the engine when the transmission is pulled back for clutch service. I am unaware of any oil pan issues with this HH mount. I did fashion the mounting pads on the frame using standard pieces available from Speedway. I choose to bolt them to the frame, but welding them on may have been better. | ||
Mopar1 |
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Expert Posts: 3033 Location: N.W. Fla. | hoodinki - 2015-03-07 2:04 PM I was talking about the tranny adaptor being full circleI am unaware of any oil pan issues with this HH mount. . | ||
hoodinki |
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Veteran Posts: 119 | Rear mounts used up to 55. And How 56 was different. Edited by hoodinki 2015-03-09 11:33 PM (1955 Rear Mounts.jpg) (1956 Rear Mount Std Trans.JPG) Attachments ---------------- 1955 Rear Mounts.jpg (99KB - 260 downloads) 1956 Rear Mount Std Trans.JPG (98KB - 292 downloads) | ||
Powerflite |
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Expert 5K+ Posts: 9654 Location: So. Cal | halosoldier - 2015-02-28 12:41 PM ... I probably will use stock car exhaust manifolds rather than the truck manifolds. The manifolds will hurt power , that's ok I want to build something reliable and have fun. Looks like I am really late to this discussion, but... I have done this swap and made it work really nicely with the motor at the stock height, but shifted to the left to center the motor in the engine bay. It is likely that the reason hoodinki couldn't find a good place for the Chrysler hemi to sit in the '56 was because of the exhaust manifolds. You can't use any stock manifolds and expect it to work out well. You need custom headers or modified ones like I did. It is possible to use stock manifolds, but you have to jack up the motor and put the drive train at a lousy angle to make it fit. It isn't worth doing it that way. Have you made progress on your build? | ||
Mopar1 |
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Expert Posts: 3033 Location: N.W. Fla. | halosoldier - 2015-02-28 2:41 PM The 4 bolt truck ex mans will flow better than 2 bolt car ., basically what they used on the 300 cars. I probably will use stock car exhaust manifolds rather than the truck manifolds. The manifolds will hurt power , that's ok I want to build something reliable and have fun. | ||
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