Can anyone tell me if a valiant 318 engine will fit into my 1966 dodge coronet that has a 313 poly engine in it now
magoo2,
Aug 18, 1:19am
Ive got a Valiant 318 in a 58 plymouth,so it must be possible
ema1,
Aug 18, 1:26am
x1
Yes they do as the later 1966 onwards "Intermediate" Dodge/Plymouth cars used the 318cid V8's. pretty much the same unit as the Valiant 318cid from Australia, which was USA sourced anyway. Some 1965-6-7 Dodge & Plymouth "Intermediates" used the 273cid V8 as well, as the Compact Plymouth Valiant & Dodge Dart's. Polys were pretty much on their way out by then, probably Chrysler Corp still had some on hand and decided to quit them in certain models. You would need to use the TorqueFlite auto box that comes with the 318 as well for ease of conversion. Slant 6 225cid 6 cylinder engines were also a base option on "Intermediate Mopar stuff including Coronets . Go the Mopars .good stuff. The "Intermediate Mopar cars had a wide engine choice actually right up to the famed 426Hemi and the 440cid 'E' V8's go for it I say as the later 318 is quite a bit lighter than the ole Poly jobs.
does the gearbox on your poly motor have the handbrake connected to it!
wayne1961,
Aug 18, 8:38am
Thats great, thanks to all for your know how ,the poly engine is a big heavy thirsty engine that does not offer a lot of power and parts seem to be hard to get so the 318 valiant engine sounds like it may be the way to go
cuda.340,
Aug 18, 4:13pm
actually the poly is a great torquey motor, the first V8 i ever built was a 313 poly. it has many advantages over the later LA 318 with better rocker gear, better ports, but yes parts availabilty is hard to find. if i were changing to a more modern small block i'd pass on the LA 318 & do a 360, fuel consumption is negligable but the power is much better.
wayne1961,
Aug 18, 5:08pm
Cheers for that cuda , I dont suppose you would have any idea where I could get hold of a 360 and auto trans or would a 360 fit up to my auto trans thats in the car now ,someone else I was talking to a while backreckoned a 360 might bolt straight in !
cuda.340,
Aug 18, 5:27pm
your bell housing will bolt up to the modern 360, as for buying one! i know of a 340 in christchurch up for sale but they want good coin for it. i've been watching e-bay & you can buy a built small block & have it landed with freight & tax for $5k if you want to import. performance ain't cheap no matter what marque you follow.
wayne1961,
Aug 18, 5:42pm
whats the condition of the one in Christchurch and how much are they wanting !
pdc1,
Aug 18, 9:17pm
When you decide which engine, check whether it is externally or internally balanced. I'm pretty sure the 318 is internal, and the 360 is external. Not sure about the 340, or the poly, but you will need the correct balance TC for the engine
wayne1961,
Aug 18, 9:32pm
Hi ema1, I checked the vin numbers on my car WH23 H4Y WP2W which indicates it is in fact a 2 door hard top it should be fitted with a 340 engine the colour is red and white and its year of manufacture was 1974 that all stacks up except its a 66
wayne1961,
Aug 18, 9:37pm
Thanks for that pdc1 but you hvelost me now ,Im just a simple electrician ha ha ,I know I lost my balance last night internally but I think to many rums had something to do with that ,thanks for your input
ema1,
Aug 19, 1:19am
Interestingly though is the 340cid V8 Chrysler engine is a far stronger engine than the 360cid, far more potential there though it's not as common as the 318 or 360. Interesting about the VIN codes there wayne. You want to check the engine codes to see if indeed it's a Poly in there! If it was to be a 340 then you'd have the best small block Mopar right there.
rob_man,
Aug 19, 1:28am
I've always thought that too, the 340 is to Mopar what the 327 was to GM.
pdc1,
Aug 19, 3:16am
some of these engines have balancing done by weights on the flywheel / torque convertor - some don't. While they may bolt up to transmissions and torque convertors, they have to be compatible with the way the engine has been designed in respect to balancing. Just something to be aware of to double check when you get you final combination sorted. The 340 is a great motor but usually commands a premium. ANother thing to consider is stroker kits. 318 can be taken out to over 400 cubes. Not sure whether you should discount the poly though. I haven't had one so don't know, but I've heard good things about them by people. Have you tried a few mopar forums e.g. www.nzmoparforum.co.nzwww.moparmarketforum.com
wayne1961,
Aug 19, 3:40am
Cheers for that Ill check those engine codes tommorrow and see if I can find out for sure what Ive got ,really gratefull to all you mopar enthusiasts for all the advice
ema1,
Aug 19, 6:44am
Say wayne.put up some pics of the engine if you can, would be interested to see what you have there.
wayne1961,
Aug 19, 6:40pm
Will do as soon as my son returns the camera do you have an email address I can send them to ,I cant see how to add them to here
cuda.340,
Aug 20, 12:29am
the 340 has the reputation mainly because there were no low performance versions, they all came with 4bbl carbs. the 340 go fast parts can all be fitted to a 360, all except the crank n oil pan. the 360 has the advantage of larger crank main journals which help with engines developing more torque, but unfortunately 360's only came with a cast crank. but with the stroker motor set up today, most stroker motors offer a steel crank to fit the 360 & with the thicker deck you get more cubes from a 360 block & it's a cheaper block to start with. i have a few 340's sitting in the shed, one day i might do something about it but in the mean time i'm slowly selling off the cranks, rods & pistons to folks who want stock stuff.
It's quite possible you have a Poly 318cid in your car as they went up to 1967 and the Poly 313cid only went to 1964. Both the Poly 313 and 318 along with 277 301 303 & 326 Polys were manufactured at varying times in the 1950's but only the 313 and 318 Poly's were carried on into production during the 1960's. They were called 'A' engines and the later lighter 273-318 340 & 360 small blocks were all called the LA range ( as in lightened "A" variants.) Actually the 340cid , (looking through my Mopar stuff from way back) were launched in late 1967 for the 1968 year. 273cid was the first of the LA Mopar V8's launched in 1964 in Mopar compacts and Intermediates, and modified substantially mostly in there inlet design before they went to the LA 318cid V8 in late 1967 for 1968 production year, but the 273cid V8 continued on alongside the 318cid V8 in some lines & markets until around early 1969. 318's 340 & 360 went on into the 1970's with various production changes in the 318 & 360 cases into the 2000's. The 340 was in limited production from 1968-73 only a 5 year run.
wayne1961,
Aug 22, 11:22pm
Hi there Ema 1 I found some numbers on the block one of them was on the front of the block 2532830the 8 may have been a 6 but fairly sure it was an 8 the other one was on the side of the block 10275with a one added bellow 1 I dont know if there is any where I can go to see what these numbers mean or if you can help with your untold knowledge of these old cars ,let us know your thoughts
wayne1961,
Aug 23, 12:27am
Found a site ,the number must be 2532630 this indicates a 318 A type engine so must be the last of the poly engines!
ema1,
Aug 23, 3:28am
Yup you got it. 318 'A' Poly last of those you have for sure. 318 LA will fit good but not sure of the engine mount differences, quite possible they could be made to mate up or perhaps mounts etc for the LA engines could be obtained from a later 1968-9 Dodge Coronet or Plymouth Satellite to suit. Perhaps if you check out a later car for whatever differences there may be in the mounting department for the LA318 that should give you a good idea, I can't actually say as I have never tackled a swap between 'A' Poly to LA Mopars. Grab the TorqueFlite auto trans that goes with the LA318 as well as that will simplify things dramatically. Guys in the Mopar Clubs should be able to help, even in the USA clubs might be able to "throw light " on the subject. Any case a good fabricator engineer would be able to sort it if you go the LA 318 way. Shouldn't be a biggie though. I must go check Google on the subject as you have me interested in what you are proposing. Cheers wayne1961
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