Tech Info: Cadillac OHV V8's 1949-1962

I realize I posted this a few weeks back,but thought for tech week I would post again...

I know alot you know this info already,but I have received a few emails about Caddys and thought I would write a post on what I know and remember about Cads regarding what interchanges through the years and different engines.I'm by no means an expert,I built mine in 96-98 and did as much homework as possible during that time,I was virtually clueless.I wish I knew alot of this info myself before I started into it.I learned alot from guys like Squeak Bell and other ex-racers who swore by the old Cads. So here I go...
First year was 1949 the CID was 331 OHV V8, also the same year the Olds 303 came out.From 1949-1962 this design engine was used (49-55 331CID) (56-58 365CID) (59-62 390CID)All Intake Manifolds,Camshafts,Water Pumps(diff outlet locations vary through the years),Valve Covers,Heads,Valley Covers will fit on all models(Studebaker rocker arms will fit also)(valley covers will fit up til 1967)(6x2 intakes will fit until 67).The first 1949 models had valve covers like the Olds and are pretty rare now.1949-51 had some real small exh ports and small valves,all 331's didn't breathe too well.Also compression was low on these like 7.5:1 and only had a two bbl carb until 52. 6 volt until 53.1949-1954 Cads were offered in manual also,and can be identified by the partial bellhousing cast like a Flathead Ford/Merc.They used the same trannys from 37-54 including La Salle,Olds,Buick..they all will bolt up the tailshafts are different etc.Oldsmobile shared the same set up until 1956.The 331's could be bored out alot up to a 1/4" but 1/8" or 3/16" is more practical.Basically a 390 is a bored out 331 and 390's can't be bored out that far.All Cads use non-adjustable rockers which limits you on any type of performance cam,adj rockers are a must in a performance motor and still can be had,just let me know(stock valve covers will not clear,either shim them up or use Edelbrock or Hildebrandt covers,Moons and Offys wont clear as well).All Cads 1949-1958 use a partial flow oil filtration system,the 1959 390 were the first to go full flow something to consider when choosing a Cad to build.Distributors are the same 1949-1954.All in all the 390 is the best for performance choice of them all, they look the same as the early models and will give you the cubes and compression tons of torque and horsepower!
Cadillac cool stuff..
Valve Covers-Early Factory Cadillac have the cursive script and were used I believe until 1955.Edelbrock and Hildebrandts are what you need for performance and clearance.Offy,Moon and Cal Custom made them alsffy and Moon are still available new.Finned valley covers are available from Dennis O'Brien of O'Brien Truckers.

Distributors-Everyone made them but are really hard to find now Du Coil,Grant,Spaulding,Rotofaze are the shit but good luck getting parts.Mallory Magspark was a great unit and the parts are still being made ie points,cap and rotor!Also Mallory will build you a new custom unit as will Vertex or Joe Hunt.

Pistons-I know Jahns and JE will build you pistons of any bore and compression,Jahns will only do cast though,but for the later mill ie 390's, stockers from TRW,Egge etc will work fine and give you 10.25:1, more since you will surface the heads.

Cams-Back in the 50's and 60's Isky made some cool rollers,and I believe there is someone making them again.My cam grinder wouldnt tell me who though! Cads dont like much more than .475" lift and 280 adv dur remember adj rockers will be a must at this lift.Can use Chevy lifters but need to have pushrods made,also can be done for like $8.00 a rod.The aftermarket Cad lifters are junk and made overseas.

Heads- 59-62 390 headsare the best and will bolt onto the earlier models no problem.Must use the rocker shafts from the 390.so make your mind up first about using adj rockers before you order them because the 331's are different than the 390's.as well as headers at this point eraly cads are small and rectangle the 390's are large and sq.the 390 can be fitted with Chevy 2.02 or 1.94 intake valves and 1.60 exh.to balance the flow properly leave the stock exh valves in the center two,because they are siamesed and share one large port.

Intakes-Cadillac made a cast iron 2x4 used 55-57 models as well as a 3x2 set up used on the 58-60.the 3x2 works ok but none of them really give you the performance you can get from a good aftermarket unit.The intake that flowed the best was the Weiand model 2x4's in the 60's that featured the large AFB carb pads the earlier versions were made for the WCFB small base and didnt flow worth a shit.The first aftermarket intakes were made by Detroit Racing, they featured a dual intake that really worked well as did Edmunds and Eddie Meyers,Offy, later a 2x4 was made this is more for a 331.3x2 intakes by Edelbrock or Weiand are the shit,sorry Offy!
3x2's seem to work well on Cads also.
4x2's Horne made the first they later became Cragar, pretty cool set up, but Edelbrock shook things up with a staggered design that delivered!
6x2's by Weiand and Edelbrock again rule especially the Dragstar by Weiand and the Edelbrock CA-6 they are high rise look bitchin,thats for all out balls to the walls throttle,one purpose only Fuel and more fuel.The Offy is ok but they are low rise only,Cragar made a cool low rise to.The 6x2 will fit the 63-67 390/429's as well, the deck width on these engines are narrower just cut the 5/8" fuel hose to fit and voila!
2x4's by Weiand in the 60's were the absolute best all round intake,Nicson,Detroit Racing and Maybe Edmunds made a 2x4 as well.
Blower intakes were made by Cragar I dont know if the rest made one or not,alot were just fabbed up..
Fuel inj by Mr Algon and Mr Hilborn were made good luck on that search.
Well thats all I got to say about that(Forrest Gump reference!)... Hope this helped some

 

Did you ever see that I posted that CD-694 4-2bbl intake was still availible? Are you still looking?

 

no i didn't sorry man..Kinda broke until I sell the Chevy..I do want it if you arent in a hurry!

 

I don't own it ...yet. It is about $100 more than I thought and I am in a similar $$$ situation, I have $, just didn't want to tie it up. Still trying to find a Mallory, Spalding, W&H distributor. I'll find one as soon as I tie up all my cash. I know of a Detroit Racing intake that is sitting too, may try to use the Edelbrock as bait. I'll let you know if I get it.

 

Marcus,
You done good, again!

warbird

 

And there was I thinking I was all alone in the world!
You guys don't know your born!Try living on the other
side of the Atlantic with your aged Cad motor.
If I might just add to Marcus' excellent posting
the 390 is a bored AND stroked version of the 331.
The 331/365/390 all share a common rod journal size
but the 365/390 cranks have mains .125 greater, which
potentially means that you can grind the 390 mains down
to the 331s 2.50 inches, bore the block (easy) to
4'' and have yourself a 390 in a 331 block.I have not
tried this myself yet but am mindful that 390 pistons
have to be used (higher pin in the piston) and there
are issues regarding the rear main seal (331 rope v.390
neoprene) but I'm sure it can be done (eventually) If
anyone out there has tried and failed I'd like to know?
By the by I've bored 3 331` blocks to 365 (old pistons
and Ford 4'' rings) with no bother at all in new unlinered
bores.
Valve cover issues I've covered in two ways.Firstly
the brutal method, where I aquired a pair of
Weiand alloy covers that had already had the valve
adjuster side hacked out, I had ally sheet welded over
the outside of the holes which gave the adjusters the
needed clearance. Method 2 was the cut up some adaptors
from 1/4'' ally and mount FE ford Cal-Custom covers.
(because I had them)Works fine.

 

Regarding the rope rear seal in the 331; there is a Mopar lip type seal that can be easily adapted. A lot neater than that leaky piece of rope. Now if I could do something about the ring of felt the early Cads used for a front main seal, life would be just a little bit easier.
warbird

 

Cool Thanks guys!!!

 

For Warbird.Re 331 felt seals.
I used the later front timing cover with the rubber seal
on my 331s and they work fine.What model Mopar uses the
seal to convert the rear rope job?
Roger

 

Thanks, what aa great post. I am about to go and pick up a beat up 49 caddie, and the 331 still turns. I was debating using the 331 or a nailhead in my 31 rpu, but with all the info, you may have swayed me to the caddie. Thanks again, I will definately mark this thread for further info. Thanks, Jay

 

Thats cool about the Mopar rear seal..Man I would like to know which one to use...

 

Just curious,,Did any of you guys use the oil slinger that goes on the nose of the crank on the 331? I built my engine and found that thing in a box of parts,I called a couple of guys on that and they said oh leave it out its ok!! Fuck that I pulled the timing cover right off and put it on there.If Cadillac put it there from the factory,I figured it better stay there.Better safe than sorry.**
Also on the road draft tube i cut it off at the 90 and put a grommet in place and installed a PCV valve.Should keep the inside sludge free.

 

[ QUOTE ]
For Warbird.Re 331 felt seals.
I used the later front timing cover with the rubber seal
on my 331s and they work fine.What model Mopar uses the
seal to convert the rear rope job?
Roger

[/ QUOTE ]

I thought the later front cover would probably work, but the one on my engine had been chromed long ago and I kind of wanted to keep it. The felt doesn't leak to badly, yet.

Here goes about the replacement lip rear main seal:

First credit where credit is due, I got this from Jack Hoffman from the Cadillac-Lasalle Collectors Club. Though they're absolutely NOT hot rodders, those guys answered a lot of my questions and were very helpfull. Do a search to find the web site.

Part number is a Fel-Pro BS40245, which is the rear main seal for a small block Mopar. When you take it out of the box, you'll notice that one half has a pair of wings or tits molded on that are used to locate the seal in the Mopar. Carefully trim these off; then clean the outside of both seal halves with alcohol or other solvent that'll cut oil but not hurt the seal. Cut a couple of 1/8" wide strips of .005 thick brass or steel shim stock and attach them to the outside of the seal halves using super glue. This is to increase the outside diameter of the seal for a better fit in the Cad block. This is the fun part; gluing a small thin piece of metal to the outside of the seal without getting yourself stuck! I cut the strips long, then trimmed them flush after the glue had set up well. Last thing is to goop up the outside of the seals with silicone sealer (important) and place them into seal groove in the block and main cap. You did pre-clean all this stuff didn't you? and remember that the lips face forward. Make sure that the ends of the seals fit flush with the cap and block, be sure to lube the seal lips, then install the crank and torque down the main caps.

I've got about 1700 miles on this set-up in my roadster with no leaks, so I'd say its worked for me.

I'd also recommend converting to a PVC valve as Marcus did as it'll put a negative pressure on the crankcase which helps keep the oil inside.
warbird

 

Awesome man!! Thanks a bunch for posting that!!

 

Just a Cad pic

 

Thanks Warbird!I'm going to try this one asap.I've
never had a 331 that didn't leak!
Can anyone i.d. an engine number for me?
Cad 331 of course.In the usual places i.e. rh front
block face and top of the bellhousing. # is 8M 88.
Had tiny exh ports and came in an Allard? Presume
its early but doesn't follow the conventional caddy
numbering sequences.
Next. I have a DRE intake with 2xWCD 2bbls.Fantastic
in a straight line, but woeful if you change direction.
I've done the rebuild thing and upped and downed the
floats to no avail.Any suggestions?

Thankyou/Roger

 

Great post Marcus! Don't forget about Wilcap adapters for hooking up a modern GM automatic to one of those mills, or a Bendsen adapter for running a modern manual slush box!

 

How about some shit like that on the 429`s ? come on somebody

 

Sorry caddyman...never messed around with any of that "new" shit....

 

Excellent f'ing thread! I've printed it as I'm building a 390 right now.

Thanks everybody!

 

Cadillacking is spelled with a 'K'

 

[ QUOTE ]
Great post Marcus! Don't forget about Wilcap adapters for hooking up a modern GM automatic to one of those mills, or a Bendsen adapter for running a modern manual slush box!

[/ QUOTE ]
Any info on bendsen adapters ???

 

If its so excellent How come I never get nominated?

 

Hey Caddilac people, I drug this old post up and wonder if anyone needs a Crager 4x2's intake, with 4 stromberg 97's, linkage and fuel lines to fit these Engines? The carbs are freed up but would certainly need kits. I think I will put it on ebay but I'm not sure what price to ask.. Its awfully awesome looking but it don't fit the 425 caddy I have.. maybe I'm lucky.. four carbs.. sucking..or leaking, gas.. Anybody?

 

Really you should be in the classifieds, but I'll ask anyway...what do you gotta have for it?

 

I've been looking for info on the feasibility of putting a Cadillac in a 51 Mercury and found the info posted below. I'm concerned about the engine hitting the steering gear of master cylinder so any guidance anyone can give would be appreciated.

While a later Cadillac wouldn't be exactly period correct, I'm leaning toward that just because I wouldn't need a trans adapter and availability of parts, speed and otherwise.

Bill Belmont's Rod and Custom has plans for the Hurst engine mounts but is currently out of them. Cost is $135 for mounts, $50 for brackets and $25 for biscuits. I understand that these are for early front mount Caddy engines, but I don't know what years they are or exactly what they look like.

Forwhatyouneed.com has Automatic Transmission conversion kits. $895

Transmissionadapters.com also has transmission adapters for stick and auto. $595.
Good forum!!! Ol Blue

 

Well, I do appologize for doing it this way, it seems I do a lot of things bass ackwards or I put the cart ahead of my horse, so to speak.

I don't want to get off-topic, but The intake is what Brought me to HAMB while doing a yahoo search on "Crager four duece intake" a couple weeks ago, so I joined and lost this thread, so I did yahoo again and HAMB forums popped up again, hense, Back door agiain to this thread.. so I posted this today. the intake has NO Numbers on it and I've had it for over two months now. It was a dad-burn revelation to find out that it fit an early caddy. there are a couple of rodders on here that have already expressed intrest in it..

I don't know what its worth, I was hoping to find out here, but I have sold a couple of 3x2's intakes on ebay. one flatty intake, no carbs brought $200.00 and the other tri-power vette brought over $1,700.00 . I didn't intend to run this as an ad here. But I am taking offers.

There are some nice folks on this forum. This is a very informative old post and I came in the back way sorta again. I didn't know it was Tec-week, but the originator of this thread needs a prize.. . I think I know what you'll say now, but maybe not

 

i am really interested in the pvc adaption for the down draft tube........ does anyone have any info on it or perhaps some pics of how they did it..............

and if it isnt too much to ask some part numers for the grommet and Pvc itself would be greatly appreciated

 

Thanks for bringing this one back up. I'm saving it. There are heaps of PCV threads on here. Just search and you will find a lot of info about how to do it.

Pete

 

This is still a great post