cadillac 472 re/build, phase 3: doing stuff

[dogsht]

Re: cadillac 472 re/build, phase 2: planning and discussion

Good deal on the HEI distributor. I would use it with the Crane adjustable vacuume advance kit plus I would replace the ignition module with the D 1941 because of how the Cadillac responds to a lot of initial timing.

Here is a great clip from Dave Brode about the ignition module & the Cadillacs desire for a lot of initial timing.

If the 5th pin sees ground, the timing retards. They were used for "smog" control. Iirc, to retard timing until the car was in high gear

The #1941 that I used retarded 5*. Some claims state that there were other modules that retarded a different amount. I used it to allow a bunch of initial timing. Over 20*, but I can't remember exactly, maybe 22*. My low compression engine with 232/240* at .050" cam liked lots of initial [anything with much cam will]. The module pulled 5* out when the starter was motoring, which prevented starter bucking. I drilled an extra hole in the dist, used a small grommet to run the extra wire.

Use a cheap common headlight etc relay. Run a wire from starter solenoid circuit, that "clicks" the relay. Run one of the switched normally open terminals to ground, the other to the 5th pin on the 1941. When said relay clicks, the 5th pin sees ground.

Sorry for the not too techincal terms. Here's an old thread, trapped in the abyss: index.php/topic,7447.0/topicseen.html

http://www.ebay.com/itm/NOS-1980-81-Bui ... es&vxp=mtr


I think if you do a good job with bowl work larger valves & a quality competition type valve job with either stock rocker system or better yet one of MTS's better ratio rocker setups so this sucker can breath you will love this motor. Don't be afraid to use some cam the motor is torquey in part because of size but also because of the high velocity heads & long stoke it comes in early and hard even with a lot of cam. It made my old 234/230 @ 50 cam seem mild & perfectly suited for a daily drive-able street car. Power in the rpm range you drive it & reliability with most all routine maintenance type items still available in most any parts store.

 

[G_Body_Enthusiast]

Re: cadillac 472 re/build, phase 2: planning and discussion

Good deal on the HEI distributor. I would use it with the Crane adjustable vacuume advance kit plus I would replace the ignition module with the D 1941 because of how the Cadillac responds to a lot of initial timing.

Here is a great clip from Dave Brode about the ignition module & the Cadillacs desire for a lot of initial timing.

If the 5th pin sees ground, the timing retards. They were used for "smog" control. Iirc, to retard timing until the car was in high gear

The #1941 that I used retarded 5*. Some claims state that there were other modules that retarded a different amount. I used it to allow a bunch of initial timing. Over 20*, but I can't remember exactly, maybe 22*. My low compression engine with 232/240* at .050" cam liked lots of initial [anything with much cam will]. The module pulled 5* out when the starter was motoring, which prevented starter bucking. I drilled an extra hole in the dist, used a small grommet to run the extra wire.

Use a cheap common headlight etc relay. Run a wire from starter solenoid circuit, that "clicks" the relay. Run one of the switched normally open terminals to ground, the other to the 5th pin on the 1941. When said relay clicks, the 5th pin sees ground.

Sorry for the not too techincal terms. Here's an old thread, trapped in the abyss: index.php/topic,7447.0/topicseen.html

http://www.ebay.com/itm/NOS-1980-81-Bui ... es&vxp=mtr


I think if you do a good job with bowl work larger valves & a quality competition type valve job with either stock rocker system or better yet one of MTS's better ratio rocker setups so this sucker can breath you will love this motor. Don't be afraid to use some cam the motor is torquey in part because of size but also because of the high velocity heads & long stoke it comes in early and hard even with a lot of cam. It made my old 234/230 @ 50 cam seem mild & perfectly suited for a daily drive-able street car. Power in the rpm range you drive it & reliability with most all routine maintenance type items still available in most any parts store.

ok so let me get this straight...i get a 5 pin module for the HEI and run the 5th pin to a basic relay and the starter solenoid and this will give more initial timing making it easier to start?

also i read somewhere (on some site or page about these engines) about simply pulling the hose to the vacuum advance. not sure that seems like a good idea. here's the paragraph on it...

The factory HEI distributor works fine if it is modified slightly. The stock advance curve is about as screwed up as any I have ever seen. For performance engines with over 9:1 compression ratio, the curve that seems to work well is 8 degrees initial and 25 degrees mechanical advance at 3000 rpm. For low compression engines under 9.0:1 CR, use 12-14 degrees of initial advance, and 20-22 degrees mechanical advance all in at 2500 rpm. This will give the motor low speed pep. Plug the vacuum advance. They over-advance and cause pinging. This distributor tip also works well in stock applications.

from here... http://www.crankshaftcoalition.com/wiki ... 0_Cadillac

also why a crane vacuum advance kit? something special about theirs? the one in the summit kit is adjustable too.

is a box like the 6A or 6AL a good idea or just a waste of money? i'm figuring on running v power NGK plugs but not sure on the wires, i havent looked into those yet. summit only has davis unified ignition livewires for 100 bucks a set. a bit too much for me.

 

[dogsht]

Re: cadillac 472 re/build, phase 2: planning and discussion

No Summits adjustable should be fine. Sorry rushed I just missed that it was adjustable. No if you do like the guy says and run 8 degrees and more initial the 5 pin module can be used to retard it 5 degrees only for start up. This makes it easy to start and eliminates kickback that occasionally can happen when using lots of initial timing. If and when it kicks back it often busts your starters mounting. No need to run a separate ignition box with a good ignition module. I won't say there is no benefit to running a separate ignition box such as a 6A box but that if you are not turning but 5,200 rpms at most the benefits would have to be very limited IMO. A multi spark is said to help clean up the idle a bit when an engine has a lot of cam & compression but its power saving benefits show up when you pass up what an HEI can function well at. Most seem the thing this would start to come into play above 6,000 rpms.

 

[G_Body_Enthusiast]

Re: cadillac 472 re/build, phase 2: planning and discussion

ok no box then. the points distributor happened to have a grommet in it for a wire giving me one to use with the 5 pin module so yay for me again.

also the flexplate is solid, apparently in 74 they started using them so i got lucky AGAIN. so i dont think i'm going to need to worry about it cracking or having to buy one.

now i'm slowly turning my attention to the transmission and seeing what i can do with it. i had the idea of keeping the 2.41 gear but changing the ratios in the th400 giving me better acceleration but not affecting cruising RPMs so i can still have that economy final drive. i'd like to rebuild the trans myself so i need a tech book or 2. since ive never used or had the intention of using a th400 i dont know enough about them right now.

slowly the wheels turn on this project. spend more time planning or more timing fixing and i hate doing the same thing twice (or thrice...) because i got it wrong and didnt do enough homework. i'm using a notebook to keep track of everything from inventory of parts to parts needed with prices so i can keep track of how much i'm spending/how much i need to spend.

 

[online170]

Re: cadillac 472 re/build, phase 2: planning and discussion

Maybe its cheap, but thats such a wierd way of going about it.

Starter kickback can be eliminated with a ignition throw switch. Crank crank crank, throw the switch to ON and it fires right up. You just need 2 hands and never worry about the starter.

If you want to get fancy with timing, have your distributer recurved (you would have to anyway to modify the curve).

With what that might cost, its usually cheaper to just get a capacitive discharge box or a fancy distributor. My 0.02.


Maybe im biased, but ive been spoiled with the goodies on the MSD 6AL-2 Programmable. Its so user friendly, you just open it up, create a totally custom ignition curve and have at it. Dont like the curve? Thats ok, you can adjust it every couple of RPM to 0.1* increments. Its pricey, but i think its worth it.



For what youre doing, id leave the distributor alone, Points OR HEI.

 

[G_Body_Enthusiast]

Re: cadillac 472 re/build, phase 2: planning and discussion

i dont want to get fancy with the ignition, i want to keep everything K.I.S.S. but if there are some simple things i can do i'll look into them and maybe give them a shot. if i dont need a part i dont want to buy it, it's far too easy for me to get carried away with it and buy more stuff than the project really needs to perform as intended originally. i just figure i'd rebuild the distributor run some NGK v power plugs and not sure on wires yet, the ones i usually use dont have them for cadillac engines so i may have to get a universal kit and go that route. stock wires are an option but aftermarket wires have always done better in my cars, maybe it's because i just stay on top of maintenance? at any rate i want it simple and for what i'm doing i dont think anything a step or two above stock is all that necessary BUT i should make sure the curve matches what the engine is doing to get the most out of it so i will need to curve it somehow. i just read about the 6AL2 on the msd site and it seems much more in tune with what i would like in an ignition. 410 bucks but it offers a much more flexible ignition in more than 1 way so the price is a smidgen high but it might be a better option.

i like K.I.S.S. but i also like having the flexibility to changes things to better suit what i'm doing and that's worth paying for sometimes. i'm not cheap i just like to make sure i get the most for my dollar and that i'm buying the best part for MY car/project/engine/transmission, etc. i'm not in a hurry to get things done so i have time to ponder this but i have to admit i like that box a lot.

what about this? http://www.msdignition.com/Products/Ign ... ntrol.aspx

it would do what i'm looking for and it's 330 bucks, 80 dollars less and no need to program it.

 

[online170]

Re: cadillac 472 re/build, phase 2: planning and discussion

Uh oh, maybe my computer has a virus, but I cant open that link. Do you have a PN for what youre referring to?


Can I ask WHY you would recurve your distributor? The cam you will be selecting is made to work as a stock replacement.

The most noticeable difference between points and HEI (other than having to adjust the dwell and points gap constantly) is the ease of starting and smoother idle.
-Points = crank crank crank crank----FIRE!
-HEI = cr...FIRE!

Similar gains if you go to a high output HEI coil, and similar gain AGAIN if you go to capacitive discharge box.


IMO, I would service the stock distributor HEI or Points and leave it alone.

 

[G_Body_Enthusiast]

Re: cadillac 472 re/build, phase 2: planning and discussion

Uh oh, maybe my computer has a virus, but I cant open that link. Do you have a PN for what youre referring to?


Can I ask WHY you would recurve your distributor? The cam you will be selecting is made to work as a stock replacement.

The most noticeable difference between points and HEI (other than having to adjust the dwell and points gap constantly) is the ease of starting and smoother idle.
-Points = crank crank crank crank----FIRE!
-HEI = cr...FIRE!

Similar gains if you go to a high output HEI coil, and similar gain AGAIN if you go to capacitive discharge box.


IMO, I would service the stock distributor HEI or Points and leave it alone.

the PN is 6520. the engine had a points distributor which surprised me but i read up that they used points till 74, half the 74 models got points, the rest got the HEI. no doubt using up their old inventory first causing this. but thankfully he gave me an HEI and it will be put into use. there's carbon build up in the combustion chambers, rather sooty. i'm sure the HEI will wake the engine up. the exhaust valve bottoms have a build up on them while the intake valve bottoms are blackened but they clean up rather easy. would polishing the combustion chambers do anything performance-wise? i have a thing for polishing metals and i figure the heads might benefit from a polishing all around. i'm also eyeballing the intake to polish its runners.


DIFFERENT SUBJECT: GAUGES

i have a question and hopefully someone can answer. i want to keep the stock gauges in my car but will the cadillac sending units work with them or will i need to use different sending units? please dont say to get aftermarket gauges. i'd rather buy sending units than spend more money on gauges if i dont need to. i know GM changed their gauges over the years and as a result not all sending units will work with all gauges so i'm wondering if i can make the ones for the caddy work.

and lastly i want to ask about multi port/SFI. how much would it cost to have fuel injector bungs welded to the intake? maybe use an EFI system that controls ignition too. rather than get in a hurry to just build the engine i'm thinking of just going slow and getting better components for it increasing the fun factor for the car. and it gives me plenty of time to do minor things with the block and other parts.

 

[Intragration]

Re: cadillac 472 re/build, phase 2: planning and discussion

The Cadillac sending units would have been for idiot lights, so they won't work with your gauges.

 

[online170]

Re: cadillac 472 re/build, phase 2: planning and discussion

The gauge question is a loaded one. For example you would need to determine the resistance range of your gauge, and the sending unit from Cadillac to compare if they work. I have no idea where to get those figures.

For fuel injection, I dont recommend Powerjection from Professional products. A freind has it and it has been nothing but problems. Quality is poor, service support isnt really there. You need sort out your own fuel pump, and the parts just dont seem to work together. Mind you it was developed in California, and we are using it in Ontario. When it works, it works like a dream, but it hasnt worked too often.

From reviews, I havent really heard anything bad about the FAST EZ-EFI from Holley.

Injector bungs, you are probably looking at 1hr of drilling and prep, 10mins per injector of welding, and probably 30-45mins of checking for quality and leaks. Cast is not fun to weld to. So 2hrs for an efficient shop, but custom one off's are never efficient so someone somewhere will probably spend 4-6hrs on it. For that price, just buy an MTS intakw with bungs in it already.