I am debating on going to HEI or not. I was wondering if I would do I have to change Timing and is the stock timing 10 BTC?

 

No the h.e.i deistributors offer a stronger spark timing is the same. The mechanical adv. might be a little diffrent but nothing to worry about if u stay under 14 degrees initial. I run an hei on my sbo 350 mildly built i run 14 initial . Just remember if you have stock points you cannot use the orignial reisitor wire it drops from 12v. to around 9 when hot. The H.E.I units need conctant 12 .

 

Ya the guy I bought it from had constant 12 volt power supply to the coil, I think that is why the points where welded together and when I was looking to buy it from him I told him that I wouldn't buy it unless it was running. It took us a hour and half to get it going, after sitting for two years! Once we had it going it didn't have very good spark. So when I got home with my new cutlass, which I fell in love with, I took the cap off and noticed that the arm, on the points, that moves when the cam on the disburter rotates around was just the stainless steel and no specail round metal piece on it, no idea what its called. This is why I'm debating on using the electronic replacement or HEI.

There was a couple of questions I forgot to ask was what is the firing order and the cylinder order on the block, sounds like a dumb question but I've never seen or heard anything about an Oldsmobile engine before just want to be sure .

I'm Leaning to keeping the original setup but want the high voltage and was wondering what the original coil specs are?

 

I dot know the specs on the coils i alwaya have run an hei. Btw there are some ebay hei units from procomp. I bought one ran it on the engine that used to be in my car that is now in my dads car I kept my proform unit. It worked great for 50 bucks cant beat it. You can buy the upgrade for it to go to non points like the pertronix ignitor 3 which is a nice unit but it had it's price. Best way to remember cylinder numbers is odd numbers are on driver side so 1 3 5 7 front to back and evens are on the right 2 4 6 8 front to back firing order is 18436572 and olds engines for the most part rotate counter clockwise

 

I've said this before to about a dozen people, so why not say it again...

If this is a new car, and you're just getting it going, why not just spend a few bucks on a new set of points and condenser, and a Mopar (perish the thought) ballast resistor, get it going good, drive it, and then decide on modifications and upgrades?

You can search for all the other times this question has come up here, and one of the things you will find is that you will not get any noticeable improvement in performance between HEI and a well adjusted set of points in a stock, non-modified engine. Yes, the HEI is better, but if you expect to notice your car running better and faster after switching to HEI, you'll be disappointed, unless there is something wrong with your present tuning, distributor, or wires.

- Eric

 

X2 ^^^^^^^^^^^^^^^^

 

i prefer the cleaner looks of the points style distributor but for a novice that just wants to poke a distributor in and go it is hard to beat the simplicity of the hei... it prettty much comes down to what you want to play with, points are as reliable as anything else, they just require a bit more time & effort to set up and then the occasional inspection & lubing of the rub block...

 

I like the hei for its simplicity and relatively low maintnance.

 

Those are two completely valid reasons to go with HEI.

I just want to make clear that my advice was based on the idea that he's just getting the car going, and switching distributors before he's got it up and running right might involve spending money that would be better spent on other things at this stage in the project.

I've got nothing against HEI, so long as the owner makes an informed decision to use it, and so long as he isn't "parts changing" in order to try to correct a problem that needs to be properly diagnosed.

- Eric

 

That is true an hei won't fix anything or make the car gain more performance . A stronger spark yes but not a massive hp gain. If his points are melted ect. Gettin a nice ebay hei will work good and its a completly new distributor. That is completly up to him .

 

With the HEI you need to change the initial the 20° BTDC @ 1100 RPM to make it happy. The HEI doesn't have as much mechanical advance built in unless you get the kit for it.

 

Maybe with stock hei ??? . My profomr unit came with a "performance" advance I had about 21 degrees at 1100 rpm when I checked the distributor curve that was with 14 initial at 800 rpm .

 

Thanks for the info, I wanted to stay with the original but I want to say good bye to points have had plenty of them. Also I not expecting a huge HP gain I understand what you have to do to gain noticable HP. One more question I swear when I look at the timing marks it didn't go up to 20, am I wright about this?

 

That could very well be.

They don't on the points style timing tabs. You'll either need to get a later HEI tab or a timing tape or use a dial back timing light to properly set the initial with a stock pointer.

 

points tab goes to 12° with the end of the tab being 14°

copper showed a pic in another thread where he marked his balancer out to 36° using the points tab as a guide. i used a dial timing light to see my intial then intial plus mechanical, then intial plus mechanical plus vacuum

 

I've timed vehicles before and I would just time it with the vacuum advanced hose pulled and plugged. Is intial the same thing? I also haven't heard of timing tape before, what does that all entail? What is the Distributor Curve?

 

inital timing is the timing in idle wit the vac. adv. disconnected. Total timing is how much total timing comes in and where with the vac. adv. disconnected. You need the timing tape to find out total unless you are using a dial back timing light.

 

Just ordered a HEI off of Ebay should be here in 2 to 6 days.!

One of you guys said to have the initial timing at 14 BTDC 800 RPM and another said 20 BTDC at 1100 rpm, I will try both to see which one runs better. The only thing is how does the timing tape work?

 

Initial on my set up is 14 at 800 rpm but i have a pretty rowdy cam. you should shoot for 12 arounf 650 rpm with stock stuff. Your mechanical advance starts to work around 1000 rpm. so at 1100 you will have roughly 20 degree with the mechanical advanvce working. With high performance distributors they usually advance as such you get around 8 degrees at 1000 rpm so 8 degrees mechanical plus 12 initial = 20 degrees total at 1100 rpm. The mechanical advanve will go up more as the rpm goes up so total timing on mine comes in at 3000 rpm a little soon but i get 32 degrees at 3k rpm.

 

Dont over think it install it . Set the initial timing and drive it and see how it drives. For most applications out of the box distributors are very close. If for some reason you feel the car is not running as it should or it has pinging then go back and check the mechanical adv. I used my out of the box proform hei on 2 mild engines before needing to recurve it and even then it was to gain max hp. still havent gotten it to the track to see if it will gain mph. On those two engines all i did was put it in set initial and drove it never checked total timing or the adv. never felt it needed it .

 

I disagree with the above posts and agree with SVNT442, HEIs "like" the timing around 20. Also, agree with MDMechanic, not only is there not a significant HP, there is NO HP gain
Also, I hope you did not buy an el-cheapo $50 unit, you will have more trouble with it than you ever would with your old set up.

 

Mine is actually at 20 degreed at 1000 rpm. My intial is 14 at idle on my proform unit . I did mention that . I also run an ebay hei on another engine on my dads car works great no issues .

 

I have read this many times. Can anyone explain why the HEI intial should/is more than the points ? I agree it is I just dont understand why.

When I got my car (HEI in it) it was 8° intial (rec for points) I have since bumped it to ~15° intial and recurved the dist the difference is as you might expect noticable. I had to stop at 15° becasue w the recurve and non adj vac advance I saw ~56° total at 4k RPMs future plans involve adj vac advance to limit that so i *may* be able to run more intial timing

To the OP initial is the timing set w vac advance plugged and at idle (~800rpms in my case) mechanical is the centrifugal advance determined by weights and springs in the dist many people taylor that curve to be all in (no more advance) by 3k rpms or so. total timing is intial plus mechanical plus vacuum advace (if you run vac advance)

 

I have used the Procomp 50k volt HEI in two engines. One of which makes about 450 hp, the other about 280hp. So far, the only drawback I've encountered is that the stock advance springs (the ones Procomp installed) were WAY to stiff for my higher hp engine. When the weather breaks, I plan to "dial it in" with different springs so I can change the advance and retard. The installed set-up is fine for most applications, but I feel I can make some improvements.
One other thing that nobody touched on, and it is minor, is the air cleaner/breather fitment. The larger cap will sometimes interefere with the back of the stock breather set-up on most applications---a small problem that is easily remedied.

 

ALL INITIAL TIMING SPECS ARE VARIABLE!!!!

Not all distributors have the same advance!!!!

ALWAYS time your engine at full advance. WHO CARES what the initial is, it does not matter!!!!!!!

OLDS LIKE 34-36 degrees full mechanical advance @3000-3200 rpm. Less mechanical advance = snappier throttle response = higher initial, ie HEI. Points = lots of mechanical advance, lower intitial.

DO I HAVE TO SAY THIS AGAIN???

 

I agree with MX442 to some extent. While I agree on adjusting the timing at full advance and agree on the 34-36 degrees with full advance at say, 3000rpm, I respectfully disagree on his base timing idea. Unless a high-torque starter has been installed, a hot (temperature) engine with too much base timing can be difficult to start with a stock-type starter and standard battery. I expect that if someone has that much engine where a couple of degrees of timing makes that big a difference, (I know mine both do) a good starter and well tuned distributor are probably in place. I would also say that running as much as 36 degrees at full advance would require better than low-grade fuel.

 

I agree with dave. My 350 roughly 400 hp needs 14 inital to be happy at idle at roughly 800 rpm. Then it all comes in around 3000 and i get 32 total that was with my out the box proform. I havent checket the curve on the pro comp. I actually compared it a few minutes ago. The wheights on the inside look like stock style h.e.i i had a stock gm one in the shop to compare to . Now my proform unit has a diffrent design and that holds true to what mx442 said and i agree that all mechanical advances arent created equal at least after market imo . I just installed an msd curve kit on my proform with yet again a diffrent design wheights havent checked the curve yet hopefully soon. I just think a stock engine is more forgiving with a out the box distributor than a built engine. According to crane cams literature "most gm hei's have 20 degrees mechanical advance" so if you have 12 inital plus 20 you get 32. where it comes in is where it will affect it . When you buy a curve kit from crane all it has is springs and an adjustable canister. It is designed to use the 20 degrees that comes on the gm hei and im sure their r&d department didnt make that satatement based on a assumption.

 

Wow! Thanks for all the info guys appriciate it. We are having some great weather here in Nebraska so ill have to wait untill that is over before I get to it. I feel prety confident about putting her in getting the intial timing and I guess I forgot to mention this before Im just look to leaving my engine stock power for know I just want it to be reliable and enjoy it stock then once I get board ith that then I'll rebuild! Thanks again guys I'll keep you posted.

 

Just for the record, points ARE reliable and they are more than adequate for 99% of the guys on here. Points don't fail any more often than pick-ups and modules do. IMHO. Electronic ignitions (solid state) showed up in the mid 70s. Guess what else did? Emission controls. (Yes, I know they were around before that, too). When points wear, dwell changes. When dwell changes timing changes. When timing changes exhaust emissions change. HEI and other factory electronic ignitions were initially designed and installed as a means to keep timing constant and thus control emissions. My .02

 

Also to be able to fire through leaner mixtures and wider spark gaps, especially when spark plugs were neglected, as emissions laws carried requirements that standards be met for a certain number of miles without maintenance.

- Eric

 

Sorry about the shouting, I get a little wound up sometimes. All I'm trying to say is that due to all the variables involved with timing advance curves, using a number at all-in advance, levels the playing field. It takes out the variables from one distributor to the other.

Disclaimer, with total in the mid 30*s and a vacuum advance of greater than 10 can be dangerous. So, I will back pedal and say that YMMV and your total number may be different, but low 30's all in is a good starting point.

Dave, that is correct, I'm not sure where you are disagreeing with me. Unless your distributor has less than 15 degrees of mechanical advance, I don't see this being a problem. And your right, 36 is going to likely require higher octane gas. I'm used to thinking in performance, high compression, and premium gas.

Distributor weights and springs change rate of advance.

The slots (travel) in the distributor define the total amount of mechanical advance.

 

Honest question here guys not being a smart @ss . Why is there so many diffrent wheight designs . I always thought the wheights had some factor that played into the total mech. adv. not just rate.

 

Copper, yes, aftermarket weights can alter the total advance also.. See below, I should clarify my statement. Different weight and spring kits sometimes have graph that shows the advance vs. RPM.

Here's a pic I stole from the net:

Weight and spring kits change the rate or curve. And, they might have bushings to limit the amount of total advance. Notice the bar between the weights. Each brand name may have different shaped bars. This also controls the rate of advance and may affect total advance vs stock weights. A dizzy with a heavy spring will require more centrifugal force to advance, thus higher all-in rpm. A heavier weight will advance quicker. By tailoring springs and weights, you re-curve the timing at different RPMs. So yes, a weight kit from Moroso, Excel, or NAPA might give you different results. Trial and error.

To make it easy, a good starting point for HEI is the stock weights with 1 light spring and 1 medium spring.

 

I know what the kit looks like and how the graphs work. Just didn't know if the wheights controlled total adv not just rate. I know my msd kit from what the paper work shows will have about 24 degrees if I read it correctly. So if I can get total in around 3400 rpm I need 12 initial which is what I am trying to achive now since my proform stock came in a little soon.

 

maybe the weights come into play to as far as total advance.

when I got my car it had what appear to be spectre weights in the dizzy. they are thin flimsy light units. The moroso kit I replaced it w had heavy weights very similar to stock GM ones. w the light weights I barely got any mechanical advance even w light springs w the heavier moroso weights I had to go to 1 light 1 mid spring to stop mechanical advance at idle

mx442 thanks for your explanation

 

The lighter the outside portion of the weights is, the less inertia they will have, and the less affected they will be by rotation, so heavier weights will advance the timing more and faster, lighter weights will advance the timing less and slower.

The mass of the weights will not affect the total advance available, it will only affect where it finally comes in.

- Eric

 

I set my timing at 20* at 1100 and the curve was 35* and it was fine.

I did gap my plugs to .060 instead of .035

 

Finally got the parts in the mail and time after work to put them in! Its a balmy 20 degrees here in Nebraska so time to fire up the nibco and rip in to here!

 

Well the swap went very well until I realized that my plug wires aren't even close to the same length. I bought it as a Kit, Ignition, Plugs, and Plug Wires. Majority of the plug wires are to short, is this the way its supposed to be because of the HEI?

Also does anyone know the length of the plug wires that go to each cylinder because I had them lieing out in order and my damn Dog got a hold of them. So they are not in order now.

What is the recomended gap for the spark plugs?

 

There has been some debate about ideal spark plug gaps.
I'd go about 0.045" with HEI.

As for the wires, just put 'em where they fit - I doubt the original set was cut "perfectly" either.

- Eric