cut123

First i wanna say im not up on ignitions. So im dumb about alot of the more technical stuff. Im putting the final touches on my 81 olds. it has a mild 403, cam ,flat tops,some head work. It has a newer hei looks like stock replacement. Ive been looking through summit at coils and different hei upgrade packages. My question is basically on a mild mainly street car that will see limited track time will i see any improvements in hoursepower and drivability. What upgrades do you suggest? I see some kits are around 300 bucks and to me if i cant feel it is the seat of my pants 300 bucks isnt worth it.

RetroRanger

IMO HEI is fine as it is i doubt you would see any gains w a higher voltage coil etc.

one thing that may help is to recurve the mechanical advance. many people say the mech advance should be all in by 3000 rpms.

Also it may be helpful to set the initial timing to somewhere between 15 and 20 ° if its not there already

total cost about $10 and you will feel it assuming its not already optimized

oldcutlass

The problem is that some of the higher voltage coils sacrifice amperage for the additional voltage. Most stock HEI's are good to about 6000 RPM which should be plenty for your application. Check your timing @ 34* @ around 3400 RPM with the vacuum advance disconnected, most engines like that setting. Then see where your initial winds up. Make sure you don't get any surging or ping with vacuum connected.

If you don't have an adjustable vacuum can invest in one with the above mentioned recurve kit.

Slomega

I'm running a SBC 355 in my 74 Omega, and the conversion to HEI was the BEST upgrade I've ever done.

....... I was never very good at setting points : )

redoldsman

For reliability and quick starting, it is a great upgrade. It was one of the first things I did on my 72 Cutlass in 1993. I have not touched it since.

RetroRanger

he already has an HEI

he is asking about upgrading the existing HEI

I also like the HEI I have one in my 72

BILL DEMMER

the only "upgrade" that i would do, is to make sure the timing and vacuum advance curves get the most out of your vehicle's total package.


bill

Intragration

I agree with Bill and Oldcutlass. I used the Crane recurve kit with the light springs and was very happy with it, big difference. Your stock weights and lighter springs might work for you too, depending on which ones you have. I was able to limit my stock vacuum advance to 10 degrees by making a small aluminum restrictor.

cutlassefi

The weak link on the HEI is really the module moreso than the coil. Change it to a good aftermarket one i.e. Accel, Mallory, MSD etc., and you'll be fine.

Olds64

I agree with the others. Invest in a recurve kit and an adjustable vacuum advance and you will be fine. No need to spend $300 when $15 will do just fine.

MX442

^^^^^^^^^
I agree... Save the $300 for the tires you're going to roast.

olds 307 and 403

The Accel super coil can be found cheaply, if you search around. I got a brand new one for $35. The MSD is a nice module but is getting expensive. Accel has a couple of modules avialable too. The Crane adjustable vacuum advance kit comes with 3 sets of advance springs. The fastest I could get full advance was around 3000 rpm. Unfortunately my HEI added a couple of degrees after 4000 rpm. I went with the Mallory magnetic beakerless billet distributor and 30450 Mallory coil. Full advance comes in at just over 1500 rpm with the lightest springs. Plus you can set it anywhere from 14 to 24 mechanical and various curves with the kit.

Fastbrianman

Weights and a vac can are a big improvement for cheap. I put a super coil on my first HEI conversion years ago and it seemed to fire up a little quicker when cold. I've been running them ever since.

Intragration

The point of adjusting vacuum advance as people are mentioning is to LIMIT vacuum advance. Otherwise with 35 degrees initial+centrifugal and a factory vacuum advance curve, you can end up with too much total advance in certain circumstances. An aftermarket adjustable vacuum advance or a homemade limiter don't provide additional performance, but they allow you to have more initial+centrifugal advance when they are most beneficial.

OldSchoolMuscle71

anyone recommend putting the HEI conversion kit that accel sells for about 70 bucks for my stock points dizzy? its a 350 2bbl. Ive driven the car for about a year now and noticed that efficiency has gone down the toilet. I tried adjusting them today with a .015 feeler gauge and just couldnt fit it in there so I was told to get a dwell meter. Advance auto parts was selling one for 40 bucks but i refuse to buy it lol if its worth it for 70 bucks ill go ahead and get the conversion kit. If not, what cheap HEI dizzy can i use that will give me improvement? Ive heard mid-late 70's hei's will work just fine but what else will i need? I'm tired of feeling less performance and shitty gas milage. I used to get 175 miles to a full tank and now I'm lucky to get 135-140.

oldcutlass

The right allen wrench is even less expensive than that! Advance autoparts probably has a dwell meter they rent or lend.

OldSchoolMuscle71

They tried to charge me 40 bucks for it lol it had dust all over the packaging from sitting. Instead my instructor today brought his digital multi meter with dwell option. Got it hooked up to my coil right now and it read 9 degrees lol no wonder it was running like crap. Ill set it between 28 and 32 and see what happens. Gunna try to time it correctly as well. I think the spec is 40 degree dwell..

oldcutlass

The spec is 30 on the dwell!

OldSchoolMuscle71

ok so I set the points with the dwell meter and it kept bouncing back from 30.7-31.2 ish. Felt better right away on start up and acceleration. Only one problem, now when the motor is under heavy load (stepping on it) Im hearing a ticking noise that goes away and comes back itermittently. I'm not sure if its pinging or the valves or ticking because Ive never heard this before my points were adjusted. Under normal acceleration and pick up i dont hear it but the minute i get on the gas heavy i start yo hear it. what could this be?

oldcutlass

Now you will; have to reset your timing. Remember dwell effects timing but timing does not effect dwell.

OldSchoolMuscle71

so do you think this is why Im hearing that sound?

BILL DEMMER

yes.


bill

OldSchoolMuscle71

Thanks for the info everyone I'll have that timing done asap