Opinions on 327 timing setup

[Fuzz1957]

Would like opinions on timing for the 327 in my 57. Bought engine rebuilt with about 8-9k miles on it without intake, carb, distributor, and exhaust manifolds. Current Information: Block is 1963, bored .30 over, 3782461 double hump heads (1.94/1.50), Holley contender dual plane intake manifold (300-38 street dominator), Pertronix ignition, Edelbrock 1406 600 cfm carb, AC R45 plugs gapped @ .40 and 2.5” rams horn exhaust manifolds. Seller of motor can’t remember what cam it has - duh! Cam does have a pronounced lumpty lump. Can’t really get it to idle down lower than 900/1000 rpm without killing. Currently have timing set at 12* initial and 36* all in. Doesn’t get to 36* all in at 2500/3000 rpm like I want it to, but rather all in is 3500/4000 rpm and climbs up a little with higher rpms. I’m not a mechanic, but put most of this car together, and finding out I can do most things myself (I said most - not all). Had a mechanic set timing and carb a while back and it ran poorly - dieseling at shut down. Just redid everything myself yesterday with timing set as mentioned and it seems to idle/run better and doesn’t diesel anymore. Would like opinions and comments about setting up timing/carb from the very knowledgeable on this forum. Thanks in advance.

Fuzz

MAGA

 

[La Hot Rods]

What is the distributor, a converted original?

 

[Fuzz1957]

No, it’s a Pertronix that is built to look as the original GM small cap. Flamethrower II new in the box before being installed. Thanks again.

Fuzz

MAGA

 

[La Hot Rods]

Did it come with different springs for the advance, are you using the vacuum advance?

 

[Don Jacks]

Make sure that the Pertronix get full battery voltage[no resister].Then get a spring kit for that dist.and put lighter springs in there[I change one spring at a time] until you get the curve to come in to the rpm range that you want it to.The carb will likely be close jetting wise.Maybe a change in the power piston springs,depending on your engines vacuum.Do the dist. work first.Those older
heads like about 38 degrees total,and set the vac advance up to manifold vac to start.

 

[Fuzz1957]

Did it come with different springs for the advance, are you using the vacuum advance?

Yes, I believe it came with extra springs. Will check box.
Yes, using vac. Advance. Timing with it plugged off and using full manifold vac. off Edelbrock 1406 (driver side) when hooked up.

Fuzz

MAGA

 

[Fuzz1957]

Make sure that the Pertronix get full battery voltage[no resister].Then get a spring kit for that dist.and put lighter springs in there[I change one spring at a time] until you get the curve to come in to the rpm range that you want it to.The carb will likely be close jetting wise.Maybe a change in the power piston springs,depending on your engines vacuum.Do the dist. work first.Those older
heads like about 38 degrees total,and set the vac advance up to manifold vac to start.

Don,

There is no resistor - full voltage.
Have been reading up on distributor curves and wondering about this. Have never done anything like this before. But can’t be rocket science. I never assembled a car before either. While driving, power doesn’t seem to really come on until 3rd gear.
Haven’t really done anything with carb, except the idle screw and the two idle mixture screws at bottom of carb that only supply amount of fuel during idle. Do have the kit with all the stuff needed to change carb stuff. Again, have never done anything like this before.
Engine vacuum is low at idle because of cam, I think.
Thanks for your help.

Fuzz

MAGA

 

[Tooth]

O'Reilly's sells a kit with weights and three different spring tensions. You can make the Curve much faster with lighter springs and lighter weights and it will get you to your 2500 to 3000 total Advance quicker! I put the lighter weights on and one medium tension and one light tension on mine and it made a huge difference with throttle response! You can also use a vacuum gauge to set your idle and timing.

 

[Jim Sullivan]

Unless someone rewired the distributor, your battery feed to the coil is a resistance wire. As Don said, you need full 12 volts while running, to the coil. The resistor wire can be removed and a new wire run from the firewall connector to the coil or run a new, keyed feed wire to the coil.

P.S. To check for resistance wire- If you have a volt meter and test the voltage at the coil + side with the key on engine off, you will still read 12 volts. While running, it should read around 8-9 volts, I believe.

 

[Don Jacks]

It would be helpful to have the cranking compression too.What does the vacuum gauge read at idle?

 

[blkblk63ss]

Would be nice to know what kind of cam is in there ,but a vacuum test would be helpful too .

 

[Don Jacks]

I can likely get close by knowing what the cranking compression is and engines vacuum at idle.His 327's cranking compression with the stock cam should be around 165 psi.The more overlap that's ground into the cam the lower the cranking compression will be.To get this thing to suit his preferences,it may be necessary to change the cam for something more suitable.

 

[Fuzz1957]

First, thanks everyone for replies. Much appreciated.

Probably won’t get a lot accomplished in the next week. Hot and humid here and I can’t take it like days gone by. Will do what I can. Also, my Aunt passed yesterday, so that’s going to be another priority. Bear with me and please be patient with me to move this thread along.

1. The springs and everything are in the Pertronix box - unopened. Will have to read how to install. Would it be better to pull distributor or do it installed? It’s not easy to do “small work” reaching back there. I can see me loosing one or more of those little springs. What would you do?

2. Will redo vacuum testing. If I recall, did it with vacuum advance plugged and vacuum gauge hooked to full manifold port on carb. From memory (not always reliable) Ran about 13-15 at 1200 rpm idle. Went down as idle went down. Again, will redo and write it Down!

3. I’ve never done a compression test. Don’t have tester. Can buy or possibly borrow one. Is a cheap Harbor Freight tester OK for once in awhile use? Do I have to test all eight cylinders? Would agree that it would be nice to know cam specs. Not going to happen unless it’s taken out and that’s not going to happen right now. If I can get the engine dialed in pretty close to having some performance off the line and cruiseable - that would be great. Think changing the springs in distributor will go a long way to getting it “all in” by 3000 rpm. As a side note - just installed Autogear four speed - replacing my M21. Autogear has 2.98 first gear compared to M21’s 2:20. Really noticeable taking off from dead stop.

4. Jim - will double check wiring to coil as suggested earlier. Everything is newly wired AAW. No resistor used on firewall like chevys have.

Thanks again everyone. I know you guys know this stuff Waaaaaaaaay more than me and I really appreciate your willingness to help.

Fuzz

MAGA

 

[La Hot Rods]

Easy enough to replace the springs with the distributor in the car.
Just remove the cap and rotor, then they will be right on top.

 

[Don Jacks]

Sorry for your loss! When doing a compression test,remove all plugs.Yes an inexpensive tester will work,just get one that screws into the spark plug holes for more consistent readings.It wouldn't hurt to check all cylinders.Not only for readings but if there's a problem with a valve or cylinder you'll know know about it.Let us know whenever you get ready,or pm me for my phone number and I'll walk you through it.

 

[1958 delivery]

Easy enough to replace the springs with the distributor in the car.
Just remove the cap and rotor, then they will be right on top.

True, normally. I would not remove dist BUT getting old sometimes makes it difficult to do the little tedious things. Ask me how I know.
You haven't gotten there yet but you'll be finding out soon enough

 

[boxerdog]

I'd throw one light spring on it and go road test!

 

[blkblk63ss]

Wondering if it has the three slot crank timing gear and how they set it.

 

[Iowa 409 Guy]

Jim

Take a good look at the plugs when they're out.

If you're planning on driving over to Tri-state Raceway I'm sure you can have some hands on help in a couple of weeks.

Dave

 

[Fathead Racing]

With the timing set at 10 dgs with the vacuum advance plugged once you reconnect the vacuum pot hooked to manifold vacuum you should see the timing jump to 18 or 20 dgs. This should give you a nice clean idle. The small block 327s I worked on seemed to like 34 dgs. total all in by 2400/2600 rpm. Advanced timing at idle allows you to get a really good air fuel mixture adjustment which in turn allows you to back off the curb idle adjustment which gets the throttle blades out of the transfer slots of the carb leaning out the mix making for snappy throttle response. It's all good. Best way to set air fuel bleeds is with a vacuum gauge. I used to be the go to guy around here for tuning. Lots of free breakfasts from my buddies. Small block Chevy's especially responded to a good tune up because the engine was so well designed.