• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Timing for fun and economy - can it be done?

Share this page

RickB

RickB

Yoda
Offline
It's been a long, long time since I have looked at timing on any car.

I've decided that may be what's needed on my '70 BGT as it has some symptoms of the timing not being "right".
It could also be the valves need adjustment, but I'd rather check timing first.

This has a stock 1800 that was rebuilt, de-smogged, and seems pretty strong after a "wake up" from a 15 year nap in the PO's garage.

I'm pretty happy with the power I get out of the motor, but the valve train produces a bit of racket (not real bad, but audible) and the fuel economy is less than what I want after a full tune up.

When I look at the timing, where should it be? What's the 'sweet spot' generally on these motors?

Other thoughts about increasing economy while retaining power?
 
Its common to get some rattle in the mid-rpms due to fatigued advance springs in the distributor, which can offer way too much advance. Typically the best setting for your timing will be 10-14 BTDC at idle with the vacuum line disconnected from the vac advance. A good rebuild/recurve of the distributor may be worth up to 3-4 seconds off your 0-60 times. Its the kind of throttle response you'd expect from a cammed engine with a lightened flywheel! It should net you around 30-32 mpg in a well tuned engine with the factory HS4s.
 
So this sounds like if I were to switch out to a pointless system of some kind I'd be more easily able to get all I desire out of this engine. Is that the best idea?
 
So what exactly is the mileage you are getting that you're not happy with (and under what driving conditions)?
 
Rick,I had pretty much the same problem and along with it, my engine had a slight shake at idle that I could not get out. This is a totally rebuilt engine with everything new in it, including a pair of Hap Waldrop rebuilt SUs. Only thing left that could be causing my poor performance could be the distributor. So I bought a rebuilt dizzy from Jeff at Advanced Distributors and it solved all my problems. I get about 31 to 32 MPG, much more pep and the engine seems to relax rather than sound strained. So the distributor from Jeff and the carbs from Hap was the best money I spent on the car. My car is a 72 with the original point ignition. I wouldn't change it for anything! PJ
 
I get low 20's driving the interstate back & forth to work.
It's about 15 miles each way but I do warm it up a little before each direction driving to the interstate, then it's about 75mph all the way.
I've taken it out further, I'd say about 50 miles each way a few times.
You guys are most likely right about the distributor, the PO kept receipts and there's no record of anything ever being done with it. So a rebuilt original is better or at least as good as a new electronic setup?
What's the approximate cost for the rebuilt unit?
 
What about putting in a "Pertronix Ignitor Electronic Ignition Kit"? Coupled with a new Pertronix Flamethrower coil?
It's attractive in many ways, never worrying about the points is one of them.
I know some people here run with this setup, what's the experience here?
 
If your dizzy has not been rebuilt just think how old it is and how many miles it has gone. However, that said just think how well the thing works if it lasted that long.

I would point out that rockers and rocker shaft need rebuilding as well just due to advanced age.

Seems like I saw $100 bucks plus or minus some place for a rebuild.
 
I looked on Ebay & found a bunch of sellers hawking rebuilt distributors for MGB - hard to know who to trust.
Or I could get a Pertronix insert for my Dist.

The PO did supply me with receipts showing the head work, including the new rockers and assembly.

It's nice being the third owner, when the PO kept records for over 20 years. Like looking back in time. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif
 
Try contacting Jeff at https://www.advanceddistributors.com/. real nice & helpful. There is a curve worksheet to fill out & send to him for your needs & his prices are good. I just sent my TD dizzy out on Monday but I'm hoping it can be saved as it was a mess.
 
Here's what lead to this line of thinking.

I found that the idle would drop off after about 7 to 10 seconds whenever I tried costing downhill. I thought this was weird.

I did the usual stuff, tuned things up, cleaned out the fuel bowls, checked the floats. There was accumulated sludge in the bottoms of the bowls, which is now gone. However the "problem" remained.

Then I adjusted the little dial/knob on the side of the distributor that advances or retards timing.

I advanced it a bit, the rpm at idle picked up to about 1500 and I turned that down to 1100 at the idle screws.

The coasting stalls stopped, it just continues idling.
Now I think I should be doing something with the distributor.

Maybe, maybe not.

It couldn't hurt if the thing is nearly 38 years old and hasn't ever been rebuilt.
 
RickB said:
It couldn't hurt if the thing is nearly 38 years old and hasn't ever been rebuilt.
Click to expand...

You said it, and it would be a good move, about $100.
 
/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif

Now my remaining question is whether or not it's worth it to switch to the Pertronics unit that fits in the Lucas distributor or stay with points?

There's no doubt that the coil has gotten weaker with age, so coupling the Pertronics Ignitor kit with a Flamethrower would likely give my engine some more pep.
Right?
 
RickB said:
It couldn't hurt if the thing is nearly 38 years old and hasn't ever been rebuilt.
Click to expand...

That got me to thinking that my distributor was rebuilt recently, but then I thought a little more and realized that it was 19 years ago!
 
Hey Rick,

Get Jeff to go through the distributor first. Once it's up to snuff, then decide if you want to spend $ on the Pertronics. Unless the distributor is working right, you will just be throwing money at an unsolvable problem.

Jeff (Advance Dist.) did mine and it made an unbelievable difference. It was curved for my motor. It was like someone kicked it from behind!

I put a Pertronix on one of my cars and I can't tell the difference. It doesn't pull as hard as the one with Jeff's dist and plain old points. I don't have to adjust points but if it dies on the road, I'm SOL so I still have to carry a spare distributor plate.

Also, IMHO, if the coil works, it works. If you can get a bluish spark to jump about 1/4" you're good to go. If the spark is orange, then replace it.
 
This is my winter driver, when the weather warms enough I will switch back to my Midget. That's when I'll be able to get this distributor rebuilt. Unless he sells rebuilds and then credits back when you send in the core?
I could see buying one, replacing mine and then sending mine in to him.
 
RickB said:
Unless he sells rebuilds and then credits back when you send in the core?
I could see buying one, replacing mine and then sending mine in to him.
Click to expand...

Jeff's super easy to deal with. I'm pretty sure you could do that. You might send him a PM. (He was the first to respond to your query anyway.)

Re: winter driver... I'm still looking for the right BGT!

Good luck!

Adam
 
Thanks Adam, you know I read his response and didn't put that 2+2 together until you just mentioned it!
 
Back
Top