BN7 Starts after 25 years [but with problems]

[tahoe healey]

The springs are cheap at Moss. The dampers must be the right ones. Some have holes in the top black plastic (or brass)some don't. Just give Moss the model and they will get you straight. Again a cheap fix. All the other suppliers are good on these, too.

 

[JJS]

I disassembled the carbs and found a couple of possible issues.

The needles are correct for the HD8, "UH", but the jet is marked as a "100", Shouldn't the jet be marked with "125" for 0.125"?

The springs differ in length by about 1/2 inch.

I've ordered replacement jets and needles, springs, and a few other misc items. Can't hurt and should help.

Joe

 

[Dace]

Hi Patrick,
Sorry to hijack your response but as a BN7 owner who will be revisiting my ignition settings I was interested in your ""normal Healey Rules" quote.

Apologies if this is a stupid question what are the nornal Healey rules, knowing them may save me wasting time when trying to refine the setting on an already running car, albeit running rich,
Thanks
Dace

 

[Patrick67BJ8]

Hi Patrick,
Sorry to hijack your response but as a BN7 owner who will be revisiting my ignition settings I was interested in your ""normal Healey Rules" quote.

Apologies if this is a stupid question what are the nornal Healey rules, knowing them may save me wasting time when trying to refine the setting on an already running car, albeit running rich,
Thanks
Dace

Dace, There's the "13 rule" a lot of guys use in their 6 cyl. Healeys, but I use another rule for adjusting the valves. It's called "EOIC". <span style="text-decoration: underline">I will have to dig out my notes on this so I will post it later when I have time</span>, but it goes something like this: Adjust the Intake when "EO", Exhaust is Opening" and adjust the Exhaust when "Intake is just Closing". Again, I'll have to get out my notes on this writeup but this process was expliained to me by a machinest who used to do my Healey work when I lived in Florida a long time ago. It has something to do with making sure the valve being adjusted is at a particular point on the camshaft lobe.
This adjusting proceedure has always worked for me and I adjust my valves with the engine hot because that's where it "runs".
Patrick

 

[tahoe healey]

The rule of 13 is that the valve number being adjusted is subtracted from the number 13 to give the valve number that is in the down position (or open). This is counting form the front. Put the gear box in 4th (break off) and push the car forward by rotating the front wheel until you see the valve you are looking for open fully and adjust the one indicated by the rule of 13. I do mine cold cause that temp never changes where hot cool as you work. It really makes little difference to the end results.

 

[Patrick67BJ8]

Hi Patrick,
Sorry to hijack your response but as a BN7 owner who will be revisiting my ignition settings I was interested in your ""normal Healey Rules" quote.

Apologies if this is a stupid question what are the nornal Healey rules, knowing them may save me wasting time when trying to refine the setting on an already running car, albeit running rich,
Thanks
Dace

<span style="font-style: italic">Here's the formula from my June 3, 2008 post.</span>

Adjust intake valve when exhaust just starts to open,

Adjust exhaust valve when intake is closing.(almost closed)

This formula was given to me by a machine shop in JAX Florida when I lived there and overhauled several Healey engines. He was a very experienced machinest and was able to repair any thing I threw at him with Healey engines.
Patrick

 

[JJS]

I'm officially stumped.

I've replaced the carb dampers and springs, it helps a little with the chattering.
I checked and adjusted the valves if required.
The firing order and spark plug wires are correct.
I re-checked the distributor timing using the method in the service manual. And using the PHFFT method. Using the service manual method puts the TDC mark on the pulley at about 150 deg BTDC. (#6 cyl inlet just opening, #6 cyl exhaust just closing). Using the PHFFT method puts the TDC mark right on the pointer.

Symptoms - The car starts and runs at about 1,000 rpm. I cannot increase the rpm above about 1,500 rpm with the throttle at full (actually the engine runs even mmore poorly or shuts down with more throttle). I need to crack the butterfly a small amount to maintain the idle, it won't idle with just the slow running valve adjusted, the butterfly needs to be slightly open. I'm getting some backfire out the carbs.

I used a timing light with the vacuum line blocked. The car is a BN7, so shouldn't the timing at 600 rpm be 15 degrees advance? I'm seeing 25 just to keep it idling smoothly at 1,000 rpm. When I advance the timing to 35+, the engine runs really smooth at 1,500 rpm.

However, giving the car some throttle still won't result in the rpm climbing much above 1,500 rpm.

Thanks

Joe

 

[Randy Forbes]

My suggestion at this point, is to <span style="font-style: italic">sweet talk</span> Greg into stopping over.

Often times, you just need a different set of eyes to look at the problem. A fresh approach.

From what I've learned from Greg on this forum, you could do a lot worse :wink:

 

[JJS]

Thanks Randy,

It would be a bit of a drive for Greg, it's a couple of hours to Bakersfield from Santa Monica (assuming the 405 has not turned into a parking lot). I can load it on a trailer, but if I do that I'll take it back to the engine builder first to check the rebuild under his warranty.

I'm going to start a new thread (if that's OK with the forum policy) on just questions I have regarding the timing. Break the issue into small parts.

Thanks for the help,
Joe

 

[Dace]

thanks Patrick, much appreciated
Regards
Dace

 

[GregW]

Hi Joe,

I re-checked the distributor timing using the method in the service manual. And using the PHFFT method. Using the service manual method puts the TDC mark on the pulley at about 150 deg BTDC. (#6 cyl inlet just opening, #6 cyl exhaust just closing). Using the PHFFT method puts the TDC mark right on the pointer.

One thing to remember here is the position of the valves are reversed between the #1 and #6 cylinders. For #1 the exhaust valve is at the very front of the engine. #6 has the exhaust at the very back. Like bookends.

Symptoms - The car starts and runs at about 1,000 rpm. I cannot increase the rpm above about 1,500 rpm with the throttle at full (actually the engine runs even mmore poorly or shuts down with more throttle). I need to crack the butterfly a small amount to maintain the idle, it won't idle with just the slow running valve adjusted, the butterfly needs to be slightly open. I'm getting some backfire out the carbs.

<span style="text-decoration: line-through">I went through this thread again and noticed you were going to buy 125 jets. Do you have HD8's on your car? In the general data section of the manual (page: general data 13)all the pre BJ8s had 100 jets except for the tri carbs. The backfire through the carbs makes me think your lean, though I'd think 125 jets with 100 needles would make it reeeally rich.</span><span style="color: #3366FF">Nevermind, obviously I didn't go through the <span style="font-style: italic">whole</span> thread or I would have seen your first sentence</span>

I used a timing light with the vacuum line blocked. The car is a BN7, so shouldn't the timing at 600 rpm be 15 degrees advance?

Yes

I'm seeing 25 just to keep it idling smoothly at 1,000 rpm. When I advance the timing to 35+, the engine runs really smooth at 1,500 rpm.

How are you figuring the degrees, are you using a dial-back timing light?

 

[GregW]

Oh, one other thing. What was the answer for the oil in the dampers? Was there any, what weight oil did you put in when you were putting them back together?