Valve Float or Points Gap

[RJRENTON]

With coil bind, something usually breaks, possibly a bent push rod(s)....if it's a flat coil surge damper it usually breaks likewise for an inner coil spring. However, I have no experience with CompCams "beehive" or variable rate coil design. Just asking a question...
BOB RENTON

 

[69L48Z27]

I would try a different dizzy and coil like R413 posted.
If the springs are matched to the cam , you checked push rod length , and have a little preload on the lifters.

whoa... did you check the install spring height and check for coil bind.
At upper rpm coil bind may be shutting things down ?

Unfortunately I don’t have another setup to try without taking another car apart. Push rod length is good and preload was set. Yes, all spring height and pressures were checked. Lift is just a tick over .600” with 1.6 ratio, no binding.
I have a set of springs in the mail. I’ll install those and see what we get. Seat of the pants says valve float but just wanted to understand what happens if points run out of steam at higher RPM. Springs used are old and I have no idea what their history is. It’s something I really should have just replaced when I rebuilt the engine in hindsight. <$150 for springs.

 

[yella71]

Do the easiest first. change the points.

 

[69L48Z27]

Well, here’s where we are. No better. Not the valve springs. Not the points and condenser. Not the coil. Looks like a fuel problem. Or, at least that’s where I’m headed next. Not one of those things changed anything, runs exactly the same.
One thing I learned is Napa still carries a ‘high rev’ points set.

 

[khryslerkid]

With your dwell meter hooked up read what it's doing through the rpms.

Do you have a pressure guage on your fuel line?

What carburetor, what fuel pump?

How many miles on the engine now?

Roller lifters or flat?

 

[1967coronet]

Well, here’s where we are. No better. Not the valve springs. Not the points and condenser. Not the coil. Looks like a fuel problem. Or, at least that’s where I’m headed next. Not one of those things changed anything, runs exactly the same.
One thing I learned is Napa still carries a ‘high rev’ points set.

Well crap.. anyway your going about this step by step so once found you will know what the problem was and thats good.
If your confident in your ignition system now and valve train { unknown spring rates still out there though } Time to check the carb floats and mabey raise them a little. What is the fuel pump ?
One more thing on the ignition......... I have had name brand plug wires that just would not carry the load at higher rpms ?

 

[69L48Z27]

With your dwell meter hooked up read what it's doing through the rpms.

Do you have a pressure guage on your fuel line?

What carburetor, what fuel pump?

How many miles on the engine now?

Roller lifters or flat?

Let’s see...
28 was dwell down low, I didn’t take it up over 2k.
No fuel pressure gauge yet.
1813 Edelbrock. FB Marketplace purchase used. Starting to wonder if this is why the carb was for sale.
Miles? Maybe 150 since rebuilt last fall.
Hydraulic flat tappet.

 

[69L48Z27]

Well crap.. anyway your going about this step by step so once found you will know what the problem was and thats good.
If your confident in your ignition system now and valve train { unknown spring rates still out there though } Time to check the carb floats and mabey raise them a little. What is the fuel pump ?
One more thing on the ignition......... I have had name brand plug wires that just would not carry the load at higher rpms ?

The valve springs are new and they are the one Hughes Engine matched to their cam.
Yep, floats and fuel pressure are next.
Fuel pump is a Carter stock replacement style.
Could be the wires I guess, no way to really diagnose that other than throw parts at it. They are new 7mm.

 

[1967coronet]

The valve springs are new and they are the one Hughes Engine matched to their cam.
Yep, floats and fuel pressure are next.
Fuel pump is a Carter stock replacement style.
Could be the wires I guess, no way to really diagnose that other than throw parts at it. They are new 7mm.

Ok I missed the new springs. One good way is to try a known good carb off another engine if available.
Wires sound like I am reaching lol but I have a new set of 8mm blue maxs with the header covers with a cable tie around them hanging on the wall just to remind me not to get another set.
Funny as it sounds I went to napa and bought a set of oem style beldons and still running them with fiberglass end boots

 

[1967coronet]

The valve springs are new and they are the one Hughes Engine matched to their cam.
Yep, floats and fuel pressure are next.
Fuel pump is a Carter stock replacement style.
Could be the wires I guess, no way to really diagnose that other than throw parts at it. They are new 7mm.

I just read the edelbrock carb ... Have you did a vacuum test on the engine ? wrong springs in that eddy will make rods float up and down, That and they are picky on float level.

 

[69L48Z27]

Ok I missed the new springs. One good way is to try a known good carb off another engine if available.
Wires sound like I am reaching lol but I have a new set of 8mm blue maxs with the header covers with a cable tie around them hanging on the wall just to remind me not to get another set.
Funny as it sounds I went to napa and bought a set of oem style beldons and still running them with fiberglass end boots

I have a Thermoquad I may throw on too.

 

[khryslerkid]

Let’s see...
28 was dwell down low, I didn’t take it up over 2k.
No fuel pressure gauge yet.
1813 Edelbrock. FB Marketplace purchase used. Starting to wonder if this is why the carb was for sale.
Miles? Maybe 150 since rebuilt last fall.
Hydraulic flat tappet.

Definitely check your float level. I've yet to find one that's set right when you open one up. While you're at it check the jet and needle sizes.

I like to see 32* - 34* on the dwell at idle. They can increase a little at higher rpms. Remember changing the point gap (dwell) will effect your timing. Recheck timing.

 

[69L48Z27]

I just read the edelbrock carb ... Have you did a vacuum test on the engine ? wrong springs in that eddy will make rods float up and down, That and they are picky on float level.

Yes, have 11”. This is happening at WOT. On and off the gas a little while hold gear and RPM doesn’t help either. Idle to 4500-5k the thing pulls hard. After that it’s like valve float. Pull the next gear and it recovers almost instantly and then hits the wall at the same RPM again.

 

[69L48Z27]

Definitely check your float level. I've yet to find one that's set right when you open one up. While you're at it check the jet and needle sizes.

I like to see 32* - 34* on the dwell at idle. They can increase a little at higher rpms. Remember changing the point gap (dwell) will effect your timing. Recheck timing.

When you have 30-32-34 dwell what’s the gap? I will say setting GM points dwell is nice with the window in the cap. Seems these you need to try different gaps to get to the dwell. I was at 26 and I closed the gap .001” @ .016”and it went to 28.

This is my first one of these carbs and if the floats aren’t right out of the box then it’s likely running out of gas. I assume when they’re low?

 

[33 IMP]

Well, here’s where we are. No better. Not the valve springs. Not the points and condenser. Not the coil. Looks like a fuel problem. Or, at least that’s where I’m headed next. Not one of those things changed anything, runs exactly the same.
One thing I learned is Napa still carries a ‘high rev’ points set.

Part number for the high-rev point set? (Is this for the factory single point, or dual points?) Thanks, John.

 

[1967coronet]

When you have 30-32-34 dwell what’s the gap? I will say setting GM points dwell is nice with the window in the cap. Seems these you need to try different gaps to get to the dwell. I was at 26 and I closed the gap .001” @ .016”and it went to 28.

This is my first one of these carbs and if the floats aren’t right out of the box then it’s likely running out of gas. I assume when they’re low?

You never know, I have seen them one float high and one to low. 11" a pair of orange step springs may be a good place to start. One more thing khryslerkid knows his stuff , he has helped me in the past when I couldnt see the forest for the trees. I had a 3 grand surge , 750 eddy , good ignition, he had me switch to ported advance vacuum. Worked for me.

 

[69L48Z27]

Part number for the high-rev point set? (Is this for the factory single point, or dual points?) Thanks, John.

Single
Order Submitted

CONTACT SET (POINTS)
Part #: ECH CS8510
Qty: 1
$7.43
$9.88 /each
- $2.45 Bucket Sale Promo

CONDENSER
Part #: ECH MO5000
Qty: 1
$8.79
$11.59 /each
- $2.80 Bucket Sale Promo

 

[33 IMP]

Thank you sir! Now I have to see if they are the same as the ones in my dual point (maybe?!). Thanks again for the photos, that really helps!

 

[69L48Z27]

I fairly sure dual points are different. Not positive though.

 

[RJRENTON]

When you have 30-32-34 dwell what’s the gap? I will say setting GM points dwell is nice with the window in the cap. Seems these you need to try different gaps to get to the dwell. I was at 26 and I closed the gap .001” @ .016”and it went to 28.

This is my first one of these carbs and if the floats aren’t right out of the box then it’s likely running out of gas. I assume when they’re low?

IMO...
EITHER use the dwell reading OR point gap. With a single point distributor, l always set the dwell to the lower of the FSM range of 28° - 32° to allow for rubbing block wear. The 28° dwell would equate to the ~ 0.016" point gap. THEN set the static timing to your preference and advance rate. Carter / Edelbrock (aka "eddy") carb's float settings are important but the critical dimension is FLOAT DROP, as this determines when and how much fuel begins to flow.
When renewing points on my Prestolite dual point distributor, i always pull the distributor ("dizzy") I set the point gaps to the 0.018". To me, its just an easier way to proceed. Then reinstall the distributor and set the static timing. Just my opinion of course.
BOB RENTON
AND YES....SINGLE POINTS ARE TOTALLY DIFFERENT THAN DUAL POINTS.
RJR