What's normal operating temp of 351W?

[TinMan 77]

Yes.. I did search.. I know new engines like it hot... not 100% sure about old ones... I've read most folks fall into either the 180F or 195F camps. I get that.

 

My temp (and oil) gauges are not working. I have new sending units.. and they have resistance (temp once engine is warm)...  So I can't see where the temp needle "should be".

 

I've got a 180F thermostat.

 

Local radiator shop (specializes in older stuff) went through radiator and said it was in very good shape. I took off the installation clips so it was probably the first time off.

 

Timing is where it was last left 33 years ago when I parked it. I have not retarded it yet. I don't have a timing light, have no plans on buying one.

 

On a 85F day after 10 miles of mild city traffic (not real crowded here) it'll be around 205-210 at the thermostat housing... After 30 miles of mild city to cruising 45ish mph.. then sitting in 95F idling for a few minutes it was 225F...

 

Once she's about 210F, can't shut it off and let it sit too long as the gas starts to boil in the carb.. then she's unhappy starting.

 

When it's at 205F at the thermostat housing the upper hose near radiator and top of the radiator is 195ish.. bottom hose about 175-180F.. Factory stock shroud. Factory stock fan (exactly as it was when I parked it).

 

How hot is too hot (can't judge since gauge isn't working)?

 

Bottom end stock.. did have hardened seats put in the head.. TIA

[Alan_Mac 48]

I run my 418w with a thermocouple in the fins near the right side top radiator hose at 180.  

[ray1970 88]

Not shore how hot is to hot but it sounds like your running over all hotter than normal temp.

for your stile of driving.

Yes i know the radiator guy blessed it but you may want to think about a new 24 in. 4 core

in your future.....Or any radiator that is not 40+ years old..

[jholmes217 65]

With the lower octane gas these days, you should have your distributor recurved and bump the timing up.  My car likes between 14-16 degrees.

[barnett468 418]

imo, it doesnt matter how hot it gets if you don't care enough about your engine to get a $30.00 timing lite, but its obvious that your cooling system is insufficient for the amount of timing you are running, and part of this inefficiency is in the fan . your rad may also be too small . your t stat may also be stuck or need t be a high flow one.

 

all my cars can run 190 or less a all times in 100 degree heat with a 180 t stat.

 

no one can tell you how hot is too hot for your particular engine, however a safe rule of thumb is to turn it off if it gets to 220.

 

my 86 corvette is designed to run at 226 degrees with the factory optional cooling fan factory set to come on at 236 and the book says to turn it off at 240 . it got to 290 the other day when a fan failed and it is still ok.

 

your came with a 192 t stat

[Rsmach1 71]

#1. Get working gauges, personally I NEVER run an engine without a temp and oil pressure gauge.

 

#2. Invest in a timing light (you can get a cheap one for like $30 bucks), if you want to adjust timing you NEED TO HAVE ONE! Retarding an engine will make it run HOTTER. You want as much advance as possible without the engine pinging (detonation).

 

A 180° thermostat is perfect.

[TinMan 77]

Not being smart.. asking honest question... If you advance the timing won't it burn more of the air/fuel.. wouldn't that make it hotter? I'm struggling understanding this..

 

Background. I've owned this car since 1978.. parked in 1983.. just got it running about week and half ago... Money isn't issue for a timing light.. was a pre- response to a person that previously liked to pick a fight..  The marks on the balancer are gone anyway..

 

Haven't figured out gauges yet.

[Rsmach1 71]

You want all the fuel to burn, it's all about efficiency, retarding the ignition timing will cause an engine to work harder, working harder causes heat. Too much advance will cause detonation, this will cause heat as well, having as much advance as you can, without detonation, is where an engine will run most efficient.

 

As for your balancer, it will have timing marks engraved, you simply need to clean it off to find the marks.

 

Edit, a bad tune will cause an engine to run hot, be it timing, poor spark, fuel mixture.

[Rsmach1 71]

So having sat for so long 1st thing I'd do is a major tune-up. Cap, rotor, plugs, wires, and points if so equipped. What carb? Has it been rebuilt since it's been stored? Running lean can be another cause of running hot.

[TinMan 77]

Ok. I get it now.

 

I've cleaned the balancer.. but can't see any marks.. I've put at TDC and marked with white paint. I'm an old fat guy with bad eyes.. but I really don't see anything there..

 

Everything is new except P/S pump and starter. Heads rebuilt and hardened seats installed. Stock 2V carb, rebuilt with brass float. She runs pretty good.. just unhappy with anything over 1/2 throttle... backfires.. stumbles.. etc... All ignition replaced except module..

 

It could be lean.. Not sure how to tell... I did the run in the mixture screws until rough idle and back out 1/2 turn deal...

[barnett468 418]

i can tell you one way to set your timing to a level that is close to optimal for your particular engine but it requires good hearing or a timing lite and a tachometer which some timing lites have . some parts shops loan tools or rent them.

 

if you have points, set them from 016" to .018" with .017" being the spec.

 

if there was gas in it that was more than 6 months old, i would consider changing it.

 

remove the dist vacuum advance hose and plug it forever or until further notice.

 

if you have a holley style carb, set the gas level so it is just below the inspection hole while the engine is running or immediately after you turn the car off . put some paper towels next to the carb t catch any gas that comes out when you remove the inspection hole screws . if it has clear windows, set it so the gas is 1/4 way up while idling.

[DocWok 30]

Here's a trustworthy article on why you should not "remove the dist vacuum advance hose and plug it forever or until further notice."

 

TIMING AND VACUUM ADVANCE 101

The most important concept to understand is that lean mixtures, such as at idle and steady highway cruise, take longer to burn than rich mixtures; idle in particular, as idle mixture is affected by exhaust gas dilution. This requires that lean mixtures have "the fire lit" earlier in the compression cycle (spark timing advanced), allowing more burn time so that peak cylinder pressure is reached just after TDC for peak efficiency and reduced exhaust gas temperature (wasted combustion energy). Rich mixtures, on the other hand, burn faster than lean mixtures, so they need to have "the fire lit" later in the compression cycle (spark timing retarded slightly) so maximum cylinder pressure is still achieved at the same point after TDC as with the lean mixture, for maximum efficiency.

The centrifugal advance system in a distributor advances spark timing purely as a function of engine rpm (irrespective of engine load or operating conditions), with the amount of advance and the rate at which it comes in determined by the weights and springs on top of the autocam mechanism. The amount of advance added by the distributor, combined with initial static timing, is "total timing" (i.e., the 34-36 degrees at high rpm that most SBC's like). Vacuum advance has absolutely nothing to do with total timing or performance, as when the throttle is opened, manifold vacuum drops essentially to zero, and the vacuum advance drops out entirely; it has no part in the "total timing" equation.

At idle, the engine needs additional spark advance in order to fire that lean, diluted mixture earlier in order to develop maximum cylinder pressure at the proper point, so the vacuum advance can (connected to manifold vacuum, not "ported" vacuum - more on that aberration later) is activated by the high manifold vacuum, and adds about 15 degrees of spark advance, on top of the initial static timing setting (i.e., if your static timing is at 10 degrees, at idle it's actually around 25 degrees with the vacuum advance connected). The same thing occurs at steady-state highway cruise; the mixture is lean, takes longer to burn, the load on the engine is low, the manifold vacuum is high, so the vacuum advance is again deployed, and if you had a timing light set up so you could see the balancer as you were going down the highway, you'd see about 50 degrees advance (10 degrees initial, 20-25 degrees from the centrifugal advance, and 15 degrees from the vacuum advance) at steady-state cruise (it only takes about 40 horsepower to cruise at 50mph).

When you accelerate, the mixture is instantly enriched (by the accelerator pump, power valve, etc.), burns faster, doesn't need the additional spark advance, and when the throttle plates open, manifold vacuum drops, and the vacuum advance can returns to zero, retarding the spark timing back to what is provided by the initial static timing plus the centrifugal advance provided by the distributor at that engine rpm; the vacuum advance doesn't come back into play until you back off the gas and manifold vacuum increases again as you return to steady-state cruise, when the mixture again becomes lean.

The key difference is that centrifugal advance (in the distributor autocam via weights and springs) is purely rpm-sensitive; nothing changes it except changes in rpm. Vacuum advance, on the other hand, responds to engine load and rapidly-changing operating conditions, providing the correct degree of spark advance at any point in time based on engine load, to deal with both lean and rich mixture conditions. By today's terms, this was a relatively crude mechanical system, but it did a good job of optimizing engine efficiency, throttle response, fuel economy, and idle cooling, with absolutely ZERO effect on wide-open throttle performance, as vacuum advance is inoperative under wide-open throttle conditions. In modern cars with computerized engine controllers, all those sensors and the controller change both mixture and spark timing 50 to 100 times per second, and we don't even HAVE a distributor any more - it's all electronic.

Now, to the widely-misunderstood manifold-vs.-ported vacuum aberration. After 30-40 years of controlling vacuum advance with full manifold vacuum, along came emissions requirements, years before catalytic converter technology had been developed, and all manner of crude band-aid systems were developed to try and reduce hydrocarbons and oxides of nitrogen in the exhaust stream. One of these band-aids was "ported spark", which moved the vacuum pickup orifice in the carburetor venturi from below the throttle plate (where it was exposed to full manifold vacuum at idle) to above the throttle plate, where it saw no manifold vacuum at all at idle. This meant the vacuum advance was inoperative at idle (retarding spark timing from its optimum value), and these applications also had VERY low initial static timing (usually 4 degrees or less, and some actually were set at 2 degrees AFTER TDC). This was done in order to increase exhaust gas temperature (due to "lighting the fire late") to improve the effectiveness of the "afterburning" of hydrocarbons by the air injected into the exhaust manifolds by the A.I.R. system; as a result, these engines ran like crap, and an enormous amount of wasted heat energy was transferred through the exhaust port walls into the coolant, causing them to run hot at idle - cylinder pressure fell off, engine temperatures went up, combustion efficiency went down the drain, and fuel economy went down with it.

If you look at the centrifugal advance calibrations for these "ported spark, late-timed" engines, you'll see that instead of having 20 degrees of advance, they had up to 34 degrees of advance in the distributor, in order to get back to the 34-36 degrees "total timing" at high rpm wide-open throttle to get some of the performance back. The vacuum advance still worked at steady-state highway cruise (lean mixture = low emissions), but it was inoperative at idle, which caused all manner of problems - "ported vacuum" was strictly an early, pre-converter crude emissions strategy, and nothing more.

What about the Harry high-school non-vacuum advance polished billet "whizbang" distributors you see in the Summit and Jeg's catalogs? They're JUNK on a street-driven car, but some people keep buying them because they're "race car" parts, so they must be "good for my car" - they're NOT. "Race cars" run at wide-open throttle, rich mixture, full load, and high rpm all the time, so they don't need a system (vacuum advance) to deal with the full range of driving conditions encountered in street operation. Anyone driving a street-driven car without manifold-connected vacuum advance is sacrificing idle cooling, throttle response, engine efficiency, and fuel economy, probably because they don't understand what vacuum advance is, how it works, and what it's for - there are lots of long-time experienced "mechanics" who don't understand the principles and operation of vacuum advance either, so they're not alone.

Vacuum advance calibrations are different between stock engines and modified engines, especially if you have a lot of cam and have relatively low manifold vacuum at idle. Most stock vacuum advance cans aren’t fully-deployed until they see about 15†Hg. Manifold vacuum, so those cans don’t work very well on a modified engine; with less than 15†Hg. at a rough idle, the stock can will “dither†in and out in response to the rapidly-changing manifold vacuum, constantly varying the amount of vacuum advance, which creates an unstable idle. Modified engines with more cam that generate less than 15†Hg. of vacuum at idle need a vacuum advance can that’s fully-deployed at least 1â€, preferably 2†of vacuum less than idle vacuum level so idle advance is solid and stable; the Echlin #VC-1810 advance can (about $10 at NAPA) provides the same amount of advance as the stock can (15 degrees), but is fully-deployed at only 8†of vacuum, so there is no variation in idle timing even with a stout cam.

For peak engine performance, driveability, idle cooling and efficiency in a street-driven car, you need vacuum advance, connected to full manifold vacuum. Absolutely. Positively. Don't ask Summit or Jeg's about it – they don’t understand it, they're on commission, and they want to sell "race car" parts.

[barnett468 418]

The "article" posted above is FAR from trustworthy and should NOT be taken at face value . I have been building engines and tuning them for over 40 years and I know very well how to set the timing . That "article" is also inaccurate in some ways in that it leaves out some pertinent information . It is also irresponsible to tell someone to simply plug their vacuum can into manifold vacuum without first doing some testing to see if it adds too much advance at idle which in many cases it does.

 

Shelby's and factory 271 hp cars and several other fords and Chevy's did not have a vacuum advance from the factory, and the main purpose the vacuum advance serves is to help increase mileage . If your distributor is properly curved to give the optimum amount of advance for your particular setup, the amount of timing that you can use from the vacuum advance can is much less.

 

Also, there are several aftermarket cylinder heads available that have what they refer to as fast burn combustion chambers, and those heads require less advance than than a head with a non fast burn chamber.

 

FACT - Excessive advance can harm your engine . Not using a vacuum can will basically never harm an engine . I know this for a fact after doing this for a living day in and day out for 30 years plus another 10 years part time prior to that . I have seen literally hundreds of cars that had a bad vacuum advance can so it was not adding advance, and not a single one of them showed any obvious signs of trauma and they typically ran well other than sometimes needing a basic tune up etc.

 

This statement is simply hogwash the way it is written plain and simple and is also misleading.

 

"Anyone driving a street-driven car without manifold-connected vacuum advance is sacrificing idle cooling, throttle response, engine efficiency, and fuel economy,"

[ray1970 88]

Barnett I could not have put it better.

(Mosty due to poor spelling and bad grammar on my part..)

[TinMan 77]

Thanks for the help.

 

I've never heard of recurving a distributor. Is that just a different set of springs? Who sells them?

[Rsmach1 71]

Here's a write up https://www.fordmuscle.com/archives/2000/03/timing/

As for your balancer if you can see The TDC mark, you can always buy a tape with the marks and attach it to the balancer.

https://m.summitracing.com/parts/sum-163594?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-summit-racing&gclid=Cj0KEQjwte27BRCM6vjIidHvnKQBEiQAC4MzrUs9fhlzGjFt1BrJQZNSGGJ9VsegavzRwg5qtHENCiYaAm2g8P8HAQnot my thumb

[barnett468 418]

Here's a write up https://www.fordmuscle.com/archives/2000/03/timing/

 

 

And here is a brief excerpt from that article.

 

"The preferred vacuum source is the timed source. This way there is no effect on the initial timing setting. "

[Rsmach1 71]

And here is a brief excerpt from that article.

 

"The preferred vacuum source is the timed source. This way there is no effect on the initial timing setting. "

I would +1 but it might seem self serving as it came from a link in my post lol.

[barnett468 418]

I would +1 but it might seem self serving as it came from a link in my post lol.

 

Ok, I'll do it for you...+1

[barnett468 418]

Ok, I'll do it for you...+1

 

 

+2

[ray1970 88]

Not wanting to turn this into a dist. re curve thread.

You could make up a bench top dist re curve thingy with very little effort

Most of the time your just changing the spring rate to what RPM you want it all in by and how fast or slow

it gets there.

This can be done by anybody that HAS a tack and a good TIMING LIGHT.

Having some springs on hand helps a lot too..

 

This is the way I see it.

 

Me... I have gotten lazy and just push numbers on a key pad..

[Rsmach1 71]

OK, getting back to the matter at hand TinMan, because you stated you had hardened seats installed I'm guessing the engine has been rebuilt. Do you know if it was done stock? Any idea what compression? Stock or performance cam?

You will need a timing light, and if you can't see the the marks, the balancer tape. With the above info and the tools we can get started tuning (much more to come after this). As usual not my thumb.

[ray1970 88]

Tinman has his very own thread called-- It is time --that will tell you most every thing you need know about his motor and car for the last 40 years in the building forum.

[Rsmach1 71]

Ty Ray, off to check it out.

[Rsmach1 71]

So stock 69 351w 2v (very nice car and story btw), what octane fuel did you use?

 

Disregard the compression/cam questions.