MCfan

Valves (20,000 psi)

If you mean between the door handle and the painted door, yes. At least mine did.

Geez, Davey, you risk making us old guys seem intolerant! Weren't we all young and foolish once, too? Young people that like cars (especially Montes) more than twice their age show an unusual level of good taste and maturity.

Hey, Tim, thanks for your suggestions. Color me out of touch, but I'd never heard of "Sea Foam" until I read your reply! I just read about it on their website - sounds a bit like "snake oil" but, as you say, it apparently works great! (If not, they sure have fooled a lot of people over the past 65 years!) I haven't solved this problem yet but I'm already learning a lot in the process. I can see this is a classic case of "barking up the wrong tree". For run-on to occur, there has to be combustion, however incomplete it may be. Even for partial combustion to occur, there has to be air, fuel and an ignition source. Without electric spark, the ignition source has to be combustion chamber heat. BUT, the heat won't matter IF there is no or insufficient fuel in the air to burn. So, instead of focusing on eliminating heat as the ignition source, I need to focus on reducing or eliminating the fuel entering the combustion chamber after the ignition is killed and the engine is still turning from rotational intetia. I appreciate the relationship between static timing and idle speed you suggested. I have always thought 4 degrees was low but that is what my GM service manual specified and I had no expereince or other specifications to the contrary. Early on, I had erroneously set the static advance between 8 and 10 degrees and I was getting a lot of pinging on acceleration. But that was before I worked on the advance curve with various spring combinations. This is probably all leading to a whole new tuning exercise with the objective to reduce the fuel coming through the idle circuit so when the ignition is killed there is less fuel to support ongoing combustion. Or something like that ... Thanks again for your suggestions. I'll probably try some Sea Foam first just to see what that does. I've never had much use for snake oil type products, but since it really works why not try it? Maybe I'll save a little to pour on my cereal in the morning ...

Thanks, Mark, I hadn't seen your reply yet. I will focus on adjusting the idle circuit as you suggested. I always shift into reverse before killing the engine because it's the only way to remove the key. So when I tried releasing the clutch to stop the dieseling the other night (with my right foot firmly on the brake, of course), the controlled lurch scared the $#%@ out of my wife - not a wise move under the conditions.

Thanks for the quick replies and suggestions, guys. Sorry, I should have given the current timing specs instead of just referring to the end results. I have and use a new Equus 5568 timing light and I know my current timing specs (which doesn't necessarily make them "correct", of course): Idles evenly at 800 rpm (after fast idle cam drops out) Static advance (low idle, vacuum advance blocked): 4 degree BTDC Vacuum advance: adds 17-19 degrees at idle Mechanical advance: adds 32 degrees, all in at 2600 rpm Again, just knowing the ignition timing settings does not make them "correct" but, whatever they are, they only have a DIRECT affect on engine operation when the ignition is ON, right? So, what is the INDIRECT or secondary effect of ignition timing that causes dieseling when the ignition is OFF??? I can see that ignition timing probably has a big effect on combustion chamber temperature which surely contributes to dieseling at shut down. Since the engine is always idling just before shut down, perhaps timing at idle is the likely contributor. If so, my total advance at idle (static plus vacuum) is currently only 21 - 23 degrees. That doesn't seem excessive to me, but maybe it is for this engine. On the other hand, the dieseling is alway "worse" (lasts longer) when the engine had been working harder/running faster so maybe it's the timing curve that's contributing to higher combustion chamber temperatures just before shut down. With my 3.31 rear gear and 28" tires, I get exactly 2.5 mph per 100 rpm so 65 mph is 2600 rpm and 70 is 2800 rpm, either of which should have the mechanical all in for a total of 36 degrees. Again, that doesn't sound excessive, but it may be for this engine. Sam, when you say 11:1 compression ratio is "nothing", do you mean it should not be a factor or contributor to dieseling? With no spark in the comubstion chamber, operating heat is the only other cause of combustion I can think of. The more compression, the hotter the compressed gas, of course (from Boyle's Law if I remember my physics correctly). I suspect that the combination of higher compression AND higher than normal/desired operational temperatures in the combustion chamber create the environment conducive to dieseling. Unlike electronic fuel injection, cutting off the fuel supply at shut down is not possible with the idle circuit still available mechanically. This engine simply does not idle well under 800 rpm but there may be something I could do with the idle circuit on the Edlebrock 1806 - need to read the manual. An excessively high operating temperature could be a factor but I'm running a brand new aluminum radiator, a 160 degree thermostat and a fixed factory fan blade driven off a 7 3/4" diameter crank pulley. My water temperature gauge confirms operating temperatures well below 200 degrees but maybe it was installed or calibrated incorrectly. There may be a simple fix, but if not, I'm just going to live with it. At least half the time it occurs in my driveway or garage anyway.

One annoying characteristic of my Monte's BB is that it often experiences "dieseling" or "run-on" for a few seconds after I kill the ignition. It is especially predictable and lengthy when the engine is "hot" from higher speed operation. I have always associated this with the higher-than-stock compression ratio of my engine (11:1 or more). Years ago, my brother-in-law had a '62 Impala with a 409 and it did exactly the same thing. It was bone stock but also had higher compression. I have never suspected other factors or modifications like ignition timing, cam profile/lifters or carb but I may be naive. I have always understood that "dieseling" occurs when the more highly compressed (hence hotter) air/fuel mixture is partially ignited by the temperatures in the combustion chamber even though the spark plugs are not arcing (i.e. when the ignition is off). Today, I stopped by my local salvage guy's place to pick up a rally wheel for my spare and he heard the engine diesel when I shut it down. He immediately commented, "Your timing is off!" Well, that may be - but it's news to me! This guy lives and breathes cars so I had to at least consider his opinion/diagnosis. Of course, he didn't volunteer HOW the timing was off and I didn't ask (primarily because the engine currently idles well, accelerates strongly and does not ping). I spent several weeks after I first got the car messing with my timing settings, vacuum advance on/off, switching centrifugal advance springs, etc. In the many test drives I took with all types of timing settings, the engine ALWAYS dieseled when I shut it down after an energetic run so it is difficult for me to accept that timing (at least in a normal operating range) is the cause or cure of dieseling. So what do you engine tuning pros think? Is dieseling something I just live with due to the compression ratio of my engine or is there some timing related cause or solution? BTW, it is not enough of an annoyance or embarrassment to cause me to run timing that adversely affects street or cruising performance. Any ideas or suggestions? Many thanks!

Holy smoke, Batman, she's already won the burnout trophy!!! That was awesome!! Best of luck to you both!! Hope one of you gets to run in the final 16! We'll be pulling for you both!

That shifter boot hold down flange is exactly like mine except the stock version is painted black. I replaced the rubber shifter boot a couple months ago and I am certain that flange is the same shape and size. My '70 is a factory 4-speed with console but I don't know if the floor cutout is the same for all console cars.

Dave, glad to hear that you both will be running a Pink's in Phoenix in mid November. Sounds like you have already registered. It would be great to see one of you on the TV program that will ultimately be aired from that event! I got some good feedback in a PM from a member who has participated and I've also done some online reasearch into Pink's. Seems you need to get their schedule well in advance of the target meet and then be ready to act immediately when their online registration opens for that event. The big "downer" I can see is that you could go to all of the time and expense to register, show up, ace the time trials and still not have a shot at the $10K grand prize because your particular ET bracket did not get chosen for the final 32 or 16 car run off. Most of the episodes I have seen on cable TV have featured the low to mid-10 second ET range but the one I viewed online last night from Dallas was the mid-8 second range. It seems to be a completely random choice by Rick and his buddies. Oh, well, life's not fair so why should this be? Within any given ET range, it seems that consistently reacting quickly to Rick's arm drop (without jumping) can be more important than having the fastest car. Interesting, too, that several do great in getting to the final round only to have their cars fail in the best of 3 "hot lap" competition. Maybe that's the producer's way of introducing an element of "Survivor" into their made-for-TV drag racing "reality" show? Driver's skill plus the car's performance and endurance are all a part of the winning combination. It will be great to hear about your first hand experience in November whether or not either of you gets chosen to run in the final elimination group. Best of luck to you both - we'll be pulling for you!

Congratulations on your continued success, Dave!! The videos are super!! First we get to see it all from the stands and then we get to ride shotgun - can't beat that for excitement! I'm just turning my attention back to drag racing as a spectator sport after a 40 year hiatus. I don't recall anyone on the FGMCC forums mentioning Pink's All Out. I get the feeling that is a variant of the sport's mainstream. It seems more organized and structured than casual racing, but not as formal as the NHRA meets. Do you or other members have any experience or opinions about Pink's that you care to share? Thanks for sharing your good news and videos! Best of luck in Arizona!

Kenny, if you're looking for "free" horsepower, releasing the parking brake is a great place to start!

Many thanks, Winston! The open sharing of technical knowledge and practical applications makes this club and forum extremely valuable to less experienced members like myself. I have been anticipating replacing my 3.31 stock gears with either 3.55 or 3.73 gears this winter after I install taller 275/60-15s on the rear in case I lose too much "zip" with my M20 around town. Your excellent photo documentary of how it's done certainly takes the mystery out of it and also reduces much of my former apprehension. Nearly 40 years ago, I allowed a local Phillips 66 station owner to replace a leaking pinion seal on my first '70 Monte. I headed east from Kansas City the next day and by the time I got to St. Louis the rear end was howling like a Banshee. After several hundred dollars and a day at the local Chevy dealer, I was back on the road. Later, the station owner admitted that he "forgot to properly torque" the pinion shaft nut so he reimbursed me for the labor and I paid for the new parts. I've never allowed a "service station" to do major mechanical work since.

I hope this is the proper forum in which to address this question. I am wondering if original factory parts are wanted/needed by restorers of Monte Carlos, even if they need to be repaired or refurbished? For example, I am in the process of replacing original shocks, brakes, radiator and gas tank on my '70 MC. Naturally, I just pitched the old shocks and brake parts, but I've hung onto the original radiator and gas tank (even though they both have minor leaks) wondering if some restorer might like to have them for authenticity (understanding they will need to be repaired/refurbished). Obviously, I don't know the "rules" for authentic restorations so maybe factory original parts are not necessary if newly manufactured identical replacements are available. Can anyone enlighten me? Thanks.