Last post on Sep 10, 2007 at 7:41 AM
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#8 of 17 Re: Mid '70s cars and lead gas requirements [71chevyc10]
by MrShift@Edmunds HOST
Aug 13, 2007 (8:41 am)
If you mean 13-14 degrees at idle, that's too much.
Also with low compression you can't expect much--a cylinder needs a minimum of about 85 psi to fire. MSD wires and HEI only matter for very high HP engines.
Why don't you do a cylinder leakdown test and figure out exactly what you need? If it's just a head freshening, that's not too hard to do. If it's rings, you might think about buying a crate engine and just dropping that in there. Instant, cheap HP and a warranty for maybe $3,500.
Aug 25, 2007 (5:09 pm)
If you are worried there are additives out there. STP makes one,though it may be dropping the product as the latest batch I found [STP Unleaded Fuel Substitute], I found at Big Lots for 1.00 each.Some other companies offer it too... "101" something with all the octane boosters.
I use it in my 63 Valiant, though the engine isn't original. It may very well may have been from a 73 or later car which would have had the hardened valve seats or the upgrade at rebuild as the "new" engine was installed in 1988.It's only covered some 15,000 miles since then and my adding the lead subsitute has been erratic, but there have been no problems so far.
At this rate I will be worrying about finding any fuel derived from dinosaur squeezins by the time any problems might arise from using the unleaded.
CA phased out leaded fuel completely not long after that. Arco offered something called EC 1 that was made for cars that required leaded gas. Don't know what additive was in that.
You'll be fine. Just about everyone had gone to unleaded gas by 1975
and made the proper mechanical revisions, though Subaru and Honda IIRC had emissions controls that would allow a driver to use either leaded or unleaded to no ill effect. They had engineered them in such a way they didn't need catalytic converters to meet Fed standards.
#11 of 17 Re: Unleaded [dweezil]
Aug 27, 2007 (2:12 pm)
though Subaru and Honda IIRC had emissions controls that would allow a driver to use either leaded or unleaded to no ill effect. They had engineered them in such a way they didn't need catalytic converters to meet Fed standards..
IIRC my '89 Accord hatch had no Cat. Honda used a stratified charge lean-burn system called CVCC (Compound Vortex Controlled Combustion) to control emissions.
I won't pretend to know how it worked.
#12 of 17 Re: Unleaded [andys120]
Aug 28, 2007 (5:39 am)
Wow. All the way to 89. I didn't know that.
Honda started with that in the 70s and offered both CVCC and non CVCC Civics as well. Something to do with a 3rd valve, I think or a pre combustion chamber. I remember there were a couple of articles in Motor Trend at the time with lots of info and cut away drawings.
Apparently GM has developed something that ignites the fuel with out spark plugs, just using pressure. This eliminates a lot of emissions devices, runs cleaner, and imp[roves gas mileage. There's no unburned waste. It's in today's Car Connection.
#13 of 17 Re: Unleaded [andys120]
Aug 28, 2007 (5:57 am)
I thought that (CVCC) was during the '70s, with pretty much all cars switched over to unleaded and cats. They're listed for '89 Accords.
#14 of 17 Re: Mid '70s cars and lead gas requirements [Mr_Shiftright]
Aug 30, 2007 (7:36 pm)
ok so i have moved it back to about 10 degrees instead of 14 where i had it before. and it does run much better especially on the highway. so compression on the whole engine is about 120 per cylinder and about 95 on the 6th cylinder with the tapping noise. tapping meaning its probably the valvs. so it idles at 700-800 rpm and under load is abot 550- 600 rpm, is this normal? and it has good power from about 0- 30mph and even better power on the highway, it cruises at about 2700-3000 rpms on the highway going 60mph varing on the roads hills. so do you know if the rpm are ok at that speed. i drive about 20miles to school so about half hour on the roador more depending on traffic.
#15 of 17 Re: Mid '70s cars and lead gas requirements [71chevyc10]
by MrShift@Edmunds HOST
Aug 31, 2007 (6:33 am)
It idles a bit high....you might check for a vacuum leak somewhere. The noise + lower compression could also be a worn camshaft lobe. I think that engine has hydraulic lifters but you may be able to snug them up a bit. You can also sometimes clean them by adding a cup of automatic transmission fluid to the oil, then run the car hard and change the oil out.
Sep 06, 2007 (12:09 am)
so would a cam kit be a good idea right now or not. pull the heads and change everything out, valves and all. im going to try that trany oil thing u talked about. what it there is alot of carbon build up on the pistons and the heads. then what. clean it myself or take it in, cause yesterday me and my uncle bought a 63 chevy c10 and the heads looked like some one put mud on the pistons and alover the spark plugs. really bad. ok so my truck now, the idle is lower at around 600 to 500 rpm at idle and under load about the same just lower , man it run really good at night with that cold air coming in, is that how its supose to run during the day??? really ballsy with just regular gas from chevron. ive tested all other ones and chevron seems to last me longer and better performance out of it? Hey thank alot for helping me out. really do appriciate it> Ben.
#17 of 17 Hondas and lead
Sep 10, 2007 (7:41 am)
I had an 8o Accord and later an 85. Both were capable of running on leaded fuel in that they didn't have catalytic converters but the last year that Honda had a filler neck that would allow the leaded gas nozzle in was 1979.
I believe they changed the filler neck due to federal regulations kicking in. That's what the Honda service guy said - at the same time he was suggesting ways around it if I wanted to do that.