Chevy 366 hop up

[Gyva]

I'll call a few cam manufacturers first but it should be no problem going just under a 1/2 inch. the valves close before the piston starts coming back up. its just a matter of the head spring being beefy enough to close it quickly enough before the piston hits it, thus the double and triple coil head/valve springs you see on performance engines with way lifted cams...

[paul iossi]

Be careful with making major changes, power increase directly affects durability, (no free lunch). The next thing is to remember is that horsepower is just a number derived from a mathematical calculation(torque X rpm /5250) the torque is what does the work. An engine can only pump so much air CFM. displacement X RPM max / (12x12x12) 1 cubic ft. When you increase airflow through the engine you increase the rpm where the torque peaks raising hp but not necessarly torque. With that being said, if it was mine I would probably go with a mild increase in camlift and possibly duration, advancing the cam timing lowers the power band(higher ntorque @ lower rpm) warning make sure that you don't crash your valves and pistons. Then small diameter primary tube headers to keep exhaust velocity maximized,then thru a hi flow muffler and 3" mandrel bent pipes to the rear bumper-dual exhaust. Big truck parts house should have 10' sticks and mandrel bends of pipe-cut to fit and weld together. On the intake side cool air is also a good friend, plumb from the cowl area, you get less garbage in the intake from there than the grill. If you have a governor turn it up to engine redline, if you disable it you risk engine overspeed and the associated early demise of the engine. The stock HEI ignition is plenty hot enuff for a stock engine up to about 6000 rpm. Call some of the aftermarket cam mfg's and see what they recommend and then compare that to the factory cams, then make your choice. this engine does not tollerate high rpm and/or excessive valve lift vert well.
good luck

[Gyva]

I agree, I'll call a cam manufacture first that is familiar with the 366, not just big blocks in general...


Mike...

[hoser]

This is a 366, I forget the exact valve sizes but they are HUGE when compaired to what you find on a sb engine of the same cubic inches and the SB guys would lust after valves as big as those found on the "366" I know I wish I could put them in my sb 350 I seen what its like going from 1.94's to 2.02's dont try to compare this 366 valves, heads, ports with other bb engines like the 454, sb 400's punched out to 427 are running smaller valves and ports than my stock 366 is, dont hear anybody ragging on them, they make plenty of power..

I suggest taking the 366 like every other TRUE engine builder does on a case by case basis then design and engineer the specific engine for the specific application, forget about everything you ever read about BB Chevy engines and build and tune it for your BUS not your Nova or pickup truck, your pulling 2 nova's and a pickup truck all at once with your 366...

Just my .02

[paul iossi]

amen brother, its a tall deck truck engine, not a passenger or hyper bigblock-apples and grapefruit.

happy holidays

[hoser]

Any more thoughts or updates?

[sportyrick]

I think that .234 lift is at the cam, actual valve lift is a wopping .386. Like I said, if you put in too much cam duration then the intake valves can't sit on the seat long enough to keep cool and you will beat the valves out of round when they soften up. Also the ramps leading up to and off of the cam lobe are important in keeping the valves and seats in good working order, softer landings. I was looking at marine cams for my 427, they have to make power all the time like a bus, unlike a drag, circle, 4x4 which only has to make power for a short time. Come to think of it, solid lifter cams have quieting ramps built in. Helps me remember the old 68 Z-28s with the optional Zuntov solid lifter racing cam and 2X4 cross ram intakes. You could hear the rocker arms rattling a block away and those buggers were FAST. I'm pretty old to remember that. I think a boat guy is the one to talk to, not only do they have to make tremendous amounts of power they have to live a long life. I have gone tubing a couple of times this year and it still suprises me how much power a boat consumes. sportyrick

[paul iossi]

have you tried to adjust the ignition timing a couple of degrees when you change altitude? back in the 70's i had a neighbor that used to stop and change the timing on his dodge motorhome when he started to gain altitude in the rockies. their should be an old timer in the mountains that can tell you how much (degrees) and which direction advance or retard, sory but my memory just doesn't work that well anymore.

[hoser]

Originally Posted by paul iossi

have you tried to adjust the ignition timing a couple of degrees when you change altitude? back in the 70's i had a neighbor that used to stop and change the timing on his dodge motorhome when he started to gain altitude in the rockies. their should be an old timer in the mountains that can tell you how much (degrees) and which direction advance or retard, sory but my memory just doesn't work that well anymore.

Somewhere I seen a advance retard box you mount on the dash (or where ever) so you can adjust your timing on the fly.

The newer megasquirt allows you to play with timing too.

http://www.megasquirt.info/

[the_experience03]

MSD makes such a part (though you would need to be running their CD box as well)



Adjustable Timing Control,
PN 8680
The MSD Adjustable Timing Control puts you in control of your ignition timing - from the driver's seat! A dash mounted control knob allows you to adjust the ignition timing to compensate for changes in altitude, low octane gas, or heavy loads. For cars driven every day but raced occasionally on the weekends, this control is perfect. Increased fuel mileage and performance are just some of the benefits as the ignition timing can be advanced or retarded to prevent engine detonation.
The control knob mounts to the dash board for easy and accurate timing adjustments up to 15°. The Control can be used on 4, 6 and 8-cylinder engines and must be used with an MSD Ignition Control.

[Glide2277]

Hi
I am new to the site. I just bought a mini-pumper at auction with a 366. It turns over but does not start. I am hoping someone can tell me what types/brands of wires i can use to replace the wires that go from the distributor to the spark plugs...
also, general advice--it has been sitting for 2 years in New Mexico, where it is cold in the winter, and a lot of snow...any ideas about what is wrong, and how to get it running...i am trying to get it back to California, and basically burning money every day i stay here...anyway, as you can see i know almost nothing compared to the people on this site...but hope to learn more. thanks very much.
Glide

[the_experience03]

Suck, squish, bang, blow...that's what an engine needs to do to run and in order to do those things it needs fuel, air, spark, and compression. You can start by checking any one of those, but you need to figure out what's missing.

First and foremost, if you can tell us if it has a carb or is fuel injected that would help tremendously. Furthermore, if it has a carb we need to know if it is gasoline or propane.

Ok, I'm going to assume a few things here.
1. It has a carb
2. It uses gasoline
3. It cranks over sufficiently but will not start.

The very first thing I would do is a tune-up. This need not be terribly expensive and it should be done whether the ignition system is at fault or not. I happen to really like ACDelco wires, but Taylor wires are also decent. NGK's are probably my favorite, but are only available for import cars. The same is true of the spark plugs. I'd run either ACDelco or NGK (who happen to make most ACDelco plugs now). Replace the distributer cap and rotor as well as points and condenser if you don't have an electronic ignition.

Normally I'd call the ignition system into question which is why I think you should do that tune up anyway. Check and make sure you have spark when you're all done. You might have a bad pickup or module. A $2.99 spark tester is your friend. Make sure you have spark at the plug end of the wires. If not, make sure you have spark coming out of the coil. Just work your way back. I'd be happy to hepl you if you get it tracked back to no spark that far back.

The thing has been sitting for a long time and gas goes bad. I wouldn't be surprised if you have a gummed up carb, plugged up filter, or gas that just plain won't kaboom anymore. You might not even be getting gas to the carb from the pump. I'd start by spraying just a little carb cleaner, brake cleaner, starting fluid, etc down the throat of the carb. See if it pops. If it does, try pouring just a little fresh gas down the throat of the carb and see if the prime is enough to make it take off. I really think you should get that nasty old fuel out of the tank and start with fresh. At the least, dilute it with fresh gas and put some additive like BG 44K or Seafoam in it to help clean things up.

Does it sound like it even has compression when you turn it over? When you're replacing the spark plugs I'd pour about a tablespoon of transmission fluid down each spark plug hole to help establish a good ring seal and free things up.

[Kirbystud]

I have a 366 in my bus and it will run all day long at 3200 to 3500 RPMs at 65 mph. When going up a hill it will drop 5 mph or so....I have installed new daul exhaust 2 1/2 to the back tires. New carb I went with a Q Jet.... I would make sure all is work on your engine before changing out stuff......

[CAMO-MONSTER]

Originally Posted by westport_wayne

hoser, what is that 366 chev engine, a big block or a small block. its either a bored out small block or a industrial big block. my guess its a industrial big block. you could get a big block out of some earlier chev trucks or chevelles- cameros-ect. i had a old 78 chev 3/4 ton truck that had a 454 big block in it with headers and it had lots of power. if it is a big block, why wouldnt 454 parts fit on it ????? the older ones were 396-427 c.i. theres tons of parts for those things in JEGS and mags like that. that 366 might be just a detuned big block- i m not sure. some other gearheads on this site could probably tell you. just my 2 cents, john

There's more to it than that, but that's a good starting point. If you'd like to read up on heads a good starting point will be this site.

The 454 in my skoolie is I think out of about a 76 pickup or suburban. And yes the 366 is a industrial big block, with s#@ty heads and intake.

Go to Hastings and look at HOW TO HOT ROD BBC or any of the other BBC book's.

[spirit_of_76]

B&M supercharger for big block Chevy for sale salehttp://asheville.craigslist.org/pts/1603164996.html

[spirit_of_76]

try this http://asheville.craigslist.org/pts/1603164996.html

[cecilwlsn30]

You can get cams and other parts from jegs for the 366 AND 427 tall deck motors from online and most car quests can order bigger parts for them . People talk bad about them motors but I have one in my jimmy that I'm very happy with

[ElliottExpedition]

I just bought a 1987 Chevy Carpenter bus with a 366 in it. The former owner put dual exhaust on it to try and improve gas mileage and maybe power. I don't think it worked. On the 250 mile trip home it got about 5 mpg. That sucks! (pun intended). He suggested changing out the rear gearing to lower the rpms and get better gas mileage. However, I am wondering if this engine is just a gas hog or if both mileage and power can be improved? I have heard that it is a good engine as far as sturdiness goes.

[hoser]

Originally Posted by ElliottExpedition

I just bought a 1987 Chevy Carpenter bus with a 366 in it. The former owner put dual exhaust on it to try and improve gas mileage and maybe power. I don't think it worked. On the 250 mile trip home it got about 5 mpg. That sucks! (pun intended). He suggested changing out the rear gearing to lower the rpms and get better gas mileage. However, I am wondering if this engine is just a gas hog or if both mileage and power can be improved? I have heard that it is a good engine as far as sturdiness goes.

What elevation have you been running it at?

My bus with the 366 is long gone I switched out to a 22' class A RV with a 454 it gets 7.5mph towing my trailer loaded through the mountains and 10 mph on flat land and 1000' elevation and below.

[opus]

2 engines I was fond of, the 366 and the Ford 377. You like the 454 better than the 366?