on a 1.7 or 1.8 on the #3 cylinder to cool things down ?

No! It wouldn't be "politically correct" increasing your gas consumption to improve global warming......

It does not run hotter because it runs more lean, it runs hotter because it does not get it's fair share of airflow.


I would not recommend it.

Jim, do you read plugs? Put a colder plug in #3 and read them and make #3 look like the rest. The colder you go the closer to flowing the plug you'll get. So thats all you can damage.

I had the same issue along with every other type IV and i took a file and cleaned up all the extra flashing in between the fins on the head and all the holes that air is suppose to travel through and would not b/c of the extra flashing from when they make the heads, then i cut a 1/2 to 1 inch of the bottom of the tin that wraps around the back of the head closest to the back of the car so the air would travel by it easier i even opened the fins up al-little more. now both of my back cyl run equal and it came down almost 40 to 50 degrees because of that.

glad to help out : )

Please tell me you have a few pics of this?

Rich

mike

not without crawling under the car and taking some picts which I will try later this week it will only show the bottom and the tin i cut back to let more air flow over the head. but when i did it years ago i was amazed how much flashing was there. in between the spark plugs there were channels for the air to flow through and they were practical fully closed so air was only travelling on the outside of the cyl heads nothing in between them you will have to take the tin and manifold off to see it and file away to open them up.

here are some pictures of cyl 3 and sorry for the out of focus on showing the middles of the two cylinders but you get the idea on what to clean out on the heads. the 1st two pictures shows where i cut the tin back and the 2nd shows the center location

The hotter a cylinder runs the more it will appear to be lean... #3 will appear to run leaner as well with most exhaust systems due to the bend radius and length of it's primary.

Adding a larger injector to overcome the insdequacies of the stock cooling system would effect the engine in a worse way, by effecting exhaust gas temps and combustion balance.

The tangential flow of the clockwise turning fan and the cooling system characteristics create the crippled #3 cylinder that generally runs 50-75F hotter than the other 3 cylinders...

A lot of the temperature can be controlled with ba proper exhaust system- but no one EVER listens to that.

BTW- Finster, please move those oil hoses, they are soaking up all the heat from the heads and exhaust and putting that straight into the oil..

So, aside from a basic cleaning to get all the oil and dirt out, you actually removed metal from the fins?

Did you basically approach it like polishing each fin the get better air flow?
And you removed a portion of the bottom tin, or is that the rear piece??

Rich

That was one of my concerns and it was go short like that or longer to stay away but when i did it i watched the oil temp and it never goes above 220 even on the hottest days so i figured a longer run would be worse and if anything it helped get the oil to temp quicker and the head temp did not seem to be affected by it either b/c that runs at 325 to 375 max and max is running at 95 to 100mph. I have a seperate oil cooler with a Earls sandwich oil thermostat that works i think better than most b/c it stays fully closed until 180 then sends 100percent of the oil to the coolerwhen it opens when i looked at others they seem to mix the oil and it took alot longer to get to temp like the one Pelican parts sells do you know which one im speaking of it doesnt seperate the hot and cold oil it seemed to dilute it more or less to the oil cooler. while cyl 3 is better it still runs at most 50 degrees hotter than the front and about 30 degrees hotter than the other back cyl but it is not as bad as it was.

Mixing the oil is a must because it allows the oil that is in the cooler to warm up a tad before being dumped to the bearings when the T stat opens.. Doing this also allows the air to be bled from the system a bit at a time instead of all at once.

If you reroute those lines you'll lose a few degrees of temp and while the engine isn't getting hot now, @ 220F, it would if you hit the track that way and saw HI RPM for a while.

Removing the casting flash around fins is a good way of making the engine run a tad cooler by removing obsyructions in the fins and exposing more of the fin to the charge of air. I do this on our race engine, but have never needed to do the practice on a street engine.

Another way to drop head temps is to go with a different cam...

Another way to get a cool running engine is to go with a Jake Raby engine.