[Formulajones]

There's core shift too that will affect whether you hit water or not.

I ran into that 30 years ago with BBC heads. You can do a dozen of those and be fine then have one set that an exhaust seat hits water.

It's not like it was a huge deal. The fix back then was to run some water through the engine first with some stuff that Moroso made at the time to seal the seat. After that, regular antifreeze mixture and you're good to go. I ran that engine hard for about a decade like that, no issues.

[Schurkey]

Corrosion from the water-jacket side is also a consideration.

[Jack Gifford]

One of the reasons for Pontiac's reverse-flow cooling ('55-'59) was to extend the service life of non-insert exhaust seats. [The second reason was for quicker warmup of bottom-end lubrication].

My pet peeve: almost universal reference to "hardened" seats. All of the steel seat insert blanks I've used were about 30-32 Rockwell-C, which is definitely not "hard".

[track73]

The seats on my #62 heads were beat down into the exhaust port from unleaded gas

[Jack Ferris]

Originally Posted by tom s

Kind of funny,a lot of people dont have the money to do things right but somehow find the money to do it over!Tom

This saying needs to go on my shop wall!!!!!!!! Brilliant!!!!!

[Half-Inch Stud]

Younz know that some springs (Single Spring, Dual Spring Sets, Damper purpose?) induce the valve to rotate, while others show ZERO rotation. Makes me wonder. Howbout you.

[Formulabruce]

Cool the seats... 421 mod, OR at minimum Drill the center hole between the block and head.
Why? Cool the exhaust valve area. Especially in the rear and middle two cylinders.
In the 70's they added EGR ( More heat) ran #45 plugs ( more heat ) ran 185 T stat ( More heat) and unleaded fuel, which allowed the heat to get crazy in the heads.
Today Alcohol adds more heat ( has more calories) and does less work.
44 max plugs, 170 max t stat, Fan Shroud ( real one) and the head/ block drilled and normal " street" driving will all be fine.
Of note... many get a " bung" welded into their exhaust to measure A/F ratio. Most Pontiacs with Q-jets will be too LEAN when trying to adjust to what folks feel is " Ideal" A/F. leaning out a Poncho just makes more....
HEAT... ..

[Schurkey]

Alcohol in the fuel adds more heat???

[Half-Inch Stud]

Younz know that the Auto Tech Training Manuals teach that EGR allows for a cooler charge.

Imaging thaat; Hot exhaust enables a cooler operation. Improved highway MPG anyway.

[SRR]

Originally Posted by Half-Inch Stud

Younz know that the Auto Tech Training Manuals teach that EGR allows for a cooler charge.

Imaging thaat; Hot exhaust enables a cooler operation. Improved highway MPG anyway.

It dilutes the oxygen. Less oxygen=less burn.

EGR brings down NOX levels for emissions.

[Ram Air IV Jack]

Originally Posted by Formulajones

I've had stock seats in mine for the last 25 years back when I built the engine. I tore it down about 5 years ago with over 70,000 miles and everything was perfect. I do run a pinch of 2 cycle oil in the gas for a little lubricity. Been doing that for going on 30 years now in various cars. Don't know if that contributes to longevity but it certainly doesn't hurt, but it does absolutely help to keep things clean. I'm not a fan of todays fuels but it's what we have.
Worth mentioning I've always had flat tappet cams in this engine and nothing more than 130 lbs. on the seat. Of course results will vary depending on several variables. Everything else here aside from the bug has hardened seats in it.

I have a dragracer friend of mine that said they use to run a bit of castor oil in their fuel for lubricant.

[Sirrotica]

Originally Posted by Jack Ferris

This saying needs to go on my shop wall!!!!!!!! Brilliant!!!!!

My father, a mechanic most of his adult life, as well as grew up on a farm, used to say it all the time. It's been around for awhile because I remember him saying it when I was a kid, I'm now 70....

He approached every task the same way, "Do it right the first time. or don't do it at all". Even though he grew up in depression era US, he always would spend the extra bit of money to make sure he didn't have to do the task over again.

Another saying he would say that is a similar take on the same subject, "There's never time to do it right the first time, but there's always time to do it over the second time".

Some of the gems I adopted to help me through my adult life.........

[Skip Fix]

Originally Posted by Ram Air IV Jack

I have a dragracer friend of mine that said they use to run a bit of castor oil in their fuel for lubricant.

My motocross buddies in high school used this in their 2 cycles!

If you ever do a 409 it evidently is real easy to hit water doing seats!

[Formulajones]

Originally Posted by Ram Air IV Jack

I have a dragracer friend of mine that said they use to run a bit of castor oil in their fuel for lubricant.

I imagine that would work well too.

I use a 2 cycle oil with TCW3 so it has some cleaning properties as well as lubricating the top of the engine.

[Formulajones]

Originally Posted by Skip Fix

If you ever do a 409 it evidently is real easy to hit water doing seats!

Yeah quite a few engines are susceptible. Like I mentioned I've had it happen on a BBC head. It's not the end of the world. Ran that moroso sealant through it as a precaution and it was never an issue. I even overheated that engine once when it threw the fan belt on a drag strip pass. That thing ran for years.

[Sirrotica]

Castor oil isn't really a solution to any 4 cycle engine in the crankcase. Early dirt track racers used it as it is a high quality oil before it's heated. After being heated in an engine it must be drained immediately before it solidifies into a molasses like semi solid.

It may be fine as top end oil, but knowing how it acts to thermal cycles I would be leery of it sticking rings.

The Biggest Disadvantages

Castor motor oil is well known for leaving large “gunk” deposits behind on engine parts.
In premium fuel, castor oil may separate from the fuel in low temperatures.
Oil injection systems and castor oil don’t mix (pun intended).

[Formulabruce]

Originally Posted by Schurkey

Alcohol in the fuel adds more heat???

YES! , of course!
Alcohol has MORE calories and higher Octane than regular gasoline.
That said, because its Less dense, the engine must work harder to do the same work. A new truck EPA mileage sticker tells the story. Cruising range on 10% ethanol gasoline, vs E-85 , which is about a third less.. Much Less fuel economy.
A engine working harder makes more heat.

[Formulabruce]

Originally Posted by Half-Inch Stud

Younz know that the Auto Tech Training Manuals teach that EGR allows for a cooler charge.

Imaging thaat; Hot exhaust enables a cooler operation. Improved highway MPG anyway.

In Theory that's true, starving the O2. In reality though, the higher temp T-stats, hotter plugs, and leaner and Locked carb Idle adjustments made a hotter environment under the hood.

[Half-Inch Stud]

As for EGR for our hobby; i've schemed ways to implement a variable EGR into my engine for the benefit of running 87 Octane for MPG, and ability to accelerate hard.

Best result has been the exhaust design, a big cam overlap, running pig-rich carb settings that run the engine properly, and some luck.

I think a driver-seat adjustable method using the exhaust crossover and any favorite intake manifold is possible but I never got there. Factory method doesn't grab me.

[AG]

Originally Posted by Formulabruce

YES! , of course!
Alcohol has MORE calories and higher Octane than regular gasoline.
That said, because its Less dense, the engine must work harder to do the same work. A new truck EPA mileage sticker tells the story. Cruising range on 10% ethanol gasoline, vs E-85 , which is about a third less.. Much Less fuel economy.
A engine working harder makes more heat.

Not sure about this, the heat of combustion for gasoline is 20,400 BTU/lb and ethanol is 12,800 BTU/lb.