NewbVetteGuy

Starting this thread to answer two different questions:

1. If I take all the brand new valves out of my heads should I ensure that I put them back into the same chamber, or does it not matter which one they go back into?


2. What's involved in removing valve guides and putting them back in? Do I need special tools? What's the risk of damaging them when removing them and reinstalling them? (If I decide to get the chambers coated everything's got to be removed.)



Adam

calwldlife

if they are all new then they should be the same and no issues with matching guides.
if it gets to the point that stems are worn or guides
the usual procedure is change the worn part.

pulling guides is a pain.
putting in guides is a pain. heat heads and cool guides type
deal.

best left to a shop.
did they check worn?

REELAV8R

Eccentricity is very important to the valve seating properly. That is established with the valve guides.
If you pull them they’ll have to be checked or the eccentricity re-established.

What coating you talking about.

Easy Mike

IMHO: pass on getting the chambers coated.

REELAV8R

Seems like it could be problematic in the future if the coating isn't applied correctly, starts flaking off, or gets compromised somehow then you got a problem that may be bigger than the benefit it's offering.

PainfullySlow

Coatings on pistons and cylinders has been in use in high performance engines for decades, I highly doubt that there is a serious cause for concern.


Now, I do agree with you that it is entirely not worth it for a street engine and especially with our relatively sloppy fit small block chevys. Add the fact that you would have to take the heads to a shop to have the guides properly installed this really isn't worth it IMHO.

NewbVetteGuy

I have a "max effort" torque and MPG build and my thinking was that 10-15 ft lbs across the RPM range and 1/2 to 1 mpg improvement would go nicely with my build and if i'm taking out everything except for the valve guides anyway, I should at least consider it.

I would go with zirconia thermal barrier or nothing; (Swaintech).


Sounds like removing the valve guides and installing them is a huge PITA and no way I want to get into that so the coatings are officially OUT.


I'm abandoning chamber coatings.


Adam

NewbVetteGuy

"Worth it" is pretty subjective and varies by person.

Let's talk about what you stand to gain; the costs are well known then people can make an informed decision.


Note: Not all thermal barrier coatings nor the companies doing the application are created equal.


http://swaintech.com/what-to-expect-...ing-my-engine/

At 6,000 ish RPM you're going to get near enough to zero gain from anything except the thermal barriers.


For some reason I remember the test below being on a 305 Chevy, but I can't find that reference anywhere now. This is with the chambers and the piston tops coated.

With no modifications other than the coatings, the dyno pulls clearly showed the torque and horsepower curves were much better. Both curves were fatter in the lower rpm ranges where it will improve the drive off corners, and both curves were flatter as well. Peak horsepower was up 2% from 318 to 324 horsepower and peak torque was up 5% from 320 lb/ft to 335 lb/ft. In the heart of the curves, these numbers were even more impressive. At 4,500 rpm, torque was up 7% from 298 lb/ft to 319 lb/ft. At 5,500 rpm, horsepower was up 6% from 302 to 320 horsepower. Most engine builders will take full advantage of the coating by making jetting (or computer), timing, and lighter weight oil for maximum power gains. However for this test, we wanted to document and publish the gains that are achieved if the only modification was coating the engine. If the proper tuning adjustments were made to take full advantage of the coatings, these results would have been even more impressive.



Adam

REELAV8R

I don't consider how long something has been in use as an accurate gauge to it's success.

Ceramic coatings for exhaust components has been around for decades as well yet somehow companies find a way to apply it incorrectly or poorly resulting in poor longevity or results.

The same could be said for pre-assembled heads, somehow places like Jegs find a way to do it wrong. Had Adam not taken the time to check things out his heads/ valve train would have not lasted long under valve springs with no locators.

So unless this is a race effort, then I would not agree with coating it.

On a street engine you want to build it and run it. Not have to disassemble it regularly to check or repair things.

domenic tallarita

I agree with the eccentricity factor. NO way would you not have to grind the heads after removing the guides! You would have a better chance of winning the lottery than the valves seating properly.

Dom