Problem with Durabond Metal Seats

[ProPower engines]

SBI has the 2N seats for LPG fuels that work very well and easy to cut. Very high nickel content so they will last a long time.
Similar to a 7000 series Durabond seat but easier to cut. Not always made for every size OD/ID and depth. Custom seat requirements can be solved with the Durabond hockey pucks with a small center hole. I prefer them for radiused seats that way the bottom can blend to the bowl better without hitting the bowl with the bottom of the cutter blade.

[wyrmrider]

SBI 2n powered?
by 2n do you mean similar to 2n valves?
most likely would not work in pollution control application but may be ok for propane
thanks for the lead

[ProPower engines]

SBI 2n powered?
by 2n do you mean similar to 2n valves?
most likely would not work in pollution control application but may be ok for propane
thanks for the lead

I have used the 2N seats for both LPG and unleaded fuel with the same long lasting results.
I am not sure about the manufacturing differences between the SBI and Durabond seats but the 7000 and 9000 series Durabond and the 2N SBI seats seem to cut the same and both finish extremely well without the need to touch with a stone when sharp cutters are used.

[modok]

SBI seats:
normal hard seats= J-loy brand, cast "high chrome"
I think PEP's high chrome are a bit harder, but both very good.

N=nonmagnetic cast,
Has enough nickel and chrome to be nonmagnetic, is probably more than 2% nickel, as I'd expect that to be weakly magnetic, tho I could be wrong

P=powdered metal

These heavy duty cast seats, I never have problems with surface finish, but the force required to do a wide cut is so high you'll get deflection/chatter if taking a BIG cut, even using serti100. Nay need to shape them in a few steps, if there is a lot to come out.

[jcisworthy]

Excerpt from the SBI catalog

[ProPower engines]

The star "N" series SBI and the 9000 series are the same quality for long lasting seats in severe duty applications.
Even in std street stuff and mild to medium performance stuff they will out last the other sets 20 to1.
The 7ooo series Durbond are the equivalent to factory installed seats in heads such as GM Vortec and Dodge Magnum.

Cost for most guys is the big issue when buying seats especially in box quantities of 12 or more
Cheaper brands of seats I have seen are not worth the loss of durability

[modok]

I don't agree.
N series seats are stainless; massive amounts of chrome
Like nichrome wire, like 440 stainless
the 90000 series have only a few % chrome, in fact they contain more % nothing than % chrome, it's powdered cobalt drill material.
what is to prevent durabond seats from corroding? I don't know! Can you make toaster wire out of it? I don't think so. It's hard, but hardness is not the problem is a 22r. We don't know what the problem is, but it isn't hot hardness! It's got weak springs, turns slow, and runs relatively cool.

[wyrmrider]

for propane and natural gas star series and well tite (nickel based not just high nickel) were the standards for years 7000 series also
9000 series is better and the only thing I have found that will work in harsh dirty fuel environments
thanks for chiming in modok

[ProPower engines]

The 22R engines seem to run very high cylinder temps which is evident from the constant head gasket issues they see. The replacement heads today differ greatly from the original factory heads with the coolant passage beside the fire ring being less structurally supportive to the fire ring. It seems they run very lean in the fuel department which in turns causes the head to anneal in that area thus head gasket issues.

I have seen the seat wear issues they have had for years but again I have been using the N seat as they are intended to be run in high temp situations such as LPG fuels. There is a company here that has use those engines in wood chippers for years and they were both gas then later on LPG fueled but I continued to use the same seats without issues.
They all used light valve springs packages but a bit heavier then stock but I did increase the installed pressures on the exhaust to help with heat transfer its been fine ever since and the exhaust/intake seat erosion was eliminated.

I may also ad I also used special ordered inconel exhaust valves as the OE valves did not stand up to the LPG fuels.

What is different with the 22R stuff you have been doing that the seats/valves disappear quickly

[modok]

I agree they do seem to be tuned lean.
It's amazing the difference the fuel and tune can make. I've seen thousands of cummins b and c diesels, and seems like they have it RIGHT, as seat wear is usually the least of problems, but then started getting same engines in natural gas pump applications, and the seats would be worn, in some cases, all the way through.
Fitted seats recommended by Tucker, and now those are coming back, seats are only halfway worn though, which is good enough, considering the state of the guides.

[CREngines]

good thread here.

I have a 6.7 cummins head here i need to put some improved seats in that will deal with being over heated. was looking at the 90000 durabond or sbi N. Any other recommendations for extreme heat in a diesel?

[wyrmrider]

go with the durabond read and follow the cutting suggestions including those in this thread
good pilots, good tools, good guides

[modok]

I'd rather have stainless exhaust seats. If you get a loose exhaust seat in an detroit, or cummins, it is often the seat shrunk, and the hole is ok, it gets so hot it shrinks, although I doubt you will see that with the 4 valve, but the two valve ones will for sure. SBI lists and N seat, and I just happen to agree.

with cummins and int diesel, 4 valve heads, high EGT seems to me I we see more trouble with guides, stock or SBI seats do fine.
Used to use k-lines but no more, now extra hard guides, I think from SBI? Not sure. My home catalog is outdated, and so am I, I haven't done heads in five years(my job is now boring, lots of boring ), but I can ask my co-worker what those guides are if you need.

[ProPower engines]

SBI does have the best selection of hardened guides for many applications

[ProPower engines]

So are we talking about the valve stem and guide sticking?
That's a clearance issue and deposits from combustion and heat. How come its the seat being blamed?

We got a bit off topic with guides