LS1 springs

[bszopi]

Anything with a 3.1 from about 88/89 to 93.

[v6h.o.]

ahem.... up to 94 (jbodies)

[RidgeRunner]

ahem.... up to 94 (jbodies)

And Lumina

[AaronGTR]

Ok, I'm having a problem with the heads project. The crane rockers are ordered and I have all the guide plates I need now. I have the LS1 valve springs and everything else I need. Problem is the valve seals. I got a 3.1 "T" valve seal and I don't like the way it fits. The valve stem fits perfectly but it doesn't fit over the valve guide very well. You really have to force it down and I'm concerned that will make the part around the stem deform and leak when the engine heats up. I also tried a valve seal from GM performance parts for a ZZ4 V8. It fits the valve guide perfectly and it fits the valve stem but not as tight as the other one. I'm pretty sure the V8 valve stem is bigger, and again concerned that valve seal would leak when the engine's hot. The 3400 valve stems are 5/16" diameter, so I would assume the V8 is 11/32" (that's pretty standard).

What I need to know is, what size are the V8 valve stems, did the 3.1 "T" use more than one size valve seal, and does anyone know of a seal from another engine that would work?

I'm going to try LS1 seal and a few others, but I figured I might ask you guys too.

[mfuller]

Most of the Gen III and newer engines have 8mm valve stems, per GM's service manuals.

[v6h.o.]

the 3.1L seals are tight even on the 3.1L engines. they do fit. i've used them for years with no issues.

[2_8_mpfi_chevette]

[quote="GPXSS"]

2. the weight savings isnt all that drastic over the stock retainer.. you get more of a savings by going to SI valves.



In hind sight.. im betting if you use Ti retainers, Ti locks, and Si or other lightweight valves, you can run stock 3100 springs on a high lift cam with no problems N/A.

What are Si valves?

[RidgeRunner]

Valves made by a company called SI Valves.

http://sivalves.com/

[2_8_mpfi_chevette]

That makes sence, thanks, sorry for the question but i had never heard of them before.
They only list valves for the 2.8. will these work with gen3 heads off a 96 3100.

[v6h.o.]

That makes sence, thanks, sorry for the question but i had never heard of them before.
They only list valves for the 2.8. will these work with gen3 heads off a 96 3100.

3100's yes.

[AaronGTR]

Do they make any valves that would work on 3400 heads?

[v6h.o.]

Aaron, the exhaust valves would. but the intakes wont due to as we all know the intake valves on the 3400 are a larger diameter valve compared to the set they make for the older 2.8/3.1L.

3400 intake valves would have to be custom made. which is not that hard to get done, just costs a bit more $$.

[mfuller]

Slightly off-topic.....I know most look to SI Valves for replacement valves. What's the word on Federal Mogul/Sealed Power valves (and lifters)? Are they just stock replacements (any better than OEM)?

[AaronGTR]

Aaron, the exhaust valves would. but the intakes wont due to as we all know the intake valves on the 3400 are a larger diameter valve compared to the set they make for the older 2.8/3.1L.

3400 intake valves would have to be custom made. which is not that hard to get done, just costs a bit more $$.

Hhmmm, so the exhaust valve for the 2.8/3.1 would work in a 3400 head. They are the same length and have the same diameter stem (8mm) right? Anyone know the length of the intake valve stem?

Wish I'd known about this sooner. I'm putting my heads on the car this week, so no time to get valves. Not that I really need them though, just would be nice. At least if I want them in the future I know where to go.

[RacerX11]

The 3.1/2.8 valves are slightly different. The retainer lock groove in the valve stem is a little closer to the end of the valve on the 3X00 (maybe 0.080" or so). This will affect spring installed height. You would have to play around with mixing and matching valves, retainers, and locks to get everything right.

Marty