Stock valve sizes?

[87we410877]

What are the sizes of the stock valves on an 87? Mine are 1.775 and 1.498. I did a search and for some reason the page doesnt load when i type in valve size/stock valves. Weird. Thanks.

 

[Zurn]

valve size

I think that is right, 1.77 and 1.50 are the stock size. Somebody will jump in if I'm wrong.

 

[87we410877]

I think that is right, 1.77 and 1.50 are the stock size. Somebody will jump in if I'm wrong.

I'll be amazed if they are stock. I was told the heads had bigger valves.

 

[frankg]

1.71" and 1.5" are stock you have bigger intakes at 1.77" Frank

 

[87we410877]

1.71" and 1.5" are stock you have bigger intakes at 1.77" Frank

Thats not good. The chanpion Irons come with 1.900" intake and 1.600" exhaust . At least thats what the GN1's have. Doesnt list the Irons valve sizes. I wish they were more informative about their products. Are thoes valve sizes good sizes to buid a low 10 consistant motor?

 

[bison]

Thats not good. The chanpion Irons come with 1.900" intake and 1.600" exhaust . At least thats what the GN1's have. Doesnt list the Irons valve sizes. I wish they were more informative about their products. Are thoes valve sizes good sizes to buid a low 10 consistant motor?

No. Im almost positive champions come with 1.77in, 1.5ex and flow much more than the stock irons, especially on the exhaust side. You cant put the same size valves in the irons as the GN1's. The locations are too close together. Ive got 1.77in, 1.5ex in my irons and they almost touch. Moving the valves outward would be costly and not flow good on a 3.8 bore. the valve spacing must be different on the GN1's. There was a pair of maxed out irons in the parts for sale section that flowed nearly as much as a set of GN1's . Unless you have a really strong bottom end you wont be able to really take advantage of a heavily reworked set of aluminum heads on a weak production block. I would look at the bowl work to see if the heads are worth playing with. Just putting in bigger intake valves wont do much for performance. The exhaust is the real bottleneck on these. There are plenty of iron headed cars going 130mph+ traps in full weight cars.

 

[87we410877]

No. Im almost positive champions come with 1.77in, 1.5ex and flow much more than the stock irons, especially on the exhaust side. You cant put the same size valves in the irons as the GN1's. The locations are too close together. Ive got 1.77in, 1.5ex in my irons and they almost touch. Moving the valves outward would be costly and not flow good on a 3.8 bore. the valve spacing must be different on the GN1's. There was a pair of maxed out irons in the parts for sale section that flowed nearly as much as a set of GN1's . Unless you have a really strong bottom end you wont be able to really take advantage of a heavily reworked set of aluminum heads on a weak production block. I would look at the bowl work to see if the heads are worth playing with. Just putting in bigger intake valves wont do much for performance. The exhaust is the real bottleneck on these. There are plenty of iron headed cars going 130mph+ traps in full weight cars.

My bottom end consists of Eagle crank, K1 rods, Diamond pistons, RJC Grudle, 4 Billit Caps, and its .030" over. Im looking to go very low 10's with possible 9's in the future. Should i just pony up and get the Champion Irons? Or work with my stock irons? The champion head plant is about 5 minutes from my friends house. Im going to go check them out. What do you guys think i should do?

 

[bison]

My bottom end consists of Eagle crank, K1 rods, Diamond pistons, RJC Grudle, 4 Billit Caps, and its .030" over. Im looking to go very low 10's with possible 9's in the future. Should i just pony up and get the Champion Irons? Or work with my stock irons? The champion head plant is about 5 minutes from my friends house. Im going to go check them out. What do you guys think i should do?

Id go for the proven head. There around $1200, and its a no brainer head change. Bring them to champion and ask for their opinion.

 

[87we410877]

Id go for the proven head. There around $1200, and its a no brainer head change. Bring them to champion and ask for their opinion.

By proven do you meen the Iron Champs? In that case thats what i was thinking. I'll be visiting their facility in 2 weeks. I'll bring my heads. Hey maybe they will take em.

 

[bison]

By proven do you meen the Iron Champs? In that case thats what i was thinking. I'll be visiting their facility in 2 weeks. I'll bring my heads. Hey maybe they will take em.

Yes. I have seen some really good work come from there. Weber has some nice ones too. There are a lot of others but those i stated are proven performers.

 

[87we410877]

Yes. I have seen some really good work come from there. Weber has some nice ones too. There are a lot of others but those i stated are proven performers.

Awesome. Thankyou for the info.

 

[Nick Micale]

Thats not good. The chanpion Irons come with 1.900" intake and 1.600" exhaust . At least thats what the GN1's have.........?

The GN-1 heads have the larger size valves because the guide bosses have been moved apart to accomodate then.

The 1.77"/1.50" valves are as large as will fit in a stock iron head.

This is why the aftermarket alum heads will outflow a worked, stock iron head, no matter what you do to them.

 

[87we410877]

The GN-1 heads have the larger size valves because the guide bosses have been moved apart to accomodate then.

The 1.77"/1.50" valves are as large as will fit in a stock iron head.

This is why the aftermarket alum heads will outflow a worked, stock iron head, no matter what you do to them.

So that explains it. Thanks alot.