Valve size questions

[fuzzyGN]

I was wondering if the valve seats need to be replaced if "big" valves are put into 87 heads. I don't think the increase in valve size is all that much but not sure if a healthy seat can be machined that much without problems. Anyone have any real world experience? Thanks

 

[UNGN]

A machine shop charged me $60 to machine a pair of heads for 1.77 Valves.

 

[Nick Micale]

New seats are not required for 1.77" valves.

 

[TIMINATOR]

If you don't have the chamber wall opened up, in many cases you will net less flow with a larger valve. I would prefer to see you unshroud the valves and do a better valvejob with throat, front, and back cuts and/or pocket porting. IMHO that's a better way to go, but then again, I live on my flowbench.
If you flow the port, and then reflow it with the bigger valve, it will show how much you will lose to shrouding. Then have someone that knows Buick heads give you a pro opinion. Or just talk to a Buick head porter first.
The #1 mistake most make is in assuming the port stops at the valve seat. If you treat the chamber as an important part of the flow path you are ahead of the game.
P.S. you did have the intake manifold ported, and entire EGR setup in the plenum removed first didn't you?
TIMINATOR

 

[Chuck Leeper]

Hey Tim, a bit late on this one.... 2004!

 

[TIMINATOR]

Either my computer or this website! Sometimes it loads with current threads, sometimes with whatever....
My bad for not checking!
Mine shows it as a post from this week!
I will have to pay more attention!
TIMINATOR

 

[dynoman]

Mine shows it as a post from this week!

I have noticed this , happened to me ...... only I didn't respond to the post . That last system recovery screwed up a few things .

 

[Mr.Spool]

Hey Tim, a bit late on this one.... 2004!

 

[Mr.Spool]

If you don't have the chamber wall opened up, in many cases you will net less flow with a larger valve. I would prefer to see you unshroud the valves and do a better valvejob with throat, front, and back cuts and/or pocket porting. IMHO that's a better way to go, but then again, I live on my flowbench.
If you flow the port, and then reflow it with the bigger valve, it will show how much you will lose to shrouding. Then have someone that knows Buick heads give you a pro opinion. Or just talk to a Buick head porter first.
The #1 mistake most make is in assuming the port stops at the valve seat. If you treat the chamber as an important part of the flow path you are ahead of the game.
P.S. you did have the intake manifold ported, and entire EGR setup in the plenum removed first didn't you?
TIMINATOR

Better late than never buddy

 

[Mr.Spool]

If you don't have the chamber wall opened up, in many cases you will net less flow with a larger valve. I would prefer to see you unshroud the valves and do a better valvejob with throat, front, and back cuts and/or pocket porting. IMHO that's a better way to go, but then again, I live on my flowbench.
If you flow the port, and then reflow it with the bigger valve, it will show how much you will lose to shrouding. Then have someone that knows Buick heads give you a pro opinion. Or just talk to a Buick head porter first.
The #1 mistake most make is in assuming the port stops at the valve seat. If you treat the chamber as an important part of the flow path you are ahead of the game.
P.S. you did have the intake manifold ported, and entire EGR setup in the plenum removed first didn't you?
TIMINATOR

But it is a great post

 

[1986 Buick GX1]

Can’t blame a guy for wanting to help.
I learned something, so it wasn’t for naught.

 

[TIMINATOR]

Thanks guys!
Been having a pissy few weeks, I appreciate the words!
4 incorrect p/s hoses!
Alternator rebuilder lost the pulley!
One of my workers lost the box full of bolts and rear coil support!
Had Obama rigged t stat retainer, and cam sensor hold down. Now handled.
Back to the 500 piece puzzle without the picture on the lid...

TIMINATOR

 

[dynoman]

It only took 19 years to get an intelligent response on what needs to be done along with the install of larger valves .

 

[TIMINATOR]

I'm working on posts for 2042 right now!
Pic of 500 piece puzzle as of 10:00 last night.
Gonna do wires,, small details, and prelube today, get it in the car over the weekend, then do the 70 mm TB, and my custom inlet/air cleaner piping. The A/C compressor is due in Friday.
TIMINATOR

 

[Reggie West]

Remflex has the gasket from turbo to downpipe.

 

[TIMINATOR]

T/A Perf. said no gasket.