[swompz]

Had a friend stop buy the shop today armed with a pair of cylinder heads hes aquired,

there alloy 2.2/ 1.60 valve sizes but have no distinguishing features, wandered if pro comps or blue print??

[F-BIRD'88]

Post a clear pic of the exhaust port face of the head.

Possible PBM "Lightning" head. Or non Brand name labeled no name derivitive. Lots of these floating around. Similar to a older ProComp.
Best to check all machining valve guide clearanceing
and valve job seat concentric and location.
(see if the valve seal on the seats)

Kinda rough as cast ports but can be improved with porting.
They have potential (with work) but out of the box is likely only fair.

usually these are sold cheap on Ebay etc.
ya get what you pay for.
Suspect alloy and heat treat etc. "chinesium"
What is the intake port volume?
The ones I seen were 190cc
Was not impressed. Even for the cheap price offered.

There is lots of pretty good "cheap" stuff now.

[begtadiffer]

Thats all I wanted to say!

[swompz]

Originally Posted by begtadiffer

Thats all I wanted to say!

Cheers lads I'll let him know.

[engineczar]

They definitely look like PBM's. The coolant passages are identical. Big intake valve on that baby.

[swompz]

Ok, does anyone know how I can work out what length valves he needs?

[engineczar]

They appear to be a standard 23 degree head so a small block Chevy valve length will work unless you're looking at throwing a lot of lift at it then you could go +.100. Do you have a cam yet?

[swompz]

Originally Posted by engineczar

They appear to be a standard 23 degree head so a small block Chevy valve length will work unless you're looking at throwing a lot of lift at it then you could go +.100. Do you have a cam yet?

I thought the valves on these engines came in different lengths? I was looking at manley valves which were 491 & 510 & the +100 options

surely there length could effect the installed spring heights & possible rocker geometry ?

[swompz]

Originally Posted by F-BIRD'88

Post a clear pic of the exhaust port face of the head.

Possible PBM "Lightning" head. Or non Brand name labeled no name derivitive. Lots of these floating around. Similar to a older ProComp.
Best to check all machining valve guide clearanceing
and valve job seat concentric and location.
(see if the valve seal on the seats)

Kinda rough as cast ports but can be improved with porting.
They have potential (with work) but out of the box is likely only fair.

usually these are sold cheap on Ebay etc.
ya get what you pay for.
Suspect alloy and heat treat etc. "chinesium"
What is the intake port volume?
The ones I seen were 190cc
Was not impressed. Even for the cheap price offered.

There is lots of pretty good "cheap" stuff now.

gave him a call & hes guna try drop em off to me on monday so will take a couple more shots then

[F-BIRD'88]

More radical hot street/strip to race:

Usually if going with .550" lift or more I go for the +.100" valves as the larger diameter dual valve springs used, want this. 1.80" +/- ish installed height.

Most street perf hyd flat tappets and moderate street-strip solids:

If you will be using stock diameter hi perf springs 1.25" +/- and modest .530" or less valve lift (typical 1.70 to 1.75" installed height) a standard stock length valve gets it done.

What cam is being used? what max rpm?

[swompz]

Originally Posted by F-BIRD'88

More radical hot street/strip to race:

Usually if going with .550" lift or more I go for the +.100" valves as the larger diameter dual valve springs used, want this. 1.80" +/- ish installed height.

Most street perf hyd flat tappets and moderate street-strip solids:

If you will be using stock diameter hi perf springs 1.25" +/- and modest .530" or less valve lift (typical 1.70 to 1.75" installed height) a standard stock length valve gets it done.

What cam is being used? what max rpm?

well matey dropped heads offto me today, so will post more pics later on. having had a chat about what he's doing with them it looks like ive possibly struck a deal with him for them, so ....
the cam in my motor is a sum-1102 , but having talked over options in another thread I may look at the 1103 or 1788 cam for my build if I fit these.
max rpm 5- 5.5k
while im thinking about it as anyone used the sum-1788 cam?

[swompz]

as promiced a couple more shots of said heads.