6293 and a 8445 WTF!!!!!!

QUIP'6'

Brian Roman
Joined
Nov 26, 2003
after i ported my heads i noticed one is a 8445 and the other is a 6293 now the 6293 has one coolant passages in each corner and the 6293 has two one in the lower corners its not bridged is it ok to have an unbridged head or can you drill a hole in the head :eek:
 
Not sure what you mean. do you mean that the passage that leads to the intake manifold has a divider down the middle? If so, it should be fine. What I would be concerned with, is the possibility that you have different sized valves, different sized combustion chambers...something. Maybe not, but I would check all that out. You dont want one side of the engine to have more compression than the other.
I found this thread for you.....

http://www.turbobuick.com/forums/archive/index.php/t-69178.html

http://www.turbobuick.com/forums/showthread.php?s=&threadid=69444
 
no the coolant passage where the head and block meet there are one in each corner on the 6293 head there are only two at the top
 
lpaulabbott said:
after i ported my heads i noticed one is a 8445 and the other is a 6293 now the 6293 has one coolant passages in each corner and the 6293 has two one in the lower corners its not bridged is it ok to have an unbridged head or can you drill a hole in the head :eek:


I've read that the "bridged" heads are the more desirable as they are stronger.

HTH
 
VadersV6 said:
What I would be concerned with, is the possibility that you have different sized valves, different sized combustion chambers...something. Maybe not, but I would check all that out. You dont want one side of the engine to have more compression than the other.

Those two casting numbers have the same size valves and chambers. The big difference is in that bridged coolant passage and usually the 6293 has .552 diameter valve guides and the 8445 have .600 valve guides. Some 6293 are drilled for standard thread hardware(accessory mounting brackets) and some metric but the 8445 will always be drilled for metric.
 
i checked my valves and the stems all fit in each head the same no play so maybe its a certain year the guides have no inserts also do you guys put valve seals on exhaust to?
 
i checked my valves and the stems all fit in each head the same no play so maybe its a certain year the guides have no inserts also do you guys put valve seals on exhaust to?

about two years ago i bought a set of ported stock heads from champion--------one of them was 8445 and one was 6293--------at first i was concerned but after comparing them closely there didn't seem to be any meaningful difference---------i guess they don't see much difference either---------as for using seals (stock ones) on the exhausts i believe that the guides have to be machined for clearance-----------i had someone visit my shop about a year ago to build an engine----------he had his heads ported by someone with a good reputation according to lots of guys on the net---------i have a special breakin stand with harness/fuel lines where i do first startup and run-in before installation in a car------really makes it easier---------we noticed oil slowly dripping out of the exhaust------------at first it was really puzzling but after close examination it was clear what was happening---------the builder had put seals on the exhaust valves without machining the seats where they are supposed to fasten------the seals moved up and down with the valve and acted like a piston and forced oil into and down the stem--------since the oil never entered the combustion chamber it didn't smoke------if we had put that engine in a car we might not have noticed it but it no doubt would have had excessive oil consumption-----------i removed the seals on the exhaust valves and it stopped............RC
 
Top