Captain Bondo Posted June 29, 2009 Report Share Posted June 29, 2009 I've heard that around 2000 or so, Volvo changed the coolant passages in the cylinder heads. Anyone have a comparison pic? I have also heard you can modify the earlier heads to be more like the later ones- I assume this revision improves flow priority to the chambers? '99 an '00 T6 headgaskets have completely different part numbers. Pretty weird. Any thoughts? Cheers! Link to comment Share on other sites More sharing options...
BlackT5 Posted June 29, 2009 Report Share Posted June 29, 2009 Check V@d1s? Link to comment Share on other sites More sharing options...
Johann Posted June 29, 2009 Report Share Posted June 29, 2009 Link to comment Share on other sites More sharing options...
BlackT5 Posted June 29, 2009 Report Share Posted June 29, 2009 Thanks Johann, I was hoping you would see this. That is the reason I didn't use the "S60R" headgasket. I wasn't sure how coolant flow would be affected, although several members seem to be running them without issue. Link to comment Share on other sites More sharing options...
lookforjoe Posted June 30, 2009 Report Share Posted June 30, 2009 How is the '00 head an improvement? It only has one central port on the exhaust side... Link to comment Share on other sites More sharing options...
socal850tuner Posted June 30, 2009 Report Share Posted June 30, 2009 How is the '00 head an improvement? It only has one central port on the exhaust side... Agreed... it won't make a difference. Link to comment Share on other sites More sharing options...
Captain Bondo Posted June 30, 2009 Author Report Share Posted June 30, 2009 Interesting- thanks Johann! I would be slow to write the change off as insignificant. Maybe. Seems like a lot of effort to go through for no functional change though... Volvo changed the cooling passages in the redblock motors in the mid 80's to smaller passages - the primary difference is that the heads are quite a bit stiffer - could be the case here but I doubt it, these heads don't have stiffness issues form what I've ever seen, and the modification is only on the exhaust side... Johann are the water passages inside the head much different from what you can tell? I guess it's hard to see in there... Coolant flow to the exhaust side of the combustion chamber is like, the single most critical point in the cooling system - so although it seems like an innocent change, I bet there is something to it. Maybe not critical, but coolinging that area can have a significant impact on detonation resistance. We need to get 2 junk heads and push them through the bandsaw. EDIT: Although, knowing volvo, maybe they decided that would heat the chamber up faster and improve cold start/warmup emissions and it's actually worse for performance. LOL. That would be pretty par for the course come to think of it. :lol: Link to comment Share on other sites More sharing options...
EricF Posted June 30, 2009 Report Share Posted June 30, 2009 Although, knowing volvo, maybe they decided that would heat the chamber up faster and improve cold start/warmup emissions and it's actually worse for performance. LOL. That would be pretty par for the course come to think of it. Ha, that sounds about right. I would be surprised if it weren't something along those lines. Like you said, I don't think there are any rigidity issues at all... Link to comment Share on other sites More sharing options...
Johann Posted June 30, 2009 Report Share Posted June 30, 2009 Exhaust port itself is also different. At some point also a divider was added to steer the coolant flow at the exhaust side of the block. Headgasket uses different diameter openings. Looks like some attention was given to evening out the coolant flow / temperature behavior. Link to comment Share on other sites More sharing options...
Captain Bondo Posted June 30, 2009 Author Report Share Posted June 30, 2009 Yeah that's kinda what I was thinking- it's a revision in "flow priority". So they took the bumps out of the ehxaust ports eh? Man volvo are a wierd bunch. I was thinking about hitting them with the die grinder before I put the head back on- not to remove them completely but to make them so they don't protrude out past where it looks like the flow wants to go... Link to comment Share on other sites More sharing options...
ajhehr Posted June 30, 2009 Report Share Posted June 30, 2009 I think the change also has something to do with the extra coolant tube that runs out of the driver side of the head back to the thermostat housing... I think maybe a velocity change? letting the coolant move faster through the head? Link to comment Share on other sites More sharing options...
EricF Posted June 30, 2009 Report Share Posted June 30, 2009 So they took the bumps out of the ehxaust ports eh? Man volvo are a wierd bunch. Maybe they realized their cam-timing induced warmup exhaust reversion worked better without them... Link to comment Share on other sites More sharing options...
Captain Bondo Posted July 1, 2009 Author Report Share Posted July 1, 2009 I went to the dealer to buy my headgasket today- he tried to sell me one for a 2001-2002. Get this- 1999 is one style, 2000 is the style Johann posted, and 2001-2002 is different again! The 01-02 gasket had NO coolant passage holes on the intake side! WTF? LOL. Link to comment Share on other sites More sharing options...
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