Fishey Posted January 2, 2011 Report Share Posted January 2, 2011 Here is my take on what head to run is 50/50. Early heads have advantages and late heads have advantages its all personal preference. I can simply say that to make an argument that one is 100% better then the other is simply wrong. I have to say that it all depends on what kind of work you want to put into them. Late Heads will outflow Early heads but it has very little to do with stem size but the fact that late heads have a multi-angle valve cut from the factory. Early heads have a single cut and the earlier 94-95 heads have some serious manufacturing defects that can significantly effect flow. Early Heads respond much better to Porting/Valve Cutting then the later heads obviously there is more room for improvement in the early heads. Also, the early heads actually have a better port shape. However, Later heads have solid lifters and as a result have a much better cam profile but have to disable there VVT system. I would guess however that the general shape and design of the cams are still better. That being said I do wonder a bit about duration on the early cams vs late cams (Forget specs) as it could have some effect on how good the later cams actually perform without VVT installed. -Your Pal Fishey Link to comment Share on other sites More sharing options...
lookforjoe Posted January 2, 2011 Author Report Share Posted January 2, 2011 Here is my take on what head to run is 50/50. Late Heads will outflow Early heads but it has very little to do with stem size but the fact that late heads have a multi-angle valve cut from the factory. Early heads have a single cut and the earlier 94-95 heads have some serious manufacturing defects that can significantly effect flow. Early Heads respond much better to Porting/Valve Cutting then the later heads obviously there is more room for improvement in the early heads. Also, the early heads actually have a better port shape. However, Later heads have solid lifters and as a result have a much better cam profile but have to disable there VVT system. I would guess however that the general shape and design of the cams are still better. That being said I do wonder a bit about duration on the early cams vs late cams (Forget specs) as it could have some effect on how good the later cams actually perform without VVT installed. -Your Pal Fishey I saw you post that in the other cyl head thread, but I'm not sure that you are correct. My '98 head was redone when I built the motor, and the shop did the standard 3-angle grind. They did not remark that the 3 angle was absent from the valves when they took them out. The extensive info in the various threads indicate that the intake ports are at least 20% larger, the cams have greater lift - what's not to like? :lol: Link to comment Share on other sites More sharing options...
TRACStar Posted January 2, 2011 Report Share Posted January 2, 2011 The extensive info in the various threads indicate that the intake ports are at least 20% larger, the cams have greater lift - what's not to like? They are larger in an untouched factory head, but if you had plans to have some porting done anyway is there an advantage aside from the lifers? Link to comment Share on other sites More sharing options...
lookforjoe Posted January 2, 2011 Author Report Share Posted January 2, 2011 They are larger in an untouched factory head, but if you had plans to have some porting done anyway is there an advantage aside from the lifers? If you read through some of the other threads - the knowledgeable porting & testing that would be required to get significant gains out of an early head do not match the $$$ investment vs. using a later head, esp. when you also factor the solid lifters & better cams, that's my understanding of the situation Link to comment Share on other sites More sharing options...
Fishey Posted January 2, 2011 Report Share Posted January 2, 2011 I saw you post that in the other cyl head thread, but I'm not sure that you are correct. My '98 head was redone when I built the motor, and the shop did the standard 3-angle grind. They did not remark that the 3 angle was absent from the valves when they took them out. The extensive info in the various threads indicate that the intake ports are at least 20% larger, the cams have greater lift - what's not to like? Hold on seriously, Early head exhaust valve, Clearly single cut. Also, I have to wonder about this "Standard 3-angle grind". The early Volvo cylinder head has no top cut or bottom cut on the valve regardless of year. (As shown in picture) Also, the exhaust valve does not have any sort of base cut on it but does have a very minimal radius. The early cylinder heads do have a 3 angle seat cut 30top/45seat/60throat but lack a good transition cut at the choke. Then again, late head ports are 20% larger Also how does that work with the throat cut? You only want to be about 88/89 percent of your valve size on your throat cut. You push it into 91/92 range and your going to see a big drop in CFM as flow starts to stall. Since we know that valve size pretty much identical on both heads how does that work with 20% larger ports? Link to comment Share on other sites More sharing options...
lookforjoe Posted January 2, 2011 Author Report Share Posted January 2, 2011 Hold on seriously, Early head exhaust valve, Clearly single cut. Also, I have to wonder about this "Standard 3-angle grind". The early Volvo cylinder head has no top cut or bottom cut on the valve regardless of year. (As shown in picture) Also, the exhaust valve does not have any sort of base cut on it but does have a very minimal radius. The early cylinder heads do have a 3 angle seat cut 30/45/60 but lack a good transition cut at the choke. Then again, they are 20% larger What year is that valve? What is your definition of "early"? All your remarks seem pointed at pre-98, I haven't seen you post any pics of actual '98 valves/seats Link to comment Share on other sites More sharing options...
Fishey Posted January 2, 2011 Report Share Posted January 2, 2011 What year is that valve? What is your definition of "early"? All your remarks seem pointed at pre-98, I haven't seen you post any pics of actual '98 valves/seats I have seen no evidence that would conclude that a 98 head would change from a 97 head. Also all 94-97 turbo heads are identical except for intake valves but even they have the same single cut angle. -Your Pal Fishey Link to comment Share on other sites More sharing options...
lookforjoe Posted January 2, 2011 Author Report Share Posted January 2, 2011 I have seen no evidence that would conclude that a 98 head would change from a 97 head. Also all 94-97 turbo heads are identical except for intake valves but even they have the same single cut angle. -Your Pal Fishey Whatever, man. I'm not gonna argue with you. Others have indicated advantages to be gained in the improved overall flow of the later head, I'm going with their assessment. Link to comment Share on other sites More sharing options...
Fishey Posted January 2, 2011 Report Share Posted January 2, 2011 Whatever, man. I'm not gonna argue with you. Others have indicated advantages to be gained in the improved overall flow of the later head, I'm going with their assessment. Yea, Clearly I have no idea what I am talking about or any real world experience. :( Link to comment Share on other sites More sharing options...
lookforjoe Posted January 2, 2011 Author Report Share Posted January 2, 2011 Yea, Clearly I have no idea what I am talking about or any real world experience. I don't know, do you? I see much theory posted, and I haven't seen any threads on any builds or performance work you have actually done on here... hell, there's not even a car/sig on your posts.... Link to comment Share on other sites More sharing options...
mdlimy Posted January 2, 2011 Report Share Posted January 2, 2011 Yea, Clearly I have no idea what I am talking about or any real world experience. me7 heads> m4.3/4 Link to comment Share on other sites More sharing options...
ozzimark Posted January 2, 2011 Report Share Posted January 2, 2011 H-man, I wasn't clear enough, sorry I posted that pic to show how the valve lash was excessively large, causing an oil varnish buildup on the back side of the cam lobes. If it was set properly, there shouldn't be enough clearance when the engine is hot for that layer to build up. Or at least I imagine it should be that way, when considering how my '98 hydraulic lifter cams look. Fishey, that looks like a valve from a '93/94 head? Link to comment Share on other sites More sharing options...
loseR99 Posted January 2, 2011 Report Share Posted January 2, 2011 A quick vadis search will show that the 01'+ head flows the best. The 01' specifically has VVT (exhaust only) and hotter cams, highest lift on both exhaust and intake (per VADIS chart). Link to comment Share on other sites More sharing options...
Fishey Posted January 2, 2011 Report Share Posted January 2, 2011 H-man, I wasn't clear enough, sorry I posted that pic to show how the valve lash was excessively large, causing an oil varnish buildup on the back side of the cam lobes. If it was set properly, there shouldn't be enough clearance when the engine is hot for that layer to build up. Or at least I imagine it should be that way, when considering how my '98 hydraulic lifter cams look. Fishey, that looks like a valve from a '93/94 head? That valve is from a 96 Volvo 850 Turbo Exhaust side. The Exhaust valves from 94-96 on the turbo's are all identical but intake changed in 96 but still has the same single seat cut. I am not 100% sure about the 98's but I have no reason to belive they are any different then the 94-97 turbo heads. I don't know, do you? I see much theory posted, and I haven't seen any threads on any builds or performance work you have actually done on here... hell, there's not even a car/sig on your posts.... I don't bring up work that much but here are a few pictures of where I am working now. Also, here is what I did today. I assembled multiple brake disk assemblys for the Rolex Protype. Anyways, I am not saying early heads are better stock vs stock they are not. Even moddified they both have advantages/disadvantages. I am just saying that its not as clear cut as some other people might make it seem. Don't get angry when I bring relevent information to the table and openly share my information with the community. -Your Pal Fishey Link to comment Share on other sites More sharing options...
ozzimark Posted January 2, 2011 Report Share Posted January 2, 2011 I'm 99% sure the 98 valves are the same as the year before. Nice pics of the garage you work in. I'm kinda jealous. Got a flow bench hidden away in there? :) Link to comment Share on other sites More sharing options...
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