Some Darton MID Pics
04-17-2008, 07:29 AM
#61
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I didn't think you were trying to start anything. There are a hell of a lot more PCA folks, in the U.S., that don't ever come around RL, than you think. Many drive MUCH more expensive Porsche's daily.That's my point.
I responded with a question, to someone asking about street use. We both agree that this is a whole different ball of wax from a race app.
I can tell you that during my current project, I have as much as demanded that my engine be built with confidentiallity. I really don't give a **** what anyone thinks of my engine nor decisions. I sincerely doubt that I'm alone.
Bringing engine build experiences here is almost never worth the stupid bull**** one will have to listen too, from this board. Frankly, I think a good amount of what you get here are immature folks (regardless of age) seeking to prove that their tiny *****' were enlarged by their engines. Some are not.
The days of really good tech, here, are mostly long gone.
Anyway, in anything, it's usually the indian rather than the arrow.
This is sometimes a good source of info, but ALWAYS a great source of entertainment. It's also nice to make log distance friends with people like yourself. That's why I stay.
Anyway, I'm glad your project has finally turned out well for you. Cheers!
I responded with a question, to someone asking about street use. We both agree that this is a whole different ball of wax from a race app.
I can tell you that during my current project, I have as much as demanded that my engine be built with confidentiallity. I really don't give a **** what anyone thinks of my engine nor decisions. I sincerely doubt that I'm alone.
Bringing engine build experiences here is almost never worth the stupid bull**** one will have to listen too, from this board. Frankly, I think a good amount of what you get here are immature folks (regardless of age) seeking to prove that their tiny *****' were enlarged by their engines. Some are not.
The days of really good tech, here, are mostly long gone.
Anyway, in anything, it's usually the indian rather than the arrow.
This is sometimes a good source of info, but ALWAYS a great source of entertainment. It's also nice to make log distance friends with people like yourself. That's why I stay.
Anyway, I'm glad your project has finally turned out well for you. Cheers!
04-17-2008, 08:32 AM
#62
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Well I'm cool with your sentiment too so no probs on this side of the ball.
A couple of things though. I don't always think that being proud of one's car or driving tales is necessarily directly proportionate to the size of one's dick, well not all the time anyway. lol Depends on how far back you make your observation. A woman would say that we've all got some issues with it by spending so much time and money on our cars and forums associated. Then there's the my brand of car is superior to yours type of idiocy...that we've all felt at one stage or another too. Hell when I drive in my P car v's my beater, I just do feel different. Haven't had the opportunity to do a lot of direct comparisons though in the last few years, sob. Then there's the ridiculous inter brand snobbery that exists within the Porsche ranks. That still gets me, and also ironically spurs me on to greater heights. Funnily enough I don't want to show up any other brand of car on the track but the big boys in their way more expensive and more respected Porsches. That does drive me on. It will happen too. Not if, when!
Just to finish on the point that started this discussion. These cars that we're talking about being largely used as road cars for the most, and occasional trackers are still susceptible to 'cold slap' as you have to allow the clearances for the greatest temps, not the lowest. So on the track we can still get up to some very high piston temps and of course the commensurate expansion rates, so for this reason we have to leave much bigger clearances than eg the stock Mahles and stock Alusil bores. In fact down here JEs are known as 'Rattlers' in the motorsport arena.
I joined Rennlist pretty much at the end of an era I surmise. A changing of the guard. Going into some old threads from time to time doing research you see names that racked up many posts and perhaps there was more of a tech element. Shame to lose some of these contributors but that's just natural attrition. There are still some great posters here though and also some pretty funny irreverent ****e goes on that makes me laugh. I guess it's only a forum and as such open to all...within limits. Wonder if people have forum re-unions? Never thought of that. Be kinda interesting to see some past members and what they're up too. Seems and odd concept at first but then not really at all. Hmm one day...
A couple of things though. I don't always think that being proud of one's car or driving tales is necessarily directly proportionate to the size of one's dick, well not all the time anyway. lol Depends on how far back you make your observation. A woman would say that we've all got some issues with it by spending so much time and money on our cars and forums associated. Then there's the my brand of car is superior to yours type of idiocy...that we've all felt at one stage or another too. Hell when I drive in my P car v's my beater, I just do feel different. Haven't had the opportunity to do a lot of direct comparisons though in the last few years, sob. Then there's the ridiculous inter brand snobbery that exists within the Porsche ranks. That still gets me, and also ironically spurs me on to greater heights. Funnily enough I don't want to show up any other brand of car on the track but the big boys in their way more expensive and more respected Porsches. That does drive me on. It will happen too. Not if, when!
Just to finish on the point that started this discussion. These cars that we're talking about being largely used as road cars for the most, and occasional trackers are still susceptible to 'cold slap' as you have to allow the clearances for the greatest temps, not the lowest. So on the track we can still get up to some very high piston temps and of course the commensurate expansion rates, so for this reason we have to leave much bigger clearances than eg the stock Mahles and stock Alusil bores. In fact down here JEs are known as 'Rattlers' in the motorsport arena.
I joined Rennlist pretty much at the end of an era I surmise. A changing of the guard. Going into some old threads from time to time doing research you see names that racked up many posts and perhaps there was more of a tech element. Shame to lose some of these contributors but that's just natural attrition. There are still some great posters here though and also some pretty funny irreverent ****e goes on that makes me laugh. I guess it's only a forum and as such open to all...within limits. Wonder if people have forum re-unions? Never thought of that. Be kinda interesting to see some past members and what they're up too. Seems and odd concept at first but then not really at all. Hmm one day...
Last edited by 333pg333; 04-23-2008 at 02:14 AM.
04-17-2008, 10:02 AM
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Some interesting stuff here – lets see if I can toss out some info.
Piston clearance 1 – This is not a sleeve issue as much as it is a piston issue. No way would a sleeve (or block) manufacturer toss out a generic spec for this – check with the piston manufacturer.
Piston clearance 2 – Expansion rates are determined by several factors – alloy used and construction. There are two basic alloys – 2618 and 4032. 2618 is a little stronger but has a higher rate of expansion (about 15% higher).
So – ‘racers’ usually use a 2618 forging and live with the piston slap at cold start up. The clearance once at temp should be that same for both pistons. Piston noise when cold is a ‘non issue’ with a full race motor. It s not a real nice noise on a street engine but if you get the clearance right is should only make noise for a minute on a dead cold start on a typical day (starting at 30 degrees will take a little longer!)
As far as the holes in the MIDs – the rear ones line up with the passages to the head, the center two sleeves a lot less holes. The channels are all connected and should bleed the air back to the head. I don’t think that adding vents will help much.
If you are really worried about steam pockets check out Evans coolant (which is recommended by Darton by the way!). I like the stuff and use it myself.
As far as customers speaking up for themselves – that’s completely up to them. I don’t encourage it because I don’t want them draw any collateral fire that Rennlist seems to generate from time to time! They are out there – and from experience I can tell you that a ‘racer’ does not usually want to reveal anything that is working to their advantage and I certainly wouldn’t want to ‘out’ them!!!
Piston clearance 1 – This is not a sleeve issue as much as it is a piston issue. No way would a sleeve (or block) manufacturer toss out a generic spec for this – check with the piston manufacturer.
Piston clearance 2 – Expansion rates are determined by several factors – alloy used and construction. There are two basic alloys – 2618 and 4032. 2618 is a little stronger but has a higher rate of expansion (about 15% higher).
So – ‘racers’ usually use a 2618 forging and live with the piston slap at cold start up. The clearance once at temp should be that same for both pistons. Piston noise when cold is a ‘non issue’ with a full race motor. It s not a real nice noise on a street engine but if you get the clearance right is should only make noise for a minute on a dead cold start on a typical day (starting at 30 degrees will take a little longer!)
As far as the holes in the MIDs – the rear ones line up with the passages to the head, the center two sleeves a lot less holes. The channels are all connected and should bleed the air back to the head. I don’t think that adding vents will help much.
If you are really worried about steam pockets check out Evans coolant (which is recommended by Darton by the way!). I like the stuff and use it myself.
As far as customers speaking up for themselves – that’s completely up to them. I don’t encourage it because I don’t want them draw any collateral fire that Rennlist seems to generate from time to time! They are out there – and from experience I can tell you that a ‘racer’ does not usually want to reveal anything that is working to their advantage and I certainly wouldn’t want to ‘out’ them!!!
04-17-2008, 01:18 PM
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Any reason for choosing MID over dry sleeve? From what I understand, you would need much greater clearances with MIDs than with dry sleeves due to the properties of the sleeves which may not be too good for a car that sees some street use as it will be very noisy until it is at operating temp.
2) clearance is only an issue if the shop doesn't know what they're doing, but this is just my opinion. from what i understand when you use the j&e pistons, they heat up to operating temps within maybe one or two minutes. i normally warm my car up at least that long anyway so i don't see that as a problem.
04-18-2008, 09:52 PM
#66
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[QUOTE=nize;5322569
2) clearance is only an issue if the shop doesn't know what they're doing, but this is just my opinion. from what i understand when you use the j&e pistons, they heat up to operating temps within maybe one or two minutes. i normally warm my car up at least that long anyway so i don't see that as a problem.[/QUOTE]
Just for a reference point on my Darton sleeved, but not MID, engine with JE Pistons I used .006" clearance. I did not have any unusual piston noise at start up even in below freezing weather. I started at .0045" with coated pistons and thought things were ok until I took the head off to work on a head gasket. There was some light scoring so the block was honed out to get clearances of .006 to .0065 which I think has worked.
As said above the piston manufacturer knows, or should know, the expansion rates and the clearances when running in a given type of bore. Each engine machinist/builder will then use his/her experience to fine tune what the piston manufacturer says for a specific application.
Nize, let us know how it all comes out.
2) clearance is only an issue if the shop doesn't know what they're doing, but this is just my opinion. from what i understand when you use the j&e pistons, they heat up to operating temps within maybe one or two minutes. i normally warm my car up at least that long anyway so i don't see that as a problem.[/QUOTE]
Just for a reference point on my Darton sleeved, but not MID, engine with JE Pistons I used .006" clearance. I did not have any unusual piston noise at start up even in below freezing weather. I started at .0045" with coated pistons and thought things were ok until I took the head off to work on a head gasket. There was some light scoring so the block was honed out to get clearances of .006 to .0065 which I think has worked.
As said above the piston manufacturer knows, or should know, the expansion rates and the clearances when running in a given type of bore. Each engine machinist/builder will then use his/her experience to fine tune what the piston manufacturer says for a specific application.
Nize, let us know how it all comes out.
04-23-2008, 12:50 AM
#69
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