An absurd idea regarding 2.8s
10-07-2009, 01:09 AM
#17
Drifting
You would also have to deal with the timing belt - 4.5mm is a lot to add to the deck height and expect to use the stock belt length.
A set of custom pistons does not cost as much as it did several years ago - under $1k for Alusil pistons based on a custom design (relocated wrist pins) - plus you can get them in any compression ratio.
The other issue is that you are exposing a lot of head gasket material to the combustion area. Typically the head gasket is slightly recessed from the cylinder wall and is protected from the full combustion heat by type of quenching action - but it that face area goes from 1mm to 5.5mm then the actual flame front may contact the head gasket and transfer a lot more heat.
A set of custom pistons does not cost as much as it did several years ago - under $1k for Alusil pistons based on a custom design (relocated wrist pins) - plus you can get them in any compression ratio.
The other issue is that you are exposing a lot of head gasket material to the combustion area. Typically the head gasket is slightly recessed from the cylinder wall and is protected from the full combustion heat by type of quenching action - but it that face area goes from 1mm to 5.5mm then the actual flame front may contact the head gasket and transfer a lot more heat.
I know that you will be helping me get my car tuned perfectly, and I'm thankful for your help in advance. Granted, I'm a TEC customer, but I'll make your time worthwile in helping us get my car up to it's potential.
George
10-07-2009, 06:44 PM
#18
RL Community Team
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Thanks for the information.
There seems to be a misunderstanding. I do not intend to build a quick and dirty 2.8L. I am not interested in using a 5.5mm headgasket on an engine I would myself own. I was just sitting here daydreaming about engines when the thought occured to me and I just wanted to start a conversation about it, and learn why it would / wouldn't work.
That said, what if the headgasket were made of solid aluminum or copper? Would that help in its endurance of heat?
There seems to be a misunderstanding. I do not intend to build a quick and dirty 2.8L. I am not interested in using a 5.5mm headgasket on an engine I would myself own. I was just sitting here daydreaming about engines when the thought occured to me and I just wanted to start a conversation about it, and learn why it would / wouldn't work.
That said, what if the headgasket were made of solid aluminum or copper? Would that help in its endurance of heat?
10-07-2009, 07:26 PM
#19
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Thanks for the information.
There seems to be a misunderstanding. I do not intend to build a quick and dirty 2.8L. I am not interested in using a 5.5mm headgasket on an engine I would myself own. I was just sitting here daydreaming about engines when the thought occured to me and I just wanted to start a conversation about it, and learn why it would / wouldn't work.
That said, what if the headgasket were made of solid aluminum or copper? Would that help in its endurance of heat?
There seems to be a misunderstanding. I do not intend to build a quick and dirty 2.8L. I am not interested in using a 5.5mm headgasket on an engine I would myself own. I was just sitting here daydreaming about engines when the thought occured to me and I just wanted to start a conversation about it, and learn why it would / wouldn't work.
That said, what if the headgasket were made of solid aluminum or copper? Would that help in its endurance of heat?
BTW - for those of you guys (George) that are using Cometic gaskets - its important that you (or your mechanic) knows what to order. If you ask for a 100mm bore head gasket you will get a gasket with a 100mm hole – you really want a 100.5 or even a 101 so that the edge of the cometic gasket is slightly recessed and there for protected from direct combustion.
10-07-2009, 10:00 PM
#20
Team Owner
Agree, not that anyone would attempt this but this is sort of stuff run into all the time at work. Most of our machines are Italian made. Only one of the companies is big into spares in stock. So, every so often we have to get creative with mills, lathes and welders etc.
As for what I was referring to when suggesting a water jetted "spacer" out of titanium or stainless; It would for sure take two gaskets. Would have to do a crush test and measure to figure out a spacer thickness. And then just how far off the wall to recess back? As for the thinner domes from facing off that "extra" 4.5mm I'm thinking if ceramic coated the tops and maybe add oil squinters in the bottom end. (Like later 911's did to aid cooling). Wonder if we have exceeded the price of pistons yet?
As for belt geometry bet someplace in that serpentine rascal there is one of those rollers that could have a bit more adjustment added with an end mill slot. And.....why is we are doing this?
As for what I was referring to when suggesting a water jetted "spacer" out of titanium or stainless; It would for sure take two gaskets. Would have to do a crush test and measure to figure out a spacer thickness. And then just how far off the wall to recess back? As for the thinner domes from facing off that "extra" 4.5mm I'm thinking if ceramic coated the tops and maybe add oil squinters in the bottom end. (Like later 911's did to aid cooling). Wonder if we have exceeded the price of pistons yet?
As for belt geometry bet someplace in that serpentine rascal there is one of those rollers that could have a bit more adjustment added with an end mill slot. And.....why is we are doing this?