question 2.7 Sleeved block
04-22-2011, 03:48 AM
#63
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04-22-2011, 07:57 AM
#64
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Chris, the block is coming apart today, it's probably better to sell the bare block alone and let someone built the motor from scratch,
Second this is a 2.5L block sleeved to 2.7L?? 2.8L?? I am not sure now since I found documentation where the first owner described it as 2.8L, the bore dia is 105.5mm and I am not sure if it is a 3.L crank. It had a OEM steel flywheel lightened to 12lbs and stamped with a serial # and the flywheel has the similar # do you recognize this?
Second this is a 2.5L block sleeved to 2.7L?? 2.8L?? I am not sure now since I found documentation where the first owner described it as 2.8L, the bore dia is 105.5mm and I am not sure if it is a 3.L crank. It had a OEM steel flywheel lightened to 12lbs and stamped with a serial # and the flywheel has the similar # do you recognize this?
I doubt its an Andail motor – they supply pistons for various alusil based engines including the first 104mm turbo pistons and pistons for stroked turbo engines. it would not make sense for them to build up a sleeved engine.
Besides – I don’t see an ‘A’, I see a ‘V’….?
04-23-2011, 02:40 AM
#65
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Its really a 2.757 liter. The stock displacement is actually 2.477 and a 104mm bore is a 2.680 liter engine....but it much easier to round them up!
I doubt its an Andail motor – they supply pistons for various alusil based engines including the first 104mm turbo pistons and pistons for stroked turbo engines. it would not make sense for them to build up a sleeved engine.
Besides – I don’t see an ‘A’, I see a ‘V’….?
I doubt its an Andail motor – they supply pistons for various alusil based engines including the first 104mm turbo pistons and pistons for stroked turbo engines. it would not make sense for them to build up a sleeved engine.
Besides – I don’t see an ‘A’, I see a ‘V’….?
04-23-2011, 07:56 AM
#66
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Yes, that is somewhat typical for a dry sleeved motor, especially when they wanted to go all the way to 105.5 bore. The choice that the builder has to make is how to optimize the thickness of the alusil (for support) and steel (for strength). In this case they wanted to keep the steel sleeve as thick as possible. The Alusil on the upper side of the block floor is thicker than this and will offer more support –but it is still a little weaker than stock when it comes to keeping the cylinders from moving at high load.
04-23-2011, 01:53 PM
#67
Drifting
Chris,
Are you stating that a 2618 JE expands at a different rate than a 2618 Wossner? My block is not sleeved, the bores were NiCom treated.
Are you stating that a 2618 JE expands at a different rate than a 2618 Wossner? My block is not sleeved, the bores were NiCom treated.
A couple of thoughts – (some form early posts on this thread!)
Lart’s 2.7 looks like a good find – but I would highly recommend checking the deck height of the sleeves, if not done right the dry sleeves have a tendency to sink after a couple of good heat cycles and act exactly like the Ebay poster noted. A skim cut on the bock surface will fix that (easy enough with the engine out of the car).
The rod length of a 2.5 (and 2.6 or 2.7) is the same as the 2.8 or 3.0 – unless they are going to try the really old school short rod stroker (and that went out of style with parachute pants!)
Nothing wrong with the head gasket mod to use a 3.0 gasket on a 2.5 – you need to add a little RTV around the ‘ear’. I still use this on Oringed heads because the Orings don’t work well with MLS gaskets.
With the price of a used scored block being quite low there is no reason to repair a cracked block with welding. Get a sound block from Lart or use MID sleeves (the stock cylinder is machined out so a typical crack is not a problem).
As for ‘other’ pistons – I have been using Wossners for quite a while now, I like the product and just as important I like the way the company works – they send me engineering drawings if full detail before making the piston. I can spec anything out – compression ratio, pin height, ring type and location, cam design, box or regular bridging, quench shape and even an Alusil compatible coating. ($1k for the custom designed pistons, pins and rings – a little extra for Alusil coating!)
The JE 2618 alloy pistons have a greater thermal expansion rate than the stock pistons and the 4032 alloy aftermarket pistons. In my many years of building engines I have found one pretty basic rule with sleeved motors – if you use a JE 2618 alloy pistons and don’t hear a little piston slap on start up then you are going to have issues when you run the engine hard. If the ambient temp is low it sounds worse. Under 50 degree air temps it should sound like a worn out Cummings for the first minute, the slap goes away as it warms up. Remember –this applies to sleeved engines – I have not used JEs in a Alusil bore.
And just in case anybody still has a question - the 2.7 engine IS a 3.0 block with a 2.5 crank in it.
The cam design on any custom piston should be exactly as the builder specs – I know that I spec out what I want. If you ask for ‘off the shelf’ designs from a piston manufacturer you will get whatever they feel like giving you. If you ask for a 944 piston from JE and don’t provide some exacting specs you will get a piston with the Chevy valve reliefs pockets still showing on the underside on the piston (as ‘Modded’ said!). That’s quite a few grams of wasted weight as well as some proof that the original forging was not intended for a 944….
Sorry for the disjointed answers…I am catching up – been too busy to do the daily Rennlist checks this week!
Lart’s 2.7 looks like a good find – but I would highly recommend checking the deck height of the sleeves, if not done right the dry sleeves have a tendency to sink after a couple of good heat cycles and act exactly like the Ebay poster noted. A skim cut on the bock surface will fix that (easy enough with the engine out of the car).
The rod length of a 2.5 (and 2.6 or 2.7) is the same as the 2.8 or 3.0 – unless they are going to try the really old school short rod stroker (and that went out of style with parachute pants!)
Nothing wrong with the head gasket mod to use a 3.0 gasket on a 2.5 – you need to add a little RTV around the ‘ear’. I still use this on Oringed heads because the Orings don’t work well with MLS gaskets.
With the price of a used scored block being quite low there is no reason to repair a cracked block with welding. Get a sound block from Lart or use MID sleeves (the stock cylinder is machined out so a typical crack is not a problem).
As for ‘other’ pistons – I have been using Wossners for quite a while now, I like the product and just as important I like the way the company works – they send me engineering drawings if full detail before making the piston. I can spec anything out – compression ratio, pin height, ring type and location, cam design, box or regular bridging, quench shape and even an Alusil compatible coating. ($1k for the custom designed pistons, pins and rings – a little extra for Alusil coating!)
The JE 2618 alloy pistons have a greater thermal expansion rate than the stock pistons and the 4032 alloy aftermarket pistons. In my many years of building engines I have found one pretty basic rule with sleeved motors – if you use a JE 2618 alloy pistons and don’t hear a little piston slap on start up then you are going to have issues when you run the engine hard. If the ambient temp is low it sounds worse. Under 50 degree air temps it should sound like a worn out Cummings for the first minute, the slap goes away as it warms up. Remember –this applies to sleeved engines – I have not used JEs in a Alusil bore.
And just in case anybody still has a question - the 2.7 engine IS a 3.0 block with a 2.5 crank in it.
The cam design on any custom piston should be exactly as the builder specs – I know that I spec out what I want. If you ask for ‘off the shelf’ designs from a piston manufacturer you will get whatever they feel like giving you. If you ask for a 944 piston from JE and don’t provide some exacting specs you will get a piston with the Chevy valve reliefs pockets still showing on the underside on the piston (as ‘Modded’ said!). That’s quite a few grams of wasted weight as well as some proof that the original forging was not intended for a 944….
Sorry for the disjointed answers…I am catching up – been too busy to do the daily Rennlist checks this week!
04-23-2011, 02:01 PM
#68
Drifting
Chris,
Are you stating that a 2618 JE expands at a different rate than a 2618 Wossner? My block is not sleeved, the bores were NiCom treated.
Are you stating that a 2618 JE expands at a different rate than a 2618 Wossner? My block is not sleeved, the bores were NiCom treated.
A couple of thoughts – (some form early posts on this thread!)
Lart’s 2.7 looks like a good find – but I would highly recommend checking the deck height of the sleeves, if not done right the dry sleeves have a tendency to sink after a couple of good heat cycles and act exactly like the Ebay poster noted. A skim cut on the bock surface will fix that (easy enough with the engine out of the car).
The rod length of a 2.5 (and 2.6 or 2.7) is the same as the 2.8 or 3.0 – unless they are going to try the really old school short rod stroker (and that went out of style with parachute pants!)
Nothing wrong with the head gasket mod to use a 3.0 gasket on a 2.5 – you need to add a little RTV around the ‘ear’. I still use this on Oringed heads because the Orings don’t work well with MLS gaskets.
With the price of a used scored block being quite low there is no reason to repair a cracked block with welding. Get a sound block from Lart or use MID sleeves (the stock cylinder is machined out so a typical crack is not a problem).
As for ‘other’ pistons – I have been using Wossners for quite a while now, I like the product and just as important I like the way the company works – they send me engineering drawings if full detail before making the piston. I can spec anything out – compression ratio, pin height, ring type and location, cam design, box or regular bridging, quench shape and even an Alusil compatible coating. ($1k for the custom designed pistons, pins and rings – a little extra for Alusil coating!)
The JE 2618 alloy pistons have a greater thermal expansion rate than the stock pistons and the 4032 alloy aftermarket pistons. In my many years of building engines I have found one pretty basic rule with sleeved motors – if you use a JE 2618 alloy pistons and don’t hear a little piston slap on start up then you are going to have issues when you run the engine hard. If the ambient temp is low it sounds worse. Under 50 degree air temps it should sound like a worn out Cummings for the first minute, the slap goes away as it warms up. Remember –this applies to sleeved engines – I have not used JEs in a Alusil bore.
And just in case anybody still has a question - the 2.7 engine IS a 3.0 block with a 2.5 crank in it.
The cam design on any custom piston should be exactly as the builder specs – I know that I spec out what I want. If you ask for ‘off the shelf’ designs from a piston manufacturer you will get whatever they feel like giving you. If you ask for a 944 piston from JE and don’t provide some exacting specs you will get a piston with the Chevy valve reliefs pockets still showing on the underside on the piston (as ‘Modded’ said!). That’s quite a few grams of wasted weight as well as some proof that the original forging was not intended for a 944….
Sorry for the disjointed answers…I am catching up – been too busy to do the daily Rennlist checks this week!
Lart’s 2.7 looks like a good find – but I would highly recommend checking the deck height of the sleeves, if not done right the dry sleeves have a tendency to sink after a couple of good heat cycles and act exactly like the Ebay poster noted. A skim cut on the bock surface will fix that (easy enough with the engine out of the car).
The rod length of a 2.5 (and 2.6 or 2.7) is the same as the 2.8 or 3.0 – unless they are going to try the really old school short rod stroker (and that went out of style with parachute pants!)
Nothing wrong with the head gasket mod to use a 3.0 gasket on a 2.5 – you need to add a little RTV around the ‘ear’. I still use this on Oringed heads because the Orings don’t work well with MLS gaskets.
With the price of a used scored block being quite low there is no reason to repair a cracked block with welding. Get a sound block from Lart or use MID sleeves (the stock cylinder is machined out so a typical crack is not a problem).
As for ‘other’ pistons – I have been using Wossners for quite a while now, I like the product and just as important I like the way the company works – they send me engineering drawings if full detail before making the piston. I can spec anything out – compression ratio, pin height, ring type and location, cam design, box or regular bridging, quench shape and even an Alusil compatible coating. ($1k for the custom designed pistons, pins and rings – a little extra for Alusil coating!)
The JE 2618 alloy pistons have a greater thermal expansion rate than the stock pistons and the 4032 alloy aftermarket pistons. In my many years of building engines I have found one pretty basic rule with sleeved motors – if you use a JE 2618 alloy pistons and don’t hear a little piston slap on start up then you are going to have issues when you run the engine hard. If the ambient temp is low it sounds worse. Under 50 degree air temps it should sound like a worn out Cummings for the first minute, the slap goes away as it warms up. Remember –this applies to sleeved engines – I have not used JEs in a Alusil bore.
And just in case anybody still has a question - the 2.7 engine IS a 3.0 block with a 2.5 crank in it.
The cam design on any custom piston should be exactly as the builder specs – I know that I spec out what I want. If you ask for ‘off the shelf’ designs from a piston manufacturer you will get whatever they feel like giving you. If you ask for a 944 piston from JE and don’t provide some exacting specs you will get a piston with the Chevy valve reliefs pockets still showing on the underside on the piston (as ‘Modded’ said!). That’s quite a few grams of wasted weight as well as some proof that the original forging was not intended for a 944….
Sorry for the disjointed answers…I am catching up – been too busy to do the daily Rennlist checks this week!
04-23-2011, 02:40 PM
#69
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04-23-2011, 03:12 PM
#70
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Lart, I have to say.. Excellent thread. I am so happy to see how civil everyone has been on such volatile topics.
My opinions, and only that;
1. You have an excellent starting point. Great block with potential in either direction. extreme disaster or success. I think it's just absolutely necessary to check deck height before moving on with build.. It is extremely cheap at this point and is a perfect time to do it since the block has already had its heat cycles. I WOULD have bought this block if it were time to start building a motor I didn't already have.
2.) So many people will hear a piston tolerance for the 2.5, and put it in the 2.7 or 3.0. Nope. The 2.7 and the 3.0 are larger pistons with more surface area. Therefore will expand more and need a different clearance. ALSO. The "correct" clearances are always different if you are mating a steel sleeved liner and 2618 piston, compared to 2618 piston and a stock Alusil one. They will expand and contract at different rates. SO.. it's always up to the builder to get it right.
Lart, you have always done a fantastic job of supplying myself parts and I will always recommend you.
Oh, and I saw you new website. www.lartsperformanceparts.com That's awesome! I can't wait until its finished so I can just browse from there whenever I need one of my crazy parts again.
My opinions, and only that;
1. You have an excellent starting point. Great block with potential in either direction. extreme disaster or success. I think it's just absolutely necessary to check deck height before moving on with build.. It is extremely cheap at this point and is a perfect time to do it since the block has already had its heat cycles. I WOULD have bought this block if it were time to start building a motor I didn't already have.
2.) So many people will hear a piston tolerance for the 2.5, and put it in the 2.7 or 3.0. Nope. The 2.7 and the 3.0 are larger pistons with more surface area. Therefore will expand more and need a different clearance. ALSO. The "correct" clearances are always different if you are mating a steel sleeved liner and 2618 piston, compared to 2618 piston and a stock Alusil one. They will expand and contract at different rates. SO.. it's always up to the builder to get it right.
Lart, you have always done a fantastic job of supplying myself parts and I will always recommend you.
Oh, and I saw you new website. www.lartsperformanceparts.com That's awesome! I can't wait until its finished so I can just browse from there whenever I need one of my crazy parts again.
04-23-2011, 07:09 PM
#71
Drifting
