Engine build time
12-30-2008, 02:09 PM
#21
That really sucks...but a good excuse to upgrade! I have an 03 long block...with 30k miles...but it's too nice to rebuild. I would assume anyway....
BTW, duffins did the balancing on my race engine for the Cobra...I'll let you know how it goes in another week or two...
BTW, duffins did the balancing on my race engine for the Cobra...I'll let you know how it goes in another week or two...
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01-11-2009, 07:15 PM
#23
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So tearing down the engine today I discovered a lot of oil in the intake manifold. This is not the usual PVC blow-by accumulation, but small pools of engine oil in the intake manifold. There was also some in the passages of the throttle body (not the coolant circuit). I discovered it when I pulled off the throttle body and all of this motor oil came dripping out. It was definitely a WTF moment. The oil is all downstream of the throttle. The rest of the intake plumbing, including the IC, is spotless.
The #4 plug was soaked with oil when I removed it.
So I am thinking one of two things happened here:
1. If the piston is broken, it leaked a LOT of oil into the cylinder, which was then sprayed into the intake when the valve opened. The engine rotated a few times of course after it blew (before I could shut it off and put it in neutral).
2. A blown head gasket leaked oil into the cylinder. This could have in fact precipitated the failure. But, there is NO coolant in the oil and NO oil in the coolant. I checked them both when I drained the fluids from the engine. The coolant looks fantastic in fact.
The #4 plug was soaked with oil when I removed it.
So I am thinking one of two things happened here:
1. If the piston is broken, it leaked a LOT of oil into the cylinder, which was then sprayed into the intake when the valve opened. The engine rotated a few times of course after it blew (before I could shut it off and put it in neutral).
2. A blown head gasket leaked oil into the cylinder. This could have in fact precipitated the failure. But, there is NO coolant in the oil and NO oil in the coolant. I checked them both when I drained the fluids from the engine. The coolant looks fantastic in fact.
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01-11-2009, 07:38 PM
#25
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Here are some pictures of what I am talking about. The dark pools under the VICS butterflies are pools of oil. It did not look like this the last time I had the upper intake manifold off. In fact, none of this stuff looked like this.
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01-11-2009, 07:40 PM
#26
So tearing down the engine today I discovered a lot of oil in the intake manifold. This is not the usual PVC blow-by accumulation, but small pools of engine oil in the intake manifold. There was also some in the passages of the throttle body (not the coolant circuit). I discovered it when I pulled off the throttle body and all of this motor oil came dripping out. It was definitely a WTF moment. The oil is all downstream of the throttle. The rest of the intake plumbing, including the IC, is spotless.
The #4 plug was soaked with oil when I removed it.
So I am thinking one of two things happened here:
1. If the piston is broken, it leaked a LOT of oil into the cylinder, which was then sprayed into the intake when the valve opened. The engine rotated a few times of course after it blew (before I could shut it off and put it in neutral).
2. A blown head gasket leaked oil into the cylinder. This could have in fact precipitated the failure. But, there is NO coolant in the oil and NO oil in the coolant. I checked them both when I drained the fluids from the engine. The coolant looks fantastic in fact.
The #4 plug was soaked with oil when I removed it.
So I am thinking one of two things happened here:
1. If the piston is broken, it leaked a LOT of oil into the cylinder, which was then sprayed into the intake when the valve opened. The engine rotated a few times of course after it blew (before I could shut it off and put it in neutral).
2. A blown head gasket leaked oil into the cylinder. This could have in fact precipitated the failure. But, there is NO coolant in the oil and NO oil in the coolant. I checked them both when I drained the fluids from the engine. The coolant looks fantastic in fact.
I hope you find the "cause" of this failure. You have me worried.
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01-11-2009, 07:47 PM
#28
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Yes that is metal flakes in the pictures of the throttle body and the intake manifold next to the throttle body.
The #1 spark plug looked fine. The #4 plug is the one with all the oil on it.
The #1 spark plug looked fine. The #4 plug is the one with all the oil on it.
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01-12-2009, 08:12 PM
#29
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I just ordered the full engine kit from Belfab, which from what I can tell is a good deal with the sale they are having. This should make for a nice motor.
BELFAB RACING PRODUCTS
By the way, their web site is a bit messed up according to the owner at Belfab. The Supertech pistons are available in a 9.0:1 compression ratio, at least in the 1.8L. Also, according to the owner, there are only two of these Miata kits left, so if you want one...
BELFAB RACING PRODUCTS
By the way, their web site is a bit messed up according to the owner at Belfab. The Supertech pistons are available in a 9.0:1 compression ratio, at least in the 1.8L. Also, according to the owner, there are only two of these Miata kits left, so if you want one...
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01-12-2009, 09:59 PM
#30
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I just ordered the full engine kit from Belfab, which from what I can tell is a good deal with the sale they are having. This should make for a nice motor.
BELFAB RACING PRODUCTS
By the way, their web site is a bit messed up according to the owner at Belfab. The Supertech pistons are available in a 9.0:1 compression ratio, at least in the 1.8L. Also, according to the owner, there are only two of these Miata kits left, so if you want one...
BELFAB RACING PRODUCTS
By the way, their web site is a bit messed up according to the owner at Belfab. The Supertech pistons are available in a 9.0:1 compression ratio, at least in the 1.8L. Also, according to the owner, there are only two of these Miata kits left, so if you want one...
Trey, the 8.6:1 pistons will work for 9.0:1 compression ratio range, this how you get the added ratio......Your stock Miata Head cc's is 50, the Dome Dish for the Piston is -4, the standard Gasket Thickness is .079, which give you a Deck Clearance of 0.5- ,this get you a Comp. Ratio of 8.6:1, now this what you can do.........Head cc's @ 50 use a Gasket Thickness of .031, this will change the deck clearance to .020-, Piston -4, the ratio will increase to 9.0:1
Always run at least .030 piston to head clearance including gasket thickness, a compression ratio range: low number is with un-cut deck, high number is block decked to .030 piston to cylinder head clearance, Always check piston to valve clearance however the Valve Pocket design of the Supertech pistons allows for maximum flow around valve, also allowing oversized valves and high lift cams to be utilized, THEY WILL WORK
Jim
Always run at least .030 piston to head clearance including gasket thickness, a compression ratio range: low number is with un-cut deck, high number is block decked to .030 piston to cylinder head clearance, Always check piston to valve clearance however the Valve Pocket design of the Supertech pistons allows for maximum flow around valve, also allowing oversized valves and high lift cams to be utilized, THEY WILL WORK
Jim
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01-12-2009, 10:31 PM
#31
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Yes I thought I might have to play that game if all they had was the 8.5:1 as indicated on their web site. Either that or get 9.5:1. What compr ratios are available on their site depends on what link you click, which is confusing.
So I called them and asked what they had. They have actual 9.0:1 pistons which they added more recently to cater to the moderate boost turbo crowd. According to the owner the webmaster has not updated the link yet. So apparently they come (or in past and present collectively) in 8.5:1, 9.0:1, 9.5:1, and 11.0:1.
So I called them and asked what they had. They have actual 9.0:1 pistons which they added more recently to cater to the moderate boost turbo crowd. According to the owner the webmaster has not updated the link yet. So apparently they come (or in past and present collectively) in 8.5:1, 9.0:1, 9.5:1, and 11.0:1.
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01-13-2009, 08:49 AM
#34
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i had some fitment issues with the gasket kit, and they sent me an escort water pump. I could have sent it back and scored the right stuff, but didn't have time for that when the motor was sitting at the machine shop.
Also, how can you order bearings before you have the motor yanked apart and everything measured?
Also, how can you order bearings before you have the motor yanked apart and everything measured?
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01-13-2009, 09:46 AM
#35
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Good question. There is a good chance the crank will still want the standard bearings. If not, I can swap them out with what I need, no charge. The motor is at the machine shop now so I'll know soon anyway.
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01-17-2009, 03:19 PM
#37
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Update:
Turns out the donor short block I had to replace the one above had a bad crank in it due to a badly spun bearing. So, the engine shown above will be coming out next weekend and hopefully its crank and head
are still good. That way all I need from the donor short block is the block itself.
ARP main bearing and head studs are ordered.
Turns out the donor short block I had to replace the one above had a bad crank in it due to a badly spun bearing. So, the engine shown above will be coming out next weekend and hopefully its crank and head
are still good. That way all I need from the donor short block is the block itself. ARP main bearing and head studs are ordered.
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