97 Miata forged engine build
#1
97 Miata forged engine build
Current setup: 1997 Miata 150k miles, full Mkturbo kit (ms3pnppro, 640cc injectors, supermiata stage1 clutch), stock engine, stock 5 speed
Goal: 300ish whp. Car is used for occasional autox and weekend fun. Would like to get more involved in track days but haven't done any yet.
The plan: build engine forged, buy EFR6258 after I pay off the engine build.
Parts List:
Supertech 8.6:1 84mm pistons with wiseco xx rings
Manley H beam rods
ARP Head and Main stud kits
ACL race bearings
Boundary Engineering oil pump w/ 2 shims
Cometic .030 head gasket
complete front engine kit (Kevlar belt, water pump, seals)
Supermiata hybrid motor mount it
qmax coolant reroute
crossflow radiator
supermiata valve seals
Do you see anything missing? the total for those parts is $2600. buying everything from Fab9 or supermiata. If you know of a cheaper vendor let me know. I found a reputable machine shop and was quoted around $450 to bore, hone, clean, deck the block, and clean/inspect the head. I am going to leave the head alone (other than change valve seals) unless yall tell me anything needs done to it.
Not sure if I need COPS at this level? Not sure how long the 5 speed will hold on at this level either.
Have I gone overbored on anything? I don't want to spend too much, but I also don't want to cheap out while I have the engine out of the car. I was thinking about adding a damper, but figured I can do that later and it isn't necessary for 300-350whp range. I also plan on keeping the 7200rpm red line. This will be my first time building an engine. I am excited to do it, but I am getting deployed in 2 months so it is either pull the trigger now or wait 6 months.
Goal: 300ish whp. Car is used for occasional autox and weekend fun. Would like to get more involved in track days but haven't done any yet.
The plan: build engine forged, buy EFR6258 after I pay off the engine build.
Parts List:
Supertech 8.6:1 84mm pistons with wiseco xx rings
Manley H beam rods
ARP Head and Main stud kits
ACL race bearings
Boundary Engineering oil pump w/ 2 shims
Cometic .030 head gasket
complete front engine kit (Kevlar belt, water pump, seals)
Supermiata hybrid motor mount it
qmax coolant reroute
crossflow radiator
supermiata valve seals
Do you see anything missing? the total for those parts is $2600. buying everything from Fab9 or supermiata. If you know of a cheaper vendor let me know. I found a reputable machine shop and was quoted around $450 to bore, hone, clean, deck the block, and clean/inspect the head. I am going to leave the head alone (other than change valve seals) unless yall tell me anything needs done to it.
Not sure if I need COPS at this level? Not sure how long the 5 speed will hold on at this level either.
Have I gone overbored on anything? I don't want to spend too much, but I also don't want to cheap out while I have the engine out of the car. I was thinking about adding a damper, but figured I can do that later and it isn't necessary for 300-350whp range. I also plan on keeping the 7200rpm red line. This will be my first time building an engine. I am excited to do it, but I am getting deployed in 2 months so it is either pull the trigger now or wait 6 months.
#5
The Cometic .030 head gasket might be a problem.
If the pistons protrude from the block (positive deck height) .030 is too small.
It is hard to set a minimum clearance, especially with forged pistons as they have more piston to bore clearance than cast.
Minimum clearance with cast .032/.035
Forged .040-.045
I love good quench. Less piston to head clearance the better,
But, the only indication of setting this clearance too close is damaged pistons...
Quench helps reduce detonation by shortening burn time (which also reduces required advance in timing).
Being at 8.6/1 also helps reduce detonation.
Be careful of final installed deck height with a skinny head gasket.
I'd run .045 with what you are building.
If the Supertech pistons sit .015 below deck height then the .030 is perfect!
I usually do an initial "mock" assembly after the boring is finished to check deck height (on both #1 and #4) before ordering the head gasket...
Only thing that is overkill for your build is the ARP main studs.
If your machine shop is good they can properly fit them. They really require main bore alignment checks and possible adjustment and many machine shops cannot handle this properly.
I agree with Six regarding the oil pump shims as well. Not needed for street car. Before I added the shims I'd chose the VVT pump (wider gears and more volume).
Both the .030 head gasket and the ARP main studs require a "wizard" for proper installation.
If the pistons protrude from the block (positive deck height) .030 is too small.
It is hard to set a minimum clearance, especially with forged pistons as they have more piston to bore clearance than cast.
Minimum clearance with cast .032/.035
Forged .040-.045
I love good quench. Less piston to head clearance the better,
But, the only indication of setting this clearance too close is damaged pistons...
Quench helps reduce detonation by shortening burn time (which also reduces required advance in timing).
Being at 8.6/1 also helps reduce detonation.
Be careful of final installed deck height with a skinny head gasket.
I'd run .045 with what you are building.
If the Supertech pistons sit .015 below deck height then the .030 is perfect!
I usually do an initial "mock" assembly after the boring is finished to check deck height (on both #1 and #4) before ordering the head gasket...
Only thing that is overkill for your build is the ARP main studs.
If your machine shop is good they can properly fit them. They really require main bore alignment checks and possible adjustment and many machine shops cannot handle this properly.
I agree with Six regarding the oil pump shims as well. Not needed for street car. Before I added the shims I'd chose the VVT pump (wider gears and more volume).
Both the .030 head gasket and the ARP main studs require a "wizard" for proper installation.
#7
The Cometic .030 head gasket might be a problem.
If the pistons protrude from the block (positive deck height) .030 is too small.
It is hard to set a minimum clearance, especially with forged pistons as they have more piston to bore clearance than cast.
Minimum clearance with cast .032/.035
Forged .040-.045
I love good quench. Less piston to head clearance the better,
But, the only indication of setting this clearance too close is damaged pistons...
Quench helps reduce detonation by shortening burn time (which also reduces required advance in timing).
Being at 8.6/1 also helps reduce detonation.
Be careful of final installed deck height with a skinny head gasket.
I'd run .045 with what you are building.
If the Supertech pistons sit .015 below deck height then the .030 is perfect!
I usually do an initial "mock" assembly after the boring is finished to check deck height (on both #1 and #4) before ordering the head gasket...
Only thing that is overkill for your build is the ARP main studs.
If your machine shop is good they can properly fit them. They really require main bore alignment checks and possible adjustment and many machine shops cannot handle this properly.
I agree with Six regarding the oil pump shims as well. Not needed for street car. Before I added the shims I'd chose the VVT pump (wider gears and more volume).
Both the .030 head gasket and the ARP main studs require a "wizard" for proper installation.
If the pistons protrude from the block (positive deck height) .030 is too small.
It is hard to set a minimum clearance, especially with forged pistons as they have more piston to bore clearance than cast.
Minimum clearance with cast .032/.035
Forged .040-.045
I love good quench. Less piston to head clearance the better,
But, the only indication of setting this clearance too close is damaged pistons...
Quench helps reduce detonation by shortening burn time (which also reduces required advance in timing).
Being at 8.6/1 also helps reduce detonation.
Be careful of final installed deck height with a skinny head gasket.
I'd run .045 with what you are building.
If the Supertech pistons sit .015 below deck height then the .030 is perfect!
I usually do an initial "mock" assembly after the boring is finished to check deck height (on both #1 and #4) before ordering the head gasket...
Only thing that is overkill for your build is the ARP main studs.
If your machine shop is good they can properly fit them. They really require main bore alignment checks and possible adjustment and many machine shops cannot handle this properly.
I agree with Six regarding the oil pump shims as well. Not needed for street car. Before I added the shims I'd chose the VVT pump (wider gears and more volume).
Both the .030 head gasket and the ARP main studs require a "wizard" for proper installation.
#8
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And don't buy anything from him. There have been quite a few of us who bought things from him and ended up with previously returned and or damaged parts. And he's really good at ducking people once he has their money.
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