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Old 01-23-2012, 02:56 AM   #1
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Default Building a high cr n/a engine. Need opinions

I know this is a turbo forum but I have come across some n/a builds.
I am about to build my 95 1.8L, it will be used for autocross and track days. Will use regular gas
I have some questions (look next to "my plans")
My plans are the following:
-MS3 for ecu
-bp 1.8L bottom end.
-99-2000 head with some minor porting, gasket match bla bla.
-Racing beat header (do I need a 99-2000 header or do I use the 94-97? I know the intake ports are different, what about the exhaust ports?)
-99-2005 square top intake mani
-SCAT rods
-stock or 11.1cr supertech pistons. Most likely stock (now here is my question. Emilio's car has a 2001 bottom end and he is using a 99 head shaved .015", I read that the 99 head has a larger combustion chamber than a 94-97 head and milling it a bit is needed to achieve same cr as a 94-97. If I use the 11.1cr supertech pistons should I mill it to keep the 11.1cr? or should I leave it alone. If I use the stock 9.5cr pistons how much can I safely mill the head to raise compression without starting to knock on regular gas or hitting valves? -maybe .020-.030"? has anyone done this?)
-Mazdaspeed intake camshaft
-will need adjustable cam gears if I mill the head. Are the OBX ones decent?
-Injectors. Will stock freshly cleaned injectors suffice?
-coolant reroute.
-ACL bearings, studs.
-Boundary engineering oil pump gears, does anyone else make them? (I wonder how high I could rev this engine with the mods I plan and still make power) Maybe I can go with stock oil pump?
-Oil cooler, probably home made.
-1.6 act HD organic clutch, cusco 10lb flywheel.

Ok those are my plans/questions. I tried to search for all the answers and those are the one I couldnt find. Thanks

Any ideas, opinions will be appreciated

Last edited by btabor; 01-23-2012 at 03:07 AM. Reason: added more details
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Old 01-23-2012, 06:30 AM   #2
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Why not start with a VVT engine instead?

Sure, there are much less options for cams (no intake blanks available at the moment) but you start at a slightly higher CR and have the potential to spread the torque curve a bit.

I have ST 84mm 11:1 pistons going into my build and will see what the final CR will be after decking (pistons flush with block, stretch in the 0.8mm gasket) etc. My comb cambers became 52cc after some unshrouding.

The exhaust ports are the same for all BPs, so you can use your old header.
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Old 01-23-2012, 09:04 AM   #3
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Easier solution: Buy a k20(comes stock with more power than you could get out of any Built BP on 93) and just focus on the fab work. Win.
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Old 01-23-2012, 09:59 AM   #4
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I think if you buy the pistons for 99-up and they will likely compensate for the head differences.

You want to run 11:1 on pump gas? I don't think you will get as much timing advance without detonation on 92-93 octane as you might need for peak torque.

You asked about revving high but didn't include an ATI damper. I would, especially with a lightweight flywheel.

Boundary is the only reasonable place for the good OP gears.

You forgot shim-under-bucket lifters. If you are planning to rev high you will want them to reduce valvetrain weight.

You will want adjustable cam gears even if you don't mill the head, just to dial in power on the dyno.

I'm not a big fan of milling heads unless they are out of true. They can be more prone to warpage as the metal sealing surface thins out. And if you bother to do porting, you may need the head not to be out of chances to mill for true in the future. You don't want to have to buy a new head the first time you have a problem. Same with the block.

Also invest in a 53mm radiator if you haven't already.
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Old 01-23-2012, 10:23 AM   #5
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Originally Posted by sixshooter View Post
You asked about revving high but didn't include an ATI damper. I would, especially with a lightweight flywheel.
Sound logic if you will spend the most of the time free revving.
From the crank perspective the clutch will hold it firmly to the drive-train and the crank pulley will be the loose end (and the rods puts their momentum on it in between these points). The weight of the flywheel is only noticeable in the cases where it's weight is a noticeable inertia of everything connected to it (i.e. clutch engaged or very low gear).
So I would say that the weight of the flywheel have very little to do with the dampening of the torsional vibrations in the crank (which get worst at the front, oil pump)

But ATI damper and improved Oil gears are on my list (but not ordered)...

As soon as you pop any engine open, the drainage of cash starts (so will a K20 if it's not perfect from the start).
I'd be surprised if the whole gasket/sealing/sealant-kit for a BP goes for under $1k (at least it feels that way, especially if you add 5-6 shipments since you always forget some small thingy).
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Old 01-23-2012, 10:31 AM   #6
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Quote:
Originally Posted by NiklasFalk View Post
As soon as you pop any engine open, the drainage of cash starts (so will a K20 if it's not perfect from the start).
I'd be surprised if the whole gasket/sealing/sealant-kit for a BP goes for under $1k (at least it feels that way, especially if you add 5-6 shipments since you always forget some small thingy).
You dont need to open a k20..... With a RBC intake mani, header, and cam with engine managment you can put down 250+ whp

Completely stock with a decent intake and catless exhaust will put down 200+ whp
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Old 01-23-2012, 10:50 AM   #7
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Quote:
Originally Posted by Boost Joose View Post
Completely stock with a decent intake and catless exhaust will put down 200+ whp
...and 140wtq. Still, I'd probably rather have the S2k engine in my car thatn what I have now. Then again...no, I wouldn't.
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Old 01-23-2012, 11:22 AM   #8
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Quote:
Originally Posted by Boost Joose View Post
You dont need to open a k20..... With a RBC intake mani, header, and cam with engine managment you can put down 250+ whp

Completely stock with a decent intake and catless exhaust will put down 200+ whp
So you will never need to open a K20...
I know Honda are building their engines well, but never needing a overhaul...

With the fabbing needed, who would not spend some time verifying the engine is sound, going beyond a leakdown. And while you're at it...

Fiddling with engines is never inexpensive, regardless which path you choose. And of course it's easier to choose a LSx if you want 400whp N/A. But you can always play with the BP a little until you want to man up and hunt for interesting gearbox options etc.

K20 is not a bad engine in any way, but it's not a baby step from a BP as a slightly modded BP is. The OP is worried about keeping the header...
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Old 01-23-2012, 11:30 AM   #9
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Quote:
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...and 140wtq. Still, I'd probably rather have the S2k engine in my car thatn what I have now. Then again...no, I wouldn't.
more like 160 wtq....either way pretty sad you can pull just as much power out of a bolt on 2 liter than you can with a moderatly boosted BP.
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Old 01-23-2012, 12:36 PM   #10
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Quote:
Originally Posted by NiklasFalk View Post
Fiddling with engines is never inexpensive, regardless which path you choose. And of course it's easier to choose a LSx if you want 400whp N/A. But you can always play with the BP a little until you want to man up and hunt for interesting gearbox options etc.
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Old 01-23-2012, 12:41 PM   #11
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the noob is right though, (and its f20c not k20 btw), the honduhh engine bone stock will make much more power than a race prepped n/a BP.
It is a very involving and quite expensive swap though, so definitely not for everyone.

And no, it will not beat or keep up with a moderately boosted bp, unless your definition of moderate is 5psi. I fart more than 5psi
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Old 01-23-2012, 12:42 PM   #12
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No one pointed him to the hipster forum yet? They love high comp high revving low power ITB'ed motors
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Old 01-23-2012, 12:44 PM   #13
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well since he mentioned auto-x and track days and not hardparking and fellatios we're thinking he might not fit in there
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Old 01-23-2012, 12:46 PM   #14
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Quote:
Originally Posted by Boost Joose View Post
more like 160 wtq....either way pretty sad you can pull just as much power out of a bolt on 2 liter than you can with a moderatly boosted BP.
Yeah, I'm really jealous of any 4-door Honda sedan driving down the highway, driven by a mom, lol.
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Old 01-23-2012, 12:48 PM   #15
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either way, why run pump gas and not e85, it may not make as much sense for a N/A vs boosted motor but higher octane and less knock/dett may help? If the op can even get access to anyway. plus its cheaper than even 87
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Old 01-23-2012, 12:51 PM   #16
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Quote:
Originally Posted by Dparks7 View Post
either way, why run pump gas and not e85, it may not make as much sense for a N/A vs boosted motor but higher octane and less knock/dett may help? If the op can even get access to anyway. plus its cheaper than even 87
because its nowhere near as beneficial on n/a application (even with high cr) and will not make any more power or be significantly safer.
And yes it will be much more expensive because the car will still consume roughly 30% more of it vs pump gas.
On a high cr n/a application race gas is king.
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Old 01-23-2012, 12:58 PM   #17
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anyway from what I have read, and if I had the extra 700 bucks lying around why not shoot for carillo rods, they are lighter and will help the motor rev smoother. If he plans to use the 99-00 head why not try the exhintake cam swap instead of the mazdaspeed cam? unless that only works for the 94-97 head as thats all ive seen it used on
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Old 01-23-2012, 01:26 PM   #18
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Old 01-23-2012, 01:30 PM   #19
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so someone's made one rwd, cool.
even more work than an f20c
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Old 01-24-2012, 03:49 AM   #20
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I should have added in my first post that I am trying to build this engine on a relativelly low budget. I though about going VVT but that involves more $. Im ok with the SCAT rods because they are $250 instead of $750. Thats $500, I can almost get a MS with that difference.
And I know I said high CR but if I keep the stock pistons and I add the rods I could always turbo or supercharge in the future.
About the exhaust-intake swap. Do I just use an exhaust cam on the intake side too?
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