raising compression
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I think its been said before that the 1.9 HO dome top pistons will hit the stock 1.9 SEFI head if used together. Getting the C/R around 11 is going to require more than a parts combination from several engines. It will require at least some custom machine work. The 1.9 SEFI is supposedly a vary poor flowing engine to begin with so its almost easier to swap to the better flowing SPI than it is to make the 1.9 flow better.
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Look at what 97dragscort(Matt) did with his 2.0L for N/A ideas.
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If you want to keep the 1.9 SEFI, it's not difficult to get to 11:1 compression, although you would need to get the block bored 1mm over, have the head milled, maybe some block decking, and use a 1.6L head gasket...or go with a thin copper gasket if you want to play with O-rings.
That said, the SEFI is one of the weakest US CVH engines, with the 1.6L carb series being weaker. IF you want more performance, then go for an SPI, as it'll be easier. Or else go with forced induction.
That said, the SEFI is one of the weakest US CVH engines, with the 1.6L carb series being weaker. IF you want more performance, then go for an SPI, as it'll be easier. Or else go with forced induction.
They won't fit in the 1.9 block unless you bore it out, which is stupid to do when you can just get a 2.0 block with pistons from the junkyard. I also remember someone saying the SPI pistons will hit the 1.9 head if they are used together.juggalo said:
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i'm not tryin to do a whole engine swap. i need the right set of tools and the money to do so which i don't really have. i've read that i could swap a 1.9 HO head but will lower the c/r if my origional pistons were used. it almost sounds like the same set up im doin on my honda. SI head with mpfi and a stronger camshaft, 2 layer hg, and dome top pistons.
Also, the HO head doesn't have a place for the cam sensor and there will be hole where the distributor used to be. Basically, what we are trying to tell you is you aren't going to get 11:1 without removing the engine. Like UnexplodedCow said, block decking and boring. Two major thing you would have to take the engine to a shop to have done. Not to mention if you shave too much off it will mess up the timing.
If you have the tools to do a head swap, pistons, and cam on your CRX then all you would need to do a motor swap would be an engine lift, about $100 at Harbor Freight.
If you have the tools to do a head swap, pistons, and cam on your CRX then all you would need to do a motor swap would be an engine lift, about $100 at Harbor Freight.
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I can attest to the timing being a problem with a milled head; I live with it daily. The biggest way to fix that issue is to use a Tempo flywheel, which has timing marks on it.
He could swap on a 1.6L head, which is basically the same as an HO, with slightly smaller intake ports, larger exhaust ports, and a hole for the cam pickup, but the wrong journals for the cam. However, the carb 1.6 cam could be used since it has a fuel pump lobe that could be reshaped for timing purposes....still, it requires machine work.
On a limited budget, you won't be able to do what you're thinking of.
He could swap on a 1.6L head, which is basically the same as an HO, with slightly smaller intake ports, larger exhaust ports, and a hole for the cam pickup, but the wrong journals for the cam. However, the carb 1.6 cam could be used since it has a fuel pump lobe that could be reshaped for timing purposes....still, it requires machine work.
On a limited budget, you won't be able to do what you're thinking of.
Regarding the milled head ... is there any data to tell (or guess) how much the cam timing is affected in relation to the milling ... say .020 and .040?
Are we talking about the cam timing being changed 1 degree - 5 -?
Is the timing advanced or retarded with the milled head?
I am curious if this was one of my issues with the original head that ate the lifters.
Are we talking about the cam timing being changed 1 degree - 5 -?
Is the timing advanced or retarded with the milled head?
I am curious if this was one of my issues with the original head that ate the lifters.
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Milling .040" would result probably around 4 degrees of retardation, about half a tooth off. And yeah, that's a pain to time, and the engine really has to wait until the belt is stretched for timing to be proper.
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You'll be sorely disappointed with porting that head unless you reshape the combustion chamber, install larger valve seats and valves, as well as port/gasket match the intake and exhaust ports. Also; that won't be cheap.
Won't you loose C/R if you reshape the combustion chambers?
Good luck getting a CPS trigger on the HO cam. It has to be welded on in exactly the same place as it is on the stock cam, otherwise it will throw your fuel injection off.
Good luck getting a CPS trigger on the HO cam. It has to be welded on in exactly the same place as it is on the stock cam, otherwise it will throw your fuel injection off.
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would this build up be legit?
http://escortfocus.com/html/1991-96_escort.html
it's for the 91-96 escorts with the sefi motor. i wanna do this but not too sure if escortfocus.com is the site where i wanna get my parts.
http://escortfocus.com/html/1991-96_escort.html
it's for the 91-96 escorts with the sefi motor. i wanna do this but not too sure if escortfocus.com is the site where i wanna get my parts.
That write up is a crock of chit ... let's see the dyno charts to back it up.juggalo said:
Most all of the stuff spouted by that outfit is grossly exaggerated ... like 14 Hp from the UDP ...LOL.
Save you $$ and be happy with what you have until you can put an engine in it and do it right or a turbo like Jeff said. Or, waste your $$ and end up with nothing.
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You lose compression, and then go for the dome topped pistons to compensate. It would be converting it to a hemi instead of leanburn.
I wasn't talking about the HO cam specifically. The 1.6 carb cam fuel pump lobe can be reshaped...it would work
I wasn't talking about the HO cam specifically. The 1.6 carb cam fuel pump lobe can be reshaped...it would work
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If you stick with 2nd gen SEFI you would need 1: the hole drilled in a 1st gen HO head running a 2nd or 3rd gen cam, or 2: a 1.6L with a modified fuel pump lobe on the cam. There is little difference between a 1.6L carb, EFI or 1.9L EFI-HO head in terms of fitment on the block. Also, none of this would be cheap, and you would be far better off going with a turbo. Even a VJ-11 would provide better power than going high compression. Also, if you want to technically argue the point 
going with forced induction does raise the compression, although the static compression ratio is typically lower than naturally aspirated.
going with forced induction does raise the compression, although the static compression ratio is typically lower than naturally aspirated.1 - 20 of 70 Posts
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