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Old 04-13-2001, 11:06 AM   #1
Jgrahn555
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06

Post High Compression

I don't own an SVX, but i'm wondering if any of you have upped the compression on your 6 cyls. What method did you use to do it?

Thanks in advance.

Jason
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Old 04-13-2001, 11:36 AM   #2
kastle
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I haven't done so, but I imagine that you could do it with new pistons....
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Old 04-13-2001, 02:30 PM   #3
CRZ_MSL
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That is exactly what I am talking about. Right now there is X distance between the maximum reach of the piston and the maximum reach of the valves. Increasing compression ration requires an increase in how close the piston gets to the valves. If it gets close enough, it becomes an interference.

This is not a bad thing, as long as your timing belt does not break. I think all Honda engines are interference.
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Old 04-14-2001, 12:32 AM   #4
CRZ_MSL
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I don't know of anyone who has taken apart thier EG33 (SVX engine). I would imagine that if you were to do this it would be byu swapping out the pistons.

The EG33 is a non-interference design. Upping the CR too much will change that.
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Old 04-14-2001, 12:54 AM   #5
Jgrahn555
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>>>The EG33 is a non-interference design. Upping the CR too much will change that.<<<

This I've never heard of happening on any non-interference engine ('course, i haven't heard all that much to begin with).

How does upping the compression ratio too much make it an interference engine? are you talking about valves hitting the piston or valves hitting valves?

Are there any books concentrating on high compression? Any web pages devoted to it?

Thanks again.

Jason
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Old 04-14-2001, 10:59 AM   #6
Blindeye_03
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I have never even seen an svx before...
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Old 04-14-2001, 11:08 AM   #7
MrHorspwer
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Post

Most engines right now are non-free spin, or interferance, motors. If you break a timing belt or chain, you have a bunch of bent valves or, worse yet, ventilated pistons. The easiest way I would think to raise the CR is to resurface the heads. I don't think many people have done this so you'd have to be very carful with valve to piston clearence. I'm not familiar with how the tension is kept on the timing belt so you'd have to keep into consideration not to take too much material off and lose tension and change the cam timing.
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Old 04-16-2001, 12:31 AM   #8
Jgrahn555
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>>The easiest way I would think to raise the CR is to resurface the heads. <<

I thought about doing this, but in the subaru, if you mill the heads down to much, the intake manifold won't fit. In all my research, i'm thinking that the only way to up comression safely is by new conrods and pistons.. Any other ideas?
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