sleeved block with a 86mm bored, want to go turbo, is this a good idea or no?

 

i thought 85mm was as far as you wanted to go so i will say no. if i am wrong, please explain why.

 

the walls get too thin for the high cylinder pressures a turbo creates. i actually wouldnt even go past 84mm.

 

my hommie is runnin a 86mm sleeved b16 block

 

anyone else?

 

bump, the sleeves are darton also

 

i wouldn't do it. 84mm is the biggest i would go for boosted application.

 

86mm is pushin it. you will proly have HG issues. i'm at 85mm and would rather be at 84mm but i had no choice to or resleeve. its been ok so far.

 

is 1.5mm really that much? compared to taking it to 84.5mm cuz that's what my other plan is

 

its not worth the few horsepower difference. just stick with 84mm so just incase anythign ever happens and you have to rebore it you can still go to 84.5

 

you dont want to crack a sleeve and rebuild again. Do it right the first time

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by The Tea-father &raquo;</TD></TR><TR><TD CLASS="quote">i wouldn't do it. 84mm is the biggest i would go for boosted application.</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93c1sol &raquo;</TD></TR><TR><TD CLASS="quote">is 1.5mm really that much? compared to taking it to 84.5mm cuz that's what my other plan is</TD></TR></TABLE>

man dont let these guy's scare you. you dont half to run insane boost numbers to make power.

displacement = power

yes thinner cylinder walls is something to worry about. but not as much as these guy's are makeing it out to be. here is a thought. why not run slightly higer compression ratio 9.8.1 - 10.5.1 something around there and just run a smaller turbo that will give you a longer power band and run lower boost pressures.

the motor is only as good as its tuning

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Importordomestic &raquo;</TD></TR><TR><TD CLASS="quote">

man dont let these guy's scare you. you dont half to run insane boost numbers to make power.

displacement = power

yes thinner cylinder walls is something to worry about. but not as much as these guy's are makeing it out to be. here is a thought. why not run slightly higer compression ratio 9.8.1 - 10.5.1 something around there and just run a smaller turbo that will give you a longer power band and run lower boost pressures.


Yeah, but the change in displacement is really small with that bore for the gain.. If it goes, you'll just be starting all over again.

the motor is only as good as its tuning
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yeah i know people are just saying its a bad idea for ***** and giggles. 86mm is for all motor cars. think about how thin the head gasket gets between the cylinder with that large of a bore, then think about how much pressure is in the cylinders. bottom line its not worth the extra 15 horsepower youll make, if your worried turn up the boost a pound.

 

I ran 86mm bore all motor for a year at a compression ratio over 14.1. I drove the car on the street frequently on 100 octane and never had a head gasket issue. EVER.

My point is that the motor had over 300psi cranking compression and massive cylinder pressure.

The thicker is easier to seal a head gasket part doesn't make sense to me. I will say that running an 86.5mm head gasket and indian head gasket sealer made my motor have far less problems than others running an 86mm bore and 86mm headgasket. There are peopel who even go 87mm on thier NA cars. I.E. RLZ. And no I am not mistaken it for an H-Series Block.

I say run the 86mm bore block, and run it hard. Just make sure you have true flat deck and head and you will be fine.

 

are you comparing cylinder pressures of a high comp all motor to a high boost turbo setup? big difference.

 

How big of a difference then are we talking about since you seem to know?

Of course it is a big difference. However, my 86mm sleeved block had the same amount of material surrounding the bore as my 81.5mm stock block. And we have seen what some people have done pushing the limits of stock sleeved blocks with FI.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Importordomestic &raquo;</TD></TR><TR><TD CLASS="quote">man dont let these guy's scare you. you dont half to run insane boost numbers to make power.
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Well you know.. actually you do need to run more boost to make power. Why build a thin sleeved motor to be stuck at 10psi when you could run a 84mm bore and run 40psi with room to rebuild *when* it needs to be rebuilt.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxmatt &raquo;</TD></TR><TR><TD CLASS="quote">

Well you know.. actually you do need to run more boost to make power. Why build a thin sleeved motor to be stuck at 10psi when you could run a 84mm bore and run 40psi with room to rebuild *when* it needs to be rebuilt.

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Becasue maybe his goals are to have a nice track car with great throttle response and 40 psi and 600+ horsepower do not interest him.

 

even more reason to leave a smaller bore so if something does happen he has room to rebuild. track cars get abused, abuse breaks ****. plain and simple.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxmatt &raquo;</TD></TR><TR><TD CLASS="quote">

Well you know.. actually you do need to run more boost to make power. Why build a thin sleeved motor to be stuck at 10psi when you could run a 84mm bore and run 40psi with room to rebuild *when* it needs to be rebuilt.

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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CoreyR &raquo;</TD></TR><TR><TD CLASS="quote">even more reason to leave a smaller bore so if something does happen he has room to rebuild. track cars get abused, abuse breaks ****. plain and simple.</TD></TR></TABLE>

He already has the 86mm block..... So if he breaks it he can resleeve it. Why ditch the block if it will work.

Everybody told me in the NA forum. No way will it work for what you want to do. 86mm bore is only for race cars. Blah, Blah, Blah, but everybody telling me that had zero first hand experience. So I tried it anyway and it worked out fine. B19Coupe also runs an 86mm block daily.

Have you ever even seen an 86mm block in person. There is far more material than what you think... Will it support 500+ hp. Maybe.... But maybe not as reliably as an 81-84mm block. At any rate, I from first hand experience, would feel comfortable with running an 86mm block and 10lbs from say a GT30R or T3/T04E something along those lines.

 

84.5mm; I'm betting that will be safe.

If you have trouble later you can re-bore to 85mm, so you're left with a backup which will most likely be ok too.

Beyond this...you should think about limiting the boost.

If all you want is 350whp, maybe 85.5mm is good eh.

 

well if he already has the block then might as well try it out.