Okay we were looking at blocks to sleeve....and my builder had an H22A4 block sitting there. He wants to sleeve it because of the condition of the motor itself (Brand new!) and the larger crank main journals (stronger!) and the cast oil pan.
Anyways we're sleeving it to go to 89mm. I saw some companies like GE put these tabs or spacers between the sleeves and and the block to keep them from moving. Is this necessary for an NA application? Is it mostly for boost?
Are you talking about the studs that go into the block to help stablize the cylinder? It's not essential per say... It's a block guard that retains good cooling. I'd say that in a high RPM motor some fashion of a block guard is essential.
I was poking around endyn's site last night and Larry used studs (i think he called them posts) to stabilize the open deck on his NA B20/VTEC engine build up.
__________________ Paul
2009 Mazdaspeed3 | 1995 Miata | 1999 Crystal Blue Base - bought 6/13/02, sold 3/11/09
Yeah, posts are the way to go. They stabilize the sleeve while maintaining the best cooling properties. Im doing this for my block with GE sleeves. Get a price quote from Larry on his simple block mods.
This is primarily for high-CR or high boost applications where cylinder pressures are high. It helps prevent the cylinders from "walking."
Any form of stabilization would be "better" and I think as mentioned it would be a good idea. Depending on who you go with for sleeving you could have this done at no extra cost and I would recommend it if you are in the process and boring over. Without boring over I think that the thicker wall (like with Darton) helps stabilize everything.
if you go to closed deck, you'll lose some cooling capacity in the head, and won't have as much detonation protection with that high cr you were looking at.
What Larry did? Not sure. I know from V8's what he used to do, I assume it's the same.
If you haven't seen a block guard or "fingered" sleeves, they essentially end up looking like the difference between and open and closed deck. It accomplishes the same thing, closing off the top structurally for strength but still allowing coolant to flow.
And this is the posting the Larry uses.. These pics are taken from his 2L monster engine. Though they don't depict the posting all that well. But you can see it.
What is the longevity of sleeving without posts and sleeving with posts? I mean are the cylinders gonna walk for sure if you don't?
__________________
04 Ford Powestroke Diesel Crew Cab, Shortbed,4x4, SCT Tuner,with Tunes from innovative Diesel,4 inch Donahoe lift,ARP headstuds,AFE Stage 2 intake,MBRP 4 inch Exhaust,4:30 gears from unitrax,18 inch KMC wheels(black) with 35 inch Toyo M/T's.
440 whp 800 torque.
no they're not that know of...like I don't plan on boosting, and if I did I would weld in some sort of block guard later I guess, since I would be changing the pistons anyway.
I don't see a lot of evidence of it. Actually I'm gonna move this to Forced induction to see what they have to say.
If you haven't seen a block guard or "fingered" sleeves, they essentially end up looking like the difference between and open and closed deck. It accomplishes the same thing, closing off the top structurally for strength but still allowing coolant to flow.
Sleeves that have built in block guards do have holes to pass coolant through, but still dont offer anywhere near as much cooling as a fully open cylinder does. There is still alot of metal blocking off the most important part of the sleeve which is the area at TDC. THis is what needs to be cooled most effectively. ALL block guards and top braced sleeves hinder cooling at TDC. Get a basic Iron sleeve and post the block, best of both worlds.
Basically you want cooling to be maximum at TDC which makes sense, this is where the combustion explosion occurs. Hindering this makes tuning harder and the car will be prone to detonation at CR higher than 11:1.
Sleeving may make some sense when your at over 40lbs of boost and your CR is probably going to be pretty low to begin with, but with an NA car with say a very large dual stage nitrous shot, its going to be a waste and hurt your performance/tuning capabilities. Design the engine around your needs, best method.
That's not true. Tabs like the GE sleeves or even a Tee top closed deck give more surface area for thermal transfer to the coolant. They also allow an easy thermal pathway to the outside of the block.
Hehe..."combustion explosion".
__________________ DirtyLude
Mark Higgins
Toronto Prelude Club www.hondaprelude.to
Yes open sleeves are the way to go, but I am having my cylinders posted too, but to make sure we are on the same page, the posts arent located at the top of the cylinder. they are located about in the middle, where cooling wont be affected and rigidity is increased.
Quote:
That's not true. Tabs like the GE sleeves or even a Tee top closed deck give more surface area for thermal transfer to the coolant. They also allow an easy thermal pathway to the outside of the block.
Open sleeves have much greater cooling and heat transfer when liquid cooled. Using the block as a natural heatsink with "T" style sleeves only hinders cooling properties. Heat transfer is only hindered.
Why was this post moved to forced induction btw? Some moderator not capable of reading the title? NA means Naturally aspirated applications.
Originally posted by Ritteri
Why was this post moved to forced induction btw? Some moderator not capable of reading the title? NA means Naturally aspirated applications.
Yes this moderator knows how to read. I moved it here because FI guys have more experience sleeving these blocks...I'll move it back in a little bit
I stated in a post above but you didn't read it obviously
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