Block posting- anyone done it

[BlitZ]

Anyone done it..
looks quiet simple and makes sense.. especially with b20

care to share the experience:thumbsup:

[pornstar]

yes and a many b20 powered touring cars run a method similar to posting. In fact the last generation of mugen b20a uses a similar method

[BlitZ]

yes and a many b20 powered touring cars run a method similar to posting. In fact the last generation of mugen b20a uses a similar method

it seems so simple....... hoping to do it with my next build...

People seem to do it to mainly race cars.. any con's for having it on street cars... like coolant leaks, warping sleeves etcetc

[bennjamin]

it seems so simple....... hoping to do it with my next build...

People seem to do it to mainly race cars.. any con's for having it on street cars... like coolant leaks, warping sleeves etcetc

its made to prevent sleeve warping :eek:

refer to this thread for a B20 build up and abit of info on posting

http://www.theoldone.com/articles/badtothebone/

[BlitZ]

its made to prevent sleeve warping :eek:

refer to this thread for a B20 build up and abit of info on posting

http://www.theoldone.com/articles/badtothebone/


it will be fine on a race car where it will be built, dynoed and almost raced immediately but for a motor which will see 150,000kms would it be fine..

Its more of a question of would the force of the thread to sleeve change over time (100,000kms)..

would i start gettting clearence on it after 30,000kms.. (then it would be worthless) or could it expand and warp a sleeve

[weeman]

what is block posting

[EfiOz]

Yes, we used to do it on the B20A based MF204B Formula 3 engines. We tried two ways, one was welding around the top of the bore to the outer block casting and the other was drilling and tapping down between the sleeve and block casting, then inserting an aluminum bolt and machining it all flat.

Worked great for high comp atmo engines running coolish temps (F3 ran 16:1 and at 55C from memory) but I don't know how round the bore would be under big boost and high temps.

[ginganggooly]

Anyone done it..
looks quiet simple and makes sense.. especially with b20

care to share the experience:thumbsup:

i was talking to dynodave about this a while back, he didn't seem to like the idea -citing heat spots as an issue.

[pwr2w8]

block posting has been done for many years, heavliy used in nascar.
i have done it with no drama's, its way better than block gauard, and advise dynodave that you dont get heat spots, if he hasnt ever done it he wont know. my 2 cents

[Slow96GSR]

what is block posting

Endyn's product description: http://www.theoldone.com/components/Posts/endyn_block_post_kits.htm

Googled: http://www.homemadeturbo.com/tech_projects/block_posting/

http://www.muller.net/sonny/crx/engine/posted.html

Enjoy!

[ginganggooly]

block posting has been done for many years, heavliy used in nascar.
i have done it with no drama's, its way better than block gauard, and advise dynodave that you dont get heat spots, if he hasnt ever done it he wont know. my 2 cents

So, what your saying is that whatever works on a Nascar V8, is automatically going to work on a b-series I4?

[Waggy]

There are always people in the industry that swear by it, and those who wont touch it with a 40ft pole.


True, and same can be said about block guards.

Even proof is sometimes confusing with some guys running 20psi through a block guarded block all day long and beating on their cars for 100,000kms+ with no probs - and then you got the guys who are running a mild tuned N/A setup that blame their engine failure on the block guard....

I really think that - like block guards - posting is something that you gotta do right in order for it to work correctly and not screw your block.

[Slow96GSR]

As long as the posts are the same material they will expand at the same rate. The bad part is that when the cylinders expand you'll start to force them to be out of round. This is bad. The outter block walls aren't really an issue. They don't expand as much or as fast as the cylinders. I don't nor would I use posts over sleeves, or even a block guard. I still wouldn't use a block guard, but that's just my opinion.

[EfiOz]

EfiOZ maybe you can enlighten me. The problem I have with posts is this you are dealing with three metal expansion points. First you have the cylinder walls & sleeves, the posts, and then the other walls of the block to deal with. As we all should remember from physics classes when metal is heated it has to expand.

So lets start with the cylinders (and sleeves) if they have posts poking them on just two sides and they start to expand wouldn't the cylinder have more resistance to expanding at the post sites and therefore the unsupported sides would be able to expand easier making the cylinders go oval shape not round? And how could you check with the head on if this is happening?

Next you have the posts themselves from the physics classes again we know long objects like the post bolts expand longitudinally (down the long length not getting thicker) and since the cylinder gets hotter quicker it then expands out toward the post bolts but at the same time the bolts are getting longer putting more force toward the cylinder as they warm up so I would think you would be getting differing forces on the cylinders as they and the posts heat up at different rates and therefore expand at different rates as the cylinders are being heated by direct contact with combustion forces while the posts are just being heated by the coolant so I would think there would never be constant measurable force being directed at the cylinders because of the different rates of expansion and again how could you measure it with the head on?

And finally the outer block walls that the posts are screwed into. As they are the furthest from combustion heat they should expand the slowest of all three components. But the problem is the posts are screwed directly into this surface so while the the cylinders and posts are getting heated faster the block is getting less heat and expanding less slowly so again the forces being put onto the cylinders are being increased when the block is warming because the cylinders and posts are expanding quicker than the block walls but then when the block is fully heated it expands outward making the forces less because the screwed in posts are moving with the block outward making the force less.

So the bottom line is how do you work with/control the differing expansion rates of the three major components?

Until someone can explain how they solved the problem I'd vote against posting.

True, hence my advice against using it in a turbo app. My post answers your questions already. We ran NA (although big CR) and almost cold coolant temps.

[EfiOz]

We used aluminum bolts for the expansion problem. If you use stainless or a denser metal with different expansion properties you get issues with them loosening and tightening as well as corrosion (unless it's a good grade of SS).

[BlitZ]

We used aluminum bolts for the expansion problem. If you use stainless or a denser metal with different expansion properties you get issues with them loosening and tightening as well as corrosion (unless it's a good grade of SS).

yes and from my understanding, endyn makes the post bolts/thread out of the same material as honda manufactuers there blocks

[BlitZ]

EfiOZ maybe you can enlighten me. The problem I have with posts is this you are dealing with three metal expansion points. First you have the cylinder walls & sleeves, the posts, and then the other walls of the block to deal with. As we all should remember from physics classes when metal is heated it has to expand.

So lets start with the cylinders (and sleeves) if they have posts poking them on just two sides and they start to expand wouldn't the cylinder have more resistance to expanding at the post sites and therefore the unsupported sides would be able to expand easier making the cylinders go oval shape not round? And how could you check with the head on if this is happening?

Next you have the posts themselves from the physics classes again we know long objects like the post bolts expand longitudinally (down the long length not getting thicker) and since the cylinder gets hotter quicker it then expands out toward the post bolts but at the same time the bolts are getting longer putting more force toward the cylinder as they warm up so I would think you would be getting differing forces on the cylinders as they and the posts heat up at different rates and therefore expand at different rates as the cylinders are being heated by direct contact with combustion forces while the posts are just being heated by the coolant so I would think there would never be constant measurable force being directed at the cylinders because of the different rates of expansion and again how could you measure it with the head on?

And finally the outer block walls that the posts are screwed into. As they are the furthest from combustion heat they should expand the slowest of all three components. But the problem is the posts are screwed directly into this surface so while the the cylinders and posts are getting heated faster the block is getting less heat and expanding less slowly so again the forces being put onto the cylinders are being increased when the block is warming because the cylinders and posts are expanding quicker than the block walls but then when the block is fully heated it expands outward making the forces less because the screwed in posts are moving with the block outward making the force less.

So the bottom line is how do you work with/control the differing expansion rates of the three major components?

Until someone can explain how they solved the problem I'd vote against posting.

:thumbsup: :thumbsup: similar ot what i was thinking, but into more depth...

[EfiOz]

Thanks, EfiOZ didn't realize you were running cold coolant temps. Any hints on how you guys figured out they were loosening and tightening when you can't see inside the block with the heads on.

When you strip them down you can see that they've moved from their depth. Welding was a better but much more time consuming and difficuly option. We just placed aluminum rods instead of bolts and welded them in place.

I'll take a pick of a flogged out block and post it later. It'll have to wait until Tuesday. I'm off to Adelaide in the morning.

[ALLMTR996]

i was talking to dynodave about this a while back, he didn't seem to like the idea -citing heat spots as an issue.
Not heat spots he said pressure spots where the post sits on the outa sleeve,and has seen what it does to a bore/pistons after an engine ran a little hot.
ALLMTR996

[TODA AU]

:rolleyes: Really...
Funny you say that... :p

[tinkerbell]

Blitz, FWIW - i have not 'posted' my B20B and it seems fine after 20'000km...

mind you , i have no idea what to be looking for!

anyone know what to look for when determining if a block needs to be 'posted'?

http://home.exetel.com.au/tinkerbell/b20vtec/b20baug06.jpg

[tinkerbell]

I'd install new sleeves.


exactly the answer if you are concerned about sleeve integrty!! :thumbsup:

[BlitZ]

wah piston head looks so clean.

..
Yeah ... ive read amillion and 1 of your posts tink... basically compression cracks the b20s.. if rod and head bolts are upgraded and running close to std comp, it will last forever...

..

Not really referring to b20 specifically.. but am wondering the pros and con's of a poor mans reinforcement, posting.. ;)

[tinkerbell]

and those are re-cut valve reliefs too...

[tinkerbell]

thanks for your interest, i will check my pictures at home, i will send you a PM about this with more pics,

oh, and no - i dont index my plugs...