Anyone done it..
looks quiet simple and makes sense.. especially with b20
care to share the experience:thumbsup:
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Anyone done it..
looks quiet simple and makes sense.. especially with b20
care to share the experience:thumbsup:
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
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
what is block posting
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.
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
Endyn's product description: http://www.theoldone.com/components/..._post_kits.htm
Googled: http://www.homemadeturbo.com/tech_pr...block_posting/
http://www.muller.net/sonny/crx/engine/posted.html
Enjoy!
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.
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.
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).
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.
:rolleyes: Really...
Funny you say that... :p
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.../b20baug06.jpg
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.. ;)
and those are re-cut valve reliefs too...
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...