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Main Crank Cap Help ? Best Option


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#1 sovenmini

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Posted 27 October 2020 - 07:07 PM

Hi I’m not new to building engines but never done a turbo engine before, so after some advise of the main crank cap, I have a turbo engine block with new 15cc pistons ect and hopefully by the end of the build my aim is for 140 to 170 BHP (fingers crossed) but as I’m looking for a high figure from a a-series engine what is the best / strongest option for the main crank cap ? I have a bog standard one at the moment witch I know will need a good quality strap adding to it or would it be a better option to add a new set of caps but the middle being upgraded to a 4 bolt system instead ? I know 4 bolt caps are mainly for high rev engines but was wondering if turbo engines benefit from this because of the torque increase ? I know lots of works is need for this because of in line boring ect but if it makes the engine stronger I’m happy to spend the money or is this no better than having a strap fitted ?

Any help would be great, many thanks

Edited by sovenmini, 27 October 2020 - 07:09 PM.


#2 mini13

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Posted 27 October 2020 - 09:19 PM

The standard cap is fine for your build, you'll only need to upgrade if your building a really screamer.

One thing I would suggest though, is using the swifttune billet beating cap dowels, as the old ones can be loose, the billet ones are nice and snug and will make sure everything is aligned

#3 REDICE

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Posted 29 November 2020 - 12:58 AM

If you want best and strongest and dont mind spending get a 4 bolt.

 

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#4 nicklouse

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Posted 29 November 2020 - 01:28 AM

Ran a strapped center cap to 8.5/9k with no issues.  Ow changed to the MED caps. For your build I would say not really needed.



#5 Steve220

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Posted 29 November 2020 - 10:34 AM

Hi I’m not new to building engines but never done a turbo engine before, so after some advise of the main crank cap, I have a turbo engine block with new 15cc pistons ect and hopefully by the end of the build my aim is for 140 to 170 BHP (fingers crossed) but as I’m looking for a high figure from a a-series engine what is the best / strongest option for the main crank cap ? I have a bog standard one at the moment witch I know will need a good quality strap adding to it or would it be a better option to add a new set of caps but the middle being upgraded to a 4 bolt system instead ? I know 4 bolt caps are mainly for high rev engines but was wondering if turbo engines benefit from this because of the torque increase ? I know lots of works is need for this because of in line boring ect but if it makes the engine stronger I’m happy to spend the money or is this no better than having a strap fitted ?

Any help would be great, many thanks


You don't need one, turbo engines don't need to rev. I put an MED centre strap in for insurance, but again, it isn't really needed.




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