Track Tac

AKRA Clone Engine thoughts i.e. (billet rod, larger overbore)

Thanks guys! All good info here and PD replied in post #12. The same feelings as mine to this subject. As far as the post regarding only wanting the bore rule so it allows align boring blocks. These blocks are available if one has the sources like myself and many others, that there is enough material undersized to align bore it to std. bore. It had nothing to with that from my end. just to keep a block going longer due to bad maintenance and or used up bores. but none the less appreciate all of the responses.
Matt Field
DMD Performance
 
Concerning line bore. Remember back when the flatty would have a tell tail sign that the bore was out by the top edge of the cylinder. There would be a lip you could catch your finger nail on at one side of the cylinder and not the other. Why aren't we seeing that in the clone. So if there is no sign of mis alignment, what is the need for undersize blocks to bore to standard.
 
Don,
I do remember this. In general many blocks have a factory casted in sleeve. Briggs, clones etc. When done on a production line there is always variance without a doubt. Align boring just helps to ensure rotating assembly is all in line and on center of crankshaft. Helps with part wear and frees up engine from some stresses. Now.. is it necessary..? Not at all. Gains..? minimal.. I have built engines both align bored then honed, and also just honed as is to clearance I want and both have won races. MY main thoughts for the overbore being opened up is strictly to allow the racers to get a little longer use out of their blocks..
Regards,
Matt Field,
DMD Performance
 
I think this topic was discussed in length last year as well. Right now you can buy a new block for about $25 give or take a few bucks and it comes with a new bearing as well. How is changing the rules to allowing boring going to save the racers money? I can check but i dont think my local machine shop is going to line bore my old block for less than that.
 
silverback said:
My question is who has, is selling undersized blocks to allow align boring?
Jim
Click to expand...

http://www.racecityraceparts.com/clone-gx200-crankcase-block-under-size-bore-035/

just a quick search

If you are worried about buying a $40 block to save money and instead want to pay $50(cheapest in my area) to have a block bored then I think you are barking up the wrong tree. Bore them as big as you want, you are still fighting the same size carb which can barely keep up now on unrestricted motors. My opinion, .030 bore will not save any money. Billet rod, whichever way it goes doesn't matter to me. Many will still run stockers. People tend to forget that just because it is allowed doesn't mean it is required. jmo
 
I've checked a ton of blocks to see if bore was a true 90 to the crankshaft for concern over ring seal and drag, most clones are within .0002 to .0004 over the length of the bore. Other manufactures are normally .0008 to over .001 . I like the smaller bore because it'll fill faster on intake charge.
www.racingcarb.com
 
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