hey I was wondering if I should bore my motor over when I order new fordge pistons or not...all my compression is 210 and 209 between all 4 cylinders...cause I can get a deal right now just on 75mm bore srp pistons or i can get cp pistons 75.5mm....any suggestions?

 

When ever you redo the pistons and rods, we always suggest a fresh bore and hone, as well as micropolishing the crank if its a pretty old motor.

The purpose of a fresh bore and hone is to ensure that the cylinder walls are nice and smooth. Sometimes you get cylinders that are a bit warped or worn out after so many miles on them due to regular wear and tear.

When you are putting in new pistons, they are machined to the exact dimensions and you should bore the cylinder walls to accept the clearances that is required.
Your machine shop should also be awake of the specs of the pistons you are putting in. Each piston brand will have their own Clearance requirements for the piston they make.

I know some people just pop in the new pistons without doing any machining at all, thats on them. but if you really want to do it right and last long, I'd do the fresh bore and hone on the block before you put it back togehter.

 

oh and i'd get the 75.5mm rather than the 75mm, especially if you are going to do the bore and hone.

 

My engine's pretty boring too

 

thanks for response I was checking out your sleeve blocks but I just dont got that kind of cash wish I knew someone selling a D series sleeved block for a good price...

 

LOL i read that as a BORING engine I.E. not fast

 

thanks for checking out our site. Its still a work in progress. We will have Articles on Single cam stuff and K and b series builds pretty soon, so check that out.

But ya doing a serious built engine costs money, but you have to keep in mind that these are quality parts we use and we never skimp on using parts that are not proven.
someday you can get a bomb *** block too. In the meantime, have fun with what you have. Just remember that if possible try to do it right the first time rather than skimp out on things just to save some money. In the long run, it comes out better and worth your money. trust me man, i learned my lesson when i was new to the scene back in early 90s. hehe

 

ya man...only thing I am going cheap on is using stock sleeves...for any sleeve block its gonna run around 1g and that dont fit my d16 turbo budget...full-race show a good example of stock sleeve supporting power but how long that will last who knows lol...but I dont plan on boosting that extreme really

 

ive read/heard through honda tech that boring and honing is not neccesary on a lot of honda engines if you are doing a stock rebuild. i cant say i have rebuilt any honda engines, but the justification i have read for this is that honda's specs from the factory are so much tighter than what 99% of the machine shops anywhere can reproduce, and that its just better to leave it alone if you are doing a stock rebuild.

can anyone comment on this idea? i keep reading conflicting stories, and i have seen pics in a thread where a guy pulled a d16a6 that had 2xx,xxx miles on it and you could still see a little of the factory cross hatching on the cylinder walls.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sanimalp &raquo;</TD></TR><TR><TD CLASS="quote">ive read/heard through honda tech that boring and honing is not neccesary on a lot of honda engines if you are doing a stock rebuild. i cant say i have rebuilt any honda engines, but the justification i have read for this is that honda's specs from the factory are so much tighter than what 99% of the machine shops anywhere can reproduce, and that its just better to leave it alone if you are doing a stock rebuild.

can anyone comment on this idea? i keep reading conflicting stories, and i have seen pics in a thread where a guy pulled a d16a6 that had 2xx,xxx miles on it and you could still see a little of the factory cross hatching on the cylinder walls. </TD></TR></TABLE>

You can get lucky and pull out that motor with everything still in great condition.
But really, you have to think that wear and tear will most likely be the best conditions for jus dropping in a new piston. Especially a forged piston.

Coming from a company that Tears down Many motors to get rebuilt. We've seen good motors that are still in great condition, and you get your share of crazy worn out ones. But every single engine that we do is totally refreshed with a new bore and hone. No one wants to spend money on pistons and rods and Take that chance in not prepping the block for a good hone.

as far as honda specs being 99% better than any machien shops can do. I disagree with that idea. While all machine shops are not the same, you have your Top Notch ones that have the best equipment and precise tools to be able to do a good machining on your block. You just have to go to the right places that have high standards in what they do.

I guess its kinda like a cheap paintjob. you can take your car to a place and have them just paint the car as is, as you brought it in, dirt and all on the body. Or you can have the body shop prep it before painting it by cleaning and taking out blemishes on the body.

 

I was taught to bore .040 over on any engine rebuild..Ensures a true circle..