I'm new here & don't know that much about cars. I just bought a '66 Mustang that I am in the process of restoring but I would like to get some info on different things so I know just what I'm going to do to it & can plan my budget. Anywho, I was wondering about boring my 200 straight 6. It is at stock right now, which I believe is .30?? Correct me if I'm wrong. I was wondering how much I could bore it to & what all I would have to change to accomadate that boring. Any info would be great & thanks in advance, Q
200cid Boring
- Thread starter brnc_bstr87
- Start date
Without measuring the cylinders it would be difficult to determine if a block requires boring, and without knowing the mileage, or how it runs.
If you think that boring is a way to get more power, with these engines the effect would be negligible.
Stock is stock, 3.68", and an .030 overbore would be 3.71".
If you think that boring is a way to get more power, with these engines the effect would be negligible.
Stock is stock, 3.68", and an .030 overbore would be 3.71".
Welcome to the wonderful world of old cars!
A stock 200 had a bore of 3.68 inches. It used to be kinda standard to overbore most engines .030, which would leave a 200 with a new bore of 3.71 (3.68 + .03). If yours has never been rebuilt / bored, it should be right at 3.68 (plus whatever wear, which is almost never uniform - which is why you'd want to overbore).
Anyways, you'll really need to have the bores measured, then talk to your machinist if they need overboring, and how much. If they need overboring, then you'll have to replace the pistons/rings with new ones that match the new bore diameter.
EDIT: There is a ton of good reading on rebuilding / modifying at the Classic Inlines website's tech section. http://www.classicinlines.com/tech.asp#SmallSpecs
A stock 200 had a bore of 3.68 inches. It used to be kinda standard to overbore most engines .030, which would leave a 200 with a new bore of 3.71 (3.68 + .03). If yours has never been rebuilt / bored, it should be right at 3.68 (plus whatever wear, which is almost never uniform - which is why you'd want to overbore).
Anyways, you'll really need to have the bores measured, then talk to your machinist if they need overboring, and how much. If they need overboring, then you'll have to replace the pistons/rings with new ones that match the new bore diameter.
EDIT: There is a ton of good reading on rebuilding / modifying at the Classic Inlines website's tech section. http://www.classicinlines.com/tech.asp#SmallSpecs
Thanks for the info.! So, I guess whatever I do will be based on what the machine shop says then I guess. I appreciate your help. One more question, if I do bore it, will I gain any noticeable horesepower? If so, at what boring will I notice? Sorry for the nutty questions, but I hardly know anything about engines.
All by itself, you won't notice any difference in overboring, it'll only increase the total displacement by a couple of inches at most.
While you've got it all apart though, is a good time to think about maybe shaving the head to increase compression, switching to a larger camshaft, etc, etc, etc. Sometimes it's hard to know where to stop.
While you've got it all apart though, is a good time to think about maybe shaving the head to increase compression, switching to a larger camshaft, etc, etc, etc. Sometimes it's hard to know where to stop.
A few nights' worth of browsing this forum should give you an idea of what kind of modifications are common. Then you can start planning mods according to your application.
You will learn a lot just by browsing here. I know I have.
And you will get an informative and friendly answer to any question you may have. No matter how silly
You will learn a lot just by browsing here. I know I have.
And you will get an informative and friendly answer to any question you may have. No matter how silly
BaldvinE":1me4fver said:...And you will get an informative and friendly answer to any question you may have. No matter how silly
Case in point.
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