|WYG|SS

i would like to bore my engine oversize but i got people telling me different things and just want to see what you guys have done.

if i bore it over and cause these engines are work horses will boring it over even do anything or just make me suck more gas?

what have you guys bored your engines over to and how much extra power have you seen? i know these engines wont see good power increases but just even a little bit extra will make me happy.

i have headman headers on my truck now and have seen a little increase in power and pulling power but im thinking i might go back to stock efi heads cause then i can have the egr hooked up and help me get better mpg. witht he headers i get 12.5 city and highway just in town but when i went mudding on laborday i had to go get parts from another town 40miles away for a friends mud truck and have gotten 16.5 mpg but that is all highway doing bout 60-63mph.. im just wondering if i bore it over if i can get good mpg again or just to stay stock and just get everything checked out. i also am thinking about putting a cam in and possibly the chebby 250 inline6 rockers on mine

djquik1

Have you done a compression test or a cylinder leak down test yet?
What maintenance have you done to the truck?

djquik1

Nevermind....Just saw your earlier post about last weekend.

When you take it apart, check the taper on the cylinder walls,if it is in spec Hone to specs and install new rings. I would only overbore if it needs it, and if that is the case go .030" over

|WYG|SS

how do you check the tapper? measue the inside if the cylinder on the top, middle, and bottom?

djquik1

In a sense,yes....They make a micrometer specifically for measuring cylinder taper....Check with the Snap On salesman....I don't know if Craftsman has one.

|WYG|SS

ok now i know what tool you are talking about. i tought i would use one of those caliper(i think they are called)measuring tools that i got, it only measures the inside and outside surfface. the one you are talking about is a round type meassuring tool that has like a little needle that extends on one side, right?

djquik1

You got it.

|WYG|SS

would this comp cam be good
http://www.summitracing.com/parts/CCA-66-248-4/.

how much more valve lift will this give me?

djquik1

I would not put a cam in it unless you are going to swap heads for an older style head from a 240 from the 70's.

The FI head is a fast burn design and does not react well to cams...about all you can do to them to them and keep them efficient is bronze valve guides and stainless replacement valves with 30 degree back cut and swirl polish.

You could port match the lower intake to the head as well.