Bore Spacing

[epsilon2322]

Was wondering if I could get a link or info on bore spacing and bore sizing (length and width) of the 3.8L. To my understanding the 3.8L is pretty much a LT1 missing two cylinders so if thats is true than the bore spacing and size would be the same right? Thanks

[LETZRIDE]

Re: Bore Spacing

Is this what you need? http://engine.firebirdv6.com/ci.html

[epsilon2322]

Re: Bore Spacing

I'm not going to lie I'm still trying to learn here but um is that link showing the space in between the bores. Was going to make a custom itb setup. Need to know the location of the bores so i can get a custom mounting plate made. But if that link is what im looking for thanks but thanks anyways more info the merrier.

[flamingchicken]

Re: Bore Spacing

that link is showing the what cubic inches you would arrive at given an increase in x(bore) or y(stroke)

what are you trying to do exactly, elaborate.

[LETZRIDE]

Re: Bore Spacing

I'm not going to lie I'm still trying to learn here but um is that link showing the space in between the bores. Was going to make a custom itb setup. Need to know the location of the bores so i can get a custom mounting plate made. But if that link is what im looking for thanks but thanks anyways more info the merrier.

you dont need to know the location of the bores to make an ITB setup ...i know that because I have one designed and on paper at the moment... are you confusing this with something else possibly that you need to find out?

[flamingchicken]

Re: Bore Spacing

when i hear ITB it means individual throttle bodies...bore spacing should not be a factor. bore spacing is the amount of room between the cyls, measured from the center of each bore to the next, subtracting the diameter (R + R) to give you the space between the cyls.

[LETZRIDE]

Re: Bore Spacing

when i hear ITB it means individual throttle bodies...bore spacing should not be a factor. bore spacing is the amount of room between the cyls, measured from the center of each bore to the next, subtracting the diameter (R + R) to give you the space between the cyls.

exactly...unless he is confusing it with the head port spacing?...that you may need to know, depending on how you go about building your itb setup...there are many ways...but bore spacing does not play a roll in any of them...

[epsilon2322]

Re: Bore Spacing

head port spacing is what i'm looking for. I can see in my head but i type it wrong.

[LETZRIDE]

Re: Bore Spacing

i dont have access to the spare set of heads I have lieing around at the moment so I cant measure for you...but you do know you have coolant running through the heads that you need to factor in as well right?

[epsilon2322]

Re: Bore Spacing

how is that? if i'm put the itbs on top of the heads on the regular mounting points as the oem intake i shouldn't have a problem.

[LETZRIDE]

Re: Bore Spacing

how is that? if i'm put the itbs on top of the heads on the regular mounting points as the oem intake i shouldn't have a problem.

so long as you run the coolant through it...my advice to you man, and not to scare you any, is to do a TON of research on this, or make sure the shop that you have doing this does a TON of research on it...there are alot of issues that you need to work around when making one of these for the car, and if you dont think ahead to resolve these before hand, you will end up spending a ton of cash real fast... I've had to change my design about 4-5 times already, and I think I have covered all issues....there are still a few though that I will not be able to solve until the unit is on the car and ready to be fired up...

just a few things to chew on here:

- coolant routing
- tuning, how/what are you going to use?
- size of tubing and tb's....etc

the stupidest most insignifcant things have caused me to have to change things around...then you have spacing issues...amoung a bunch other that I've encountered...just saying that you should have this flawless on paper before you just dive into this.

and what kinda plans do you have for the car? ITB's will be limited to how much air can flow through your heads, etc, etc, etc...

[flamingchicken]

Re: Bore Spacing

Throttle body sizing, and venturi sizing is super important as well, to match flow and get as much power as you can.

[LETZRIDE]

Re: Bore Spacing

Throttle body sizing, and venturi sizing is super important as well, to match flow and get as much power as you can.

HUGE...along with runner length, etc, etc, etc...I've spent a couple months now designing mine...ever since my thread I created wayy back when.

I'm 99% sure I have all the kinks worked out...I'm finally ready to start stamping pieces out...I know I got all my parts pretty much...

[flamingchicken]

Re: Bore Spacing

HUGE...along with runner length, etc, etc, etc...I've spent a couple months now designing mine...ever since my thread I created wayy back when.

I'm 99% sure I have all the kinks worked out...I'm finally ready to start stamping pieces out...I know I got all my parts pretty much...

something i was wanting to do as well at one point in time. I was gonna try to make these work.

http://cbperformance.com/catalog.asp?ProductID=412

its for a vw engine, but i figured since my uncle has a complete machine shop, i cound cut and make it work.

[LETZRIDE]

Re: Bore Spacing

something i was wanting to do as well at one point in time. I was gonna try to make these work.

http://cbperformance.com/catalog.asp?ProductID=412

its for a vw engine, but i figured since my uncle has a complete machine shop, i cound cut and make it work.

u could...you still need to make something to flow them to the heads...still have to worry about your coolant issue, tunning issues etc, etc...and see what I mean about the cost shooting up real fast if you dont do your homework...tbs by themselves run you close to $1000 if not more for those....plus w.e else you need now as well...which is fine, every project has costs...but you'll watch those costs double or triple if you dont make sure you work out all your issues from the start...you'll build it to tear it down again...

I will most likely be making a kit that I will make available to those interested in it...ready and bolt directly onto the the car...from what I have here on paper and the visual in my mind...I think alot of guys are gunna love this...

epsilon buddy, Im not tryna discourage you either man...just want you to realize how much there is to making these, and really think it through when you do design and do your own...cause you can dump money into this FAST...I thought it was real easy until I began working through every possible issue I could encounter when doing these...then realized stupid small things that make the car run that you take for granted, really screw you over...