6.5 to 6.6Liter 403cu is it possible.......? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

jesse454545 · 02-04-2015, 12:13 AM

Okay so my car just went thru a major engine overhaul and my mechanic which is a very knowledgeable and reliable mechanic was complimenting on the work that was done to my engine prior to me taking it to him. One of the thing he talked about was the heads being bored out. He took some measurements and replied to me with the cylinder measurement was 4.090, he then did the measurements and came up saying that my liters where between 6.5L and 6.6L, is this possible? The previous owner did the work to the engine and I didn't know any of this till now but I have 556rwhp tested by Hennessy Performance with all bolt ons and no supercharger.

jesse454545 · 02-04-2015, 12:14 AM

I'm not at all a certified mechanic or know much about Cubic inches that's why I posted this here for I can get a certain answer that it could be possible.

blake-b · 02-04-2015, 12:32 AM

Just because the cylinder head combustion chamber diameter is (or may be) 4.090 that doesn't mean the cylinder itself it. You need the block cylinder bore to determine cubic inches. If your cylinder bore is truly 4.090, your crank's stroke would have to be in the area of 3.835 to have 403 cubic inches. That is an odd stroke LS crank if it really is that stroke.

If you know, what:
block was used?
what stroke crank?
what heads?

jesse454545 · 02-04-2015, 12:40 AM

No I do not know that information but when he first told me that my heads where bored out I told him to give me the measurements and he gave just gave me I guess the diameter which was 4.090 and I'm not sure of all the other information .

blake-b · 02-04-2015, 01:00 AM

If you can find out definitively the stroke and bore of the cylinder, its just math to figure out the rest.

AES makes engines that are 390ci and they use a Callies 3.8 stroke crank. Callies also makes a 3.875 stroke.

I guess what I'm trying to say is "Yes" it is possible:
A 4.030 bore block with a 3.875 stroke crank is 396 cubic inches (6.5L)
A 4.060 bore with a 3.875 stroke is 401 cubic inches
and there are other combinations that would get you into that ballpark.

It would drive me nuts not knowing what was in my engine. I'd be calling or otherwise contacting people to find out if my mechanic didn't know all the measurements.

SomeGeoffGuy · 02-04-2015, 08:57 AM

I had a 403 in my fourth gen but it was 4.0 stroke by 4.005 bore. That is a pretty common iron block performance recipe. It is pretty easy to tell if you have an iron block too.

-Geoff

jesse454545 · 02-04-2015, 09:32 AM

I'll ask him today if he took down those numbers as well and can I tell if I have an iron block by just looking at it or is that something you need to do while the engine was apart?

02-04-2015, 12:13 AM	#1
jesse454545 Drives: 2011 CAMARO 2SS/RS Join Date: Feb 2013 Location: SAN DIEGO & TEXAS Posts: 345	6.5 to 6.6Liter 403cu is it possible.......? Okay so my car just went thru a major engine overhaul and my mechanic which is a very knowledgeable and reliable mechanic was complimenting on the work that was done to my engine prior to me taking it to him. One of the thing he talked about was the heads being bored out. He took some measurements and replied to me with the cylinder measurement was 4.090, he then did the measurements and came up saying that my liters where between 6.5L and 6.6L, is this possible? The previous owner did the work to the engine and I didn't know any of this till now but I have 556rwhp tested by Hennessy Performance with all bolt ons and no supercharger.

02-04-2015, 12:32 AM	#3
blake-b Drives: 2009 ZR1 Join Date: May 2010 Location: KCMO Posts: 3,205	Just because the cylinder head combustion chamber diameter is (or may be) 4.090 that doesn't mean the cylinder itself it. You need the block cylinder bore to determine cubic inches. If your cylinder bore is truly 4.090, your crank's stroke would have to be in the area of 3.835 to have 403 cubic inches. That is an odd stroke LS crank if it really is that stroke. If you know, what: block was used? what stroke crank? what heads? Last edited by blake-b; 02-04-2015 at 12:54 AM.

02-04-2015, 08:57 AM	#6
SomeGeoffGuy Drives: 2023 2SS Convertible Join Date: May 2009 Location: Metro Detroit Posts: 1,062	I had a 403 in my fourth gen but it was 4.0 stroke by 4.005 bore. That is a pretty common iron block performance recipe. It is pretty easy to tell if you have an iron block too. -Geoff __________________ '12 2SS RS Convertible - Traded in. '16 2SS Convertible - White on white, mag-ride, NPP, nav. Sold! '23 2SS Convertible -Same as above except orange.

02-04-2015, 12:14 AM	#2
jesse454545 Drives: 2011 CAMARO 2SS/RS Join Date: Feb 2013 Location: SAN DIEGO & TEXAS Posts: 345	I'm not at all a certified mechanic or know much about Cubic inches that's why I posted this here for I can get a certain answer that it could be possible.

02-04-2015, 12:40 AM	#4
jesse454545 Drives: 2011 CAMARO 2SS/RS Join Date: Feb 2013 Location: SAN DIEGO & TEXAS Posts: 345	No I do not know that information but when he first told me that my heads where bored out I told him to give me the measurements and he gave just gave me I guess the diameter which was 4.090 and I'm not sure of all the other information .

02-04-2015, 01:00 AM	#5
blake-b Drives: 2009 ZR1 Join Date: May 2010 Location: KCMO Posts: 3,205	If you can find out definitively the stroke and bore of the cylinder, its just math to figure out the rest. AES makes engines that are 390ci and they use a Callies 3.8 stroke crank. Callies also makes a 3.875 stroke. I guess what I'm trying to say is "Yes" it is possible: A 4.030 bore block with a 3.875 stroke crank is 396 cubic inches (6.5L) A 4.060 bore with a 3.875 stroke is 401 cubic inches and there are other combinations that would get you into that ballpark. It would drive me nuts not knowing what was in my engine. I'd be calling or otherwise contacting people to find out if my mechanic didn't know all the measurements.

02-04-2015, 09:32 AM	#7
jesse454545 Drives: 2011 CAMARO 2SS/RS Join Date: Feb 2013 Location: SAN DIEGO & TEXAS Posts: 345	I'll ask him today if he took down those numbers as well and can I tell if I have an iron block by just looking at it or is that something you need to do while the engine was apart?