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Ok so this is not going to be a turbo build, I have boost to play with in my other but I thought I'd post here as you guys have plenty of experience in 3L 8v.
I have a bunch of parts in the corner of my garage (see below) and I have decided I want to build a street use big bore 8v na. I have:
An 87 turbo block with scored cylinders
A good 3L crank
A good na 8v head with stock valves & cambox
Forged 951 rods
Complete new TecGT with all the fittings and harness
Sequential and DFU's
A good 86 951 LSD roller with everything minus the engine.
I don't want to hear about turbos or 16v, tell me about sleeving, bigger intake valves, pistons, comp ratio (on premium), etc. I'd like to make use of as many of the parts I already have. What would you do to build a badass big bore 8v na with this pile of parts?
I would build a Hybrid Stroker 3.2L. 95 mm stroke, 104 mm bore, 12:1 CR, fanged iron sleeves. The head, 48 mm valves, ported. Should be a torque machine
I would build a Hybrid Stroker 3.2L. 95 mm stroke, 104 mm bore, 12:1 CR, fanged iron sleeves. The head, 48 mm valves, ported. Should be a torque machine
Shawn I've read your build thread and scoured your website many times and a hybrid is definitely one of my choices. However I'd really like to keep the crank and rods stock if I can. Are there any 2.5 sleeves out there that would accommodate a 106 bore?
Another question is 12:1 CR the best you could achieve with your non-interference pistons? Can I go higher CR and still maintain premium gas and non-interference?
Shawn I've read your build thread and scoured your website many times and a hybrid is definitely one of my choices. However I'd really like to keep the crank and rods stock if I can. Are there any 2.5 sleeves out there that would accommodate a 106 bore?
Another question is 12:1 CR the best you could achieve with your non-interference pistons? Can I go higher CR and still maintain premium gas and non-interference?
Sounds like a cool project.
106 bore is going to require a much more expensive sleeving. 104 is pretty easy and cheap to do. Mitsu Eagle Rods are less than $400. The extra stroke changes everything. I would NEVER build a motor with the stock rod bearings with the options we have now. Just my opinion. If you have custom JE piston made (which are not a lot more) you can make CR pretty much what you want.
106 bore is going to require a much more expensive sleeving. 104 is pretty easy and cheap to do. Mitsu Eagle Rods are less than $400. The extra stroke changes everything. I would NEVER build a motor with the stock rod bearings with the options we have now. Just my opinion. If you have custom JE piston made (which are not a lot more) you can make CR pretty much what you want.
Your wisdom might prevail here, I'm just hesitant at reworking a perfectly good 3L crank. However the advantages of superior rod bearings are sort of swaying me at this time.
106 bore is going to require a much more expensive sleeving. 104 is pretty easy and cheap to do. Mitsu Eagle Rods are less than $400. The extra stroke changes everything. I would NEVER build a motor with the stock rod bearings with the options we have now. Just my opinion. If you have custom JE piston made (which are not a lot more) you can make CR pretty much what you want.
Do you have a picture of the crank with the mitsu rods? Just wondering how it works out with clearance?
Your wisdom might prevail here, I'm just hesitant at reworking a perfectly good 3L crank. However the advantages of superior rod bearings are sort of swaying me at this time.
Cash in the 3.0 crank and you'll probably get an offset ground 2.5 crank and the mitsi rods with the proceeds.
Shawn Mitsu rods you posted from the site you used are on sale for 326.00$
To the poster you could buy a set of SB pistons and sell 4 to another RL member. Just a thought
Originally Posted by refresh951
Sounds like a cool project.
106 bore is going to require a much more expensive sleeving. 104 is pretty easy and cheap to do. Mitsu Eagle Rods are less than $400. The extra stroke changes everything. I would NEVER build a motor with the stock rod bearings with the options we have now. Just my opinion. If you have custom JE piston made (which are not a lot more) you can make CR pretty much what you want.
Your wisdom might prevail here, I'm just hesitant at reworking a perfectly good 3L crank. However the advantages of superior rod bearings are sort of swaying me at this time.
Imo the smaller bearings are a superior design. I tgink Dukes, Shawns, my builds have proven tgem out by now.
Persobally, I'd do a 3.3 using a stoked 3.0 crank, and a sleeved 2.5 block.
Originally Posted by KSira
Do you have a picture of the crank with the mitsu rods? Just wondering how it works out with clearance?
It's all in the DIY hybrid thread. There is plenty of clearance.
I also prefer using ACL race bearings for the rods not only for the durability, but they offer different sizes to adjust the oil clearance in 1/2 thou increments. If only someone made a better set of bearings for the crank mains. It would be really nice to have a set of .025 size bearings for adjusting main oil clearance.
I also prefer using ACL race bearings for the rods not only for the durability, but they offer different sizes to adjust the oil clearance in 1/2 thou increments. If only someone made a better set of bearings for the crank mains. It would be really nice to have a set of .025 size bearings for adjusting main oil clearance.
I see no issue with the standard Glyco main bearings. There's no need to get fancy here. They don't fail. Rods, of course, are a different story.
...Personally, I'd do a 3.3 using a stoked 3.0 crank, and a sleeved 2.5 block...
Who produces sleeves to accommodate a stroked 3.3 build on a 2.5 block? I have searched but only found sleeves for a 3.0 S2/68 block that could be bored that far.
Darton mid sleeves with 106 mm bore can be used in a 2.5 l block. Can be bored to 108 I believe.
If you go the 3 liter crank route in a 2.5 block you will need new rods because of clearance issues (looks like you got that covered but you may want to double check the clearance).
You will also need a custom head gasket as the standard ones only go out to 104 mm for a 2.5 block, Cometic will work with you.
Milledge makes a cam kit for the 8v head that will give you a longer duration and better springs.
With the steel Darton sleeves your piston choice is wide open.
You may want to look at a custom intake with velocity stacks to improve airflow.
Knife edge the crank, aluminum fly wheel, KEP clutch.
With a NA 8v head, you can look at porting and polishing
10-23-2014, 10:34 PM
Help me build a 3L+
