13:1 Compression 3.3L cam'n its ass off
- Thread starter zach44102
- Start date
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DJSHO91
SHO Member
Great work Zach! Sure am proud of what you've accomplished. Can't wait to see the finished product. 
The stock flow numbers were published in Superford back in the mid 90s, the article is called "Gilded Lillies" and was strictly on the SHO head. They compared extrude hone porting to hand porting (expert porter). Remeber I came away thinking either the intake, or the exhaust was worth extrude honing, while the other did better with hand porting. Vale diameters were unfortunately kept stock.
I might have a copy of this somewhere if you or zach need it..
OK so all the parts are ordered.
12.5:1 Forged Wiseco pistons
HD skirts (for nitrous)
22mm pin
KOB rods
93mm bore 3.3L
Also bought all the gaskets today, Head gaskets, oil pump gaskets, oil pan gasket, water pump gasket with o rings, oil pickup tube gasket, and oil dipstick tube.
Already got my new clevite rod bearings, cam seals, and valve stem seals.
12.5:1 Forged Wiseco pistons
HD skirts (for nitrous)
22mm pin
KOB rods
93mm bore 3.3L
Also bought all the gaskets today, Head gaskets, oil pump gaskets, oil pan gasket, water pump gasket with o rings, oil pickup tube gasket, and oil dipstick tube.
Already got my new clevite rod bearings, cam seals, and valve stem seals.
O and I need to give a shout out to Josh at SHONUT Performance for helping me get everything straight and for the awesome communication and parts offered. The best aftermarket supplier in the SHO game by FAR! Always had a great experience with them.
Awesome!!! Are you going with a 3.0 or 3.2 oil pump?
He is the man, no question!
SinisterSHO
Rust free
how many times have you changed the thread title?
Sorry I'm late to the party on this. (Just got my new computer for X-mas.)
Some thoughts to share after reading this thread...
-One of the members made a comment that well I got this and this and this and I don't make that much HP... Well combination really counts in the maximum NA HP wars...
Headers for the v6 SHO out there certainly not the same, same thing can be said about intake setups, valve jobs, cams, compression, exhaust tuning, etc.
-Out of the box 12.5 compression ratio will net a 2.8% minimum increase in engine power.
-14.1 5% minimum increase in engine power.
-http://www.motortecmagazine.net/article.asp?AID=1&AP=1
This is how I would setup the cylinder head.
-I don't know if the 75mm throttle body with net a gain, but I think its very doable. You would just need a nice taper through the main meat area before the thin plenum walls after the TB mounting ******. I calculated the intake area on a thread one time from MAF to the valve and there is a restriction in air flow volume as you approach the TB getting to the smallest volume after the TB in the Y area. Then increasing in volume after that into the two main plenum's.
As a rule of thumb even though air doesn't like to be forced in a smaller area (taper) it hates even more to be expanded into a larger area. So a small taper to match the 75mm TB should be fine, and you may even get the bonus of creating a nozzle effect in the Y area of high pressure to low pressure. Maybe some unexplained result. Be interesting to try...
-Regardless of what you do, you will only improve curve at the top in total power, but not change it's shape. The increase in compression will automatically extend the curve altogether. The valve angle and bowl blending will make improvements across the curve. The only way you will change the shape of the curve is more than likely somehow getting more air into the two plenums with another set of runners delivering more air into them. At 7200 rpm you have maxed out the capabilities of the Y section. The engine needs another breath of air to continue its march beyond 7200 rpm without dropping.
-Enlarging intake ports may help, but I think you should just make sure everything blends. In nascar world for the last 5 years intake ports have gotten smaller. There more concerned with intake velocity above all else.
-Polishing the exhaust side helps but the intake side a waste of time, 80 grit is fine.
-The head is still the biggest restriction in the engine and area of greatest improvements. Thats where you should focus the most time.
-The dual 2.5 exhaust is probably two big, and you probably lost out a little bit in velocity. Dual 2 inch would support 325-350 hp which is your target. Even more important than that is the tuning of the exhaust pipes to the correct length which should be done out on the racetrack.
-An absolute dedication to cold air source and not engine bay heat. Even a couple hundred dollars spent on the intake manifold with temp coatings can have amazing effect on engine power.
-Coat intake valves with temp coating. 2.5-3% improvement in power. Air rushing by gets super heated like the air across a heater element. Could increase the likely hood along with intake manifold coatings to run 93 pump gas with out detonation. Don't believe me? Did you know intake valves glow in dyno room with lights off?
-Maybe weld the gutted BBB to the plenum and port the hole opening to your likings. Why not? I could put a beautiful machined taper in the plenum with little work involved.
-Take a band saw and cut the two plenum opening, port, and weld back together. How else we going to get over 300HP?
I think that's all my thoughts. I really love the all out engine builds and hope to do my own someday...
Sean
Some thoughts to share after reading this thread...
-One of the members made a comment that well I got this and this and this and I don't make that much HP... Well combination really counts in the maximum NA HP wars...
Headers for the v6 SHO out there certainly not the same, same thing can be said about intake setups, valve jobs, cams, compression, exhaust tuning, etc.
-Out of the box 12.5 compression ratio will net a 2.8% minimum increase in engine power.
-14.1 5% minimum increase in engine power.
-http://www.motortecmagazine.net/article.asp?AID=1&AP=1
This is how I would setup the cylinder head.
-I don't know if the 75mm throttle body with net a gain, but I think its very doable. You would just need a nice taper through the main meat area before the thin plenum walls after the TB mounting ******. I calculated the intake area on a thread one time from MAF to the valve and there is a restriction in air flow volume as you approach the TB getting to the smallest volume after the TB in the Y area. Then increasing in volume after that into the two main plenum's.
As a rule of thumb even though air doesn't like to be forced in a smaller area (taper) it hates even more to be expanded into a larger area. So a small taper to match the 75mm TB should be fine, and you may even get the bonus of creating a nozzle effect in the Y area of high pressure to low pressure. Maybe some unexplained result. Be interesting to try...
-Regardless of what you do, you will only improve curve at the top in total power, but not change it's shape. The increase in compression will automatically extend the curve altogether. The valve angle and bowl blending will make improvements across the curve. The only way you will change the shape of the curve is more than likely somehow getting more air into the two plenums with another set of runners delivering more air into them. At 7200 rpm you have maxed out the capabilities of the Y section. The engine needs another breath of air to continue its march beyond 7200 rpm without dropping.
-Enlarging intake ports may help, but I think you should just make sure everything blends. In nascar world for the last 5 years intake ports have gotten smaller. There more concerned with intake velocity above all else.
-Polishing the exhaust side helps but the intake side a waste of time, 80 grit is fine.
-The head is still the biggest restriction in the engine and area of greatest improvements. Thats where you should focus the most time.
-The dual 2.5 exhaust is probably two big, and you probably lost out a little bit in velocity. Dual 2 inch would support 325-350 hp which is your target. Even more important than that is the tuning of the exhaust pipes to the correct length which should be done out on the racetrack.
-An absolute dedication to cold air source and not engine bay heat. Even a couple hundred dollars spent on the intake manifold with temp coatings can have amazing effect on engine power.
-Coat intake valves with temp coating. 2.5-3% improvement in power. Air rushing by gets super heated like the air across a heater element. Could increase the likely hood along with intake manifold coatings to run 93 pump gas with out detonation. Don't believe me? Did you know intake valves glow in dyno room with lights off?
-Maybe weld the gutted BBB to the plenum and port the hole opening to your likings. Why not? I could put a beautiful machined taper in the plenum with little work involved.
-Take a band saw and cut the two plenum opening, port, and weld back together. How else we going to get over 300HP?
I think that's all my thoughts. I really love the all out engine builds and hope to do my own someday...
Sean
Last edited:
SinisterSHO
Rust free
you lost me at main meat.
PITT
TURD POLISHER
This build will be epic. Good luck!
SHOlife
burnthemall
lets not have to helicoil every cam cap on these heads, walks up on zach tightening cam caps in a straight line
lets not have to helicoil every cam cap on these heads, walks up on zach tightening cam caps in a straight line
Just dont torque them down with a wrench bigger than a 1/4 drive
SHOlife
burnthemall
no same concept as here, or like headgaskets anything, start in middle, x pattern out
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