Free torque at the expense of top end???

[chevy_big_block_bro]

everything is going to cost you something.
Gaskets, cleaning heads up etc

If you have access to a welder and mill, why don't you have a crack at upping the ratio of the rockers by moving the pushrod seat closer to the pivot point. You would have to get the measurements right and make a jig so they're all the same but its worth a shot if your good on the mill.

 

[klampy]

it doesnt have the bellmouth, its an ecotec. but i do want to look at a spacer kit. and i hadnt actually thought about a custom tune, i had put it into the "DYNO = $$$$" pile.... ill have a look on ebay later, right now tho, iv found a thread on cam specs for the ecotec:

(QUOTE)
Standard Valve Timing for the LateVS-VT-VX-VY EcoTech V6 Engine:

Advertised Valve Lift at height - 0.006 inches
Inlet Opens - 6.7 degrees BTDC
Inlet Closes - 57.0 degrees ABDC
Exhaust Opens - 65.3 degrees BBDC
Exhaust Closes - 15.1 degrees ATDC
Inlet Valve Duration - 243.7 degrees
Exhaust Valve Duration - 260.4 degrees
Inlet Valve Lift with 1.6 to 1 ratio rockers - 0.4099 inches
Exhaust Valve Lift with 1.6 to 1 ratio rockers - 0.4112 inches
Inlet Valve Lift at TDC - 0.0208 inches


so if im reading it correctly, (if advanced 8 degrees) would make my
Inlet open @ 15.7 BTDC
meaning the valve opens earlier on the upstroke of the intake cycle. allowing the piston to push more air back into the IM?? could i possibly use that to my advantage by somewhat pressurising the plenum and helping the scavenging affect???? particularly with longer runners???

Inlet close @ 48 ABDC
meaning the valve closes earlier, preventing some of the Air/Fuel mix from blowing back into the plenum ( i see that particular as a positive)

EX open @ 74.3 BBDC
meaning the exhaust valve opens just over halfway down allowing a lot of exhaust energy out (maybe a negative, or could be positive in helping draw more air back in on the overlap)

EX close @ 6.1 ATDC
meaning that just past the top of the stroke the EX valve shuts preventing any more EX gas being sucked back into the chamber allowing any scavenging to build up speed as the piston moves back down (hemholtz??)

after re-reading my story i can start to visualise whats happening internally and i really believe that this will give me more torque in the lower rev range. and i dont care about the lost power in the top end.

 

[klampy]

everything is going to cost you something.
Gaskets, cleaning heads up etc

If you have access to a welder and mill, why don't you have a crack at upping the ratio of the rockers by moving the pushrod seat closer to the pivot point. You would have to get the measurements right and make a jig so they're all the same but its worth a shot if your good on the mill.

yea, about the mill part, its not mine. so im only adept at cutting flanges n stuff like that. so maybe not my go on that one....

and i have a budget of $400 for everything. including rebuild parts. so not alot. im just sooooo lucky i get alot of stuff at mates rates, and i can get genuine holden parts at cost thanks to my dad who works in parts.
its almost a pity i dont own a nissan coz i work in spares for Nissan.... lol

 

[delcowizzid]

i wouldnt mess with cam timing i just ran the stock ecotec cam up in the sim software looses lots of torque from 1500rpm upwards at 8 degrees advance

 

[chevy_big_block_bro]

ah ok

You also mentioned MDF as an insulator/spacer.
I'd say no to that because it will get impregnated in oil from the PCV and swell.

I have a 12mm one here. Make an offer, I don't need it no more.
You'll just need to cut 4 little 12mm long aluminium spacers with a 6-7mm hole to go between the plenum and fuel rail coz I lost them years ago lol
Its in perfect condition with the longer bolts to go with it

Edit

I have 4 of the 5 bolts but it wont take long to turn down one more

 

[klampy]

i wouldnt mess with cam timing i just ran the stock ecotec cam up in the sim software looses lots of torque from 1500rpm upwards at 8 degrees advance

if altering the cam timing is gonna kill the torque is that with no other changes at all?

 

[delcowizzid]

i changed a few things to test it out youre better off getting wade to regrind a high torque towing grind onto the cam for $280 than to advance it

 

[klampy]

what about retarding the cam the same amount?? what effect does that have?

 

[klampy]

for what its worth, is getting the crank offset ground worth it?? would i need shorter rods to stop the piston hitting the head??

 

[delcowizzid]

grinding the crank is not really worth it would cost a lot to get done and weaken it a lot due to how they are made and pistons would stick out the block a lot LOL they allready stick above the block on ecotec.advancing the cam just moves the power up higher in the revs and broadens the torque curve a tad.if it was me ide just slap a totally stock second hand engine in and be done with it.by the time you add up gaskets bearings rings for a quick freshen up its allready getting up in the price .if you go further than just the basics costs will climb due to machining and new pistons getting rods resized etc.if its knocking bad from a dead bigend the crank will pretty much be rubbish now anyway or at least need a good seeing too the journals wont be round any more