
8000+ RPM holden 6
#1
_why-psi_
Posted 26 February 2007 - 09:40 PM
something like H beam chev rods i was thinking, any ideas of toughening up the bottom end? im going to add a main cap girdle to help.
#2
_82911_
Posted 26 February 2007 - 09:47 PM
Cheers Greg..
#3
Posted 28 February 2007 - 06:57 PM
#4
_uglybob_
Posted 28 February 2007 - 07:48 PM

#5
Posted 28 February 2007 - 07:58 PM
#6
_70rey_
Posted 28 February 2007 - 08:02 PM
#7
_why-psi_
Posted 28 February 2007 - 10:22 PM
#8
_runna_202_
Posted 28 February 2007 - 10:56 PM
runna 202
#9
_why-psi_
Posted 28 February 2007 - 11:03 PM
#10
_82911_
Posted 28 February 2007 - 11:41 PM
long gone now.
308 adv dur probably around 250@50 take off a bit because it will most likely be a hydraulic as most of the heatseekers were hydraulic if i remember correctly.
lift in the area of .500" I'd say it would be all over red rover by around 7000rpm tops.
On the subject of 8000rpms.. you don't need that sort of engine speed.. SERIOUSLY....
The heads don't flow the air to need those sorts of engine speeds.. well unless you are trying to make 300hp on a 149 red bottom end.Then it is possible that you would need to turn it that hard to use the avaliable airflow.
There is a direct relationship between airflow potential of the head and RPM versus engine displacement...
My opinion is that you shouldn't listen to all you have heard from mates, and mates of mates

Cheers Greg..
#11
_runna_202_
Posted 01 March 2007 - 12:24 AM
i was recommended it by and engine builder due to the charteristics of the cast iron heads. it makes as its power at about 6800-7000, he recons the cylinder heads fall over after that kind of rpm.
#12
Posted 01 March 2007 - 10:29 AM
because they can, but it kills them. Can tell you all about it. I'm 99% sure the cam in my 300hp 202 has a duration of 340can i ask why u wanna rev her about 8 grand mate???
Edited by lakeside, 01 March 2007 - 10:30 AM.
#13
_Drag lc_
Posted 01 March 2007 - 05:25 PM
may i ask what sort of head you are using, is the current head on a red or blue/black bottom end?
thanks Hayden
#14
_Drag lc_
Posted 01 March 2007 - 05:47 PM
Thanks Hayden
#15
_82911_
Posted 01 March 2007 - 06:04 PM

answer is 360 buddy....

If you had 340 degrees of seat to seat duration on the cam that only leaves 20 degrees of rotation in which to fire the thing and generate downward pressure on the piston crown.
Take from the 20 degrees the 7 or so degrees that the piston dwells at the top of the stroke and you are now down to 13 degrees....
Ignition lead time for a petrol engine is typically 30degrees BTDC to account for the burn rate of gasoline fuel.
Fairly sure most of your still burning charge is going to be coming out the exhaust mate....
Still i could be wrong...

Sorry for the dictatorial lesson in the limits of the otto 4 cycle engine, just all this mine is bigger than yours shit gets a bit much after a while

IT IS ALL ABOUT THE COMBO PEOPLE NOT THE SIZE OF THE COMPONENTS...
can we process the facts please...
Cheers Greg..
#16
_why-psi_
Posted 01 March 2007 - 06:21 PM

the head on it now is a ported red (can reach in and grab the valves) and its on a red bottom end with black crank.
the new motor will have a 12 port head on a blue bottom end
#17
Posted 01 March 2007 - 07:23 PM
I sent my lc gtr in to have a 1/4 painted before selling(and he f*ck it ), drove home and put in shed. Started the gtr the next day and it broke. I were playing with the carbs and reved it and a funny noise started. I found the cam retainer broken with the 2 screws still tight in the block.
#18
Posted 01 March 2007 - 07:30 PM
#19
_Drag lc_
Posted 01 March 2007 - 08:01 PM
i totaly agree here


why-psi, did you find out whitch bottom end to use.
Thanks Hayden
Edited by Drag lc, 01 March 2007 - 08:07 PM.
#20
_why-psi_
Posted 01 March 2007 - 09:40 PM
#21
_82911_
Posted 01 March 2007 - 09:52 PM
Colin.... 322 degrees sounds better....still a 7/11 grind though (open all hours)

Cheers Greg..
#22
_rorym_
Posted 01 March 2007 - 10:01 PM
Psst!..Listen closely..He knowd what he be talking about Bwanna!Hey Lakeside.. how many degrees in a full revolution mate?
![]()
answer is 360 buddy....![]()
If you had 340 degrees of seat to seat duration on the cam that only leaves 20 degrees of rotation in which to fire the thing and generate downward pressure on the piston crown.
Take from the 20 degrees the 7 or so degrees that the piston dwells at the top of the stroke and you are now down to 13 degrees....
Ignition lead time for a petrol engine is typically 30degrees BTDC to account for the burn rate of gasoline fuel.
Fairly sure most of your still burning charge is going to be coming out the exhaust mate....
Still i could be wrong...![]()
Sorry for the dictatorial lesson in the limits of the otto 4 cycle engine, just all this mine is bigger than yours shit gets a bit much after a while![]()
IT IS ALL ABOUT THE COMBO PEOPLE NOT THE SIZE OF THE COMPONENTS...
can we process the facts please...
Cheers Greg..
R
#23
_why-psi_
Posted 01 March 2007 - 10:16 PM
#24
_mikek73xu1_
Posted 02 March 2007 - 07:30 AM
This is a hyd cam and rocker ratio is 1.5:1
In. Ex.
Camlift: .322" .327"
Valve lift 1.5:1 ratio .487" .490"
Duration at .050" camlift 230 deg 236 deg
Lobe centreline- [ maxlift ] 105 deg atdc 111 btdc
Lobe separation 108 deg
This info is off my cam card and description given is : power range 2900 - 6400 rpm, strong mid range with good top end.
And to drive thats exactly how it is. I could go for a bigger cam and pull more revs but this is a really reliable combo that has enough grunt to have some fun. Plus my budget doesnt allow for engine rebuilds every 5 minutes !
Edited by mikek73xu1, 02 March 2007 - 07:39 AM.
#25
_nibbsy_
Posted 04 March 2007 - 01:41 AM
the latest street machine has an article on how to make a 300hp 202 and its pretty full on. Just hope you have a fair wad of cash or know someone who knows someone.
Although a 300hp 202 in an lj would be awesome fun!!!
Horsepower is horsepower no matter where it comes from!!!!!!!!
nibbsy
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