if your building an all out nitrous LSX block, 6 bolt 245cc heads, do you want to go the largest cubic inch possible? such as the 454 lsx's or 440ci? 427?

basically I understand how Turbo engines work with the lower ci and why they do it, what about nitrous engines?

what would be the benefit to a 440 compared to a 454 or 427?

Chad

 

Depends on how aggressive the rest of your motor will be, intake compression cam size will factor in if you will have enough head to support the larger cube motor.

 

vic jr. ported to the heads, accufab 4150 on top. direct port stage 1 stage 2 spraybar setup. spraying a max of 350-400. car would see limited street use, on the juice race gas in both stand alone and main tank.

245 TEA trickflow's setup for solid roller, wouldn't want to spin it any higher than 8k, stock oiling system, w/ an accusump

pump gas 12:1 CR, not sure about dynamic or cam specs...lift in the low 700's

Chad

 

Im on a 4.185 bore and im not crazy about the bigger stroke cranks.The heads will tend to be happer with less stroke and bigger bore.We are on a 3.90 stroke and we feel my heads would be happer with even less stroke.Also my heads have 310cc intake runners and flow well over 400cfm.

 

What are those, the allpro's?

I'm running the same stroke, 3.9, just with a much smaller bore, haha, i'm actually still using the original block that came in my car, she's done me well!

 

*whistles* not looking to go as extreme as you are, looking for 8.50's on the juice. so you would suggest a de stroked motor then?

what about a 417? 4.125 bore/3.90 stroke 245cc heads to much for that combo? I would think the 235's would be a better fit?

Chad

 

Canted valve ET heads.

 

Wow, didn't know they made 'em with runners that big and I have a friend that bought the allpro's and he said the runners were retarded big on them, so I thought it might be them, that's awesome, ET heads are the ****! Buddies got a set of the 265's on his 408 with twins, they are really nice heads!

 

I don't think the 245cc heads would be to much.I think that would be a nice bore stroke combo and should put you were you wanna be.

 

appreciate the feedback

Chad

 

Sorry to bug you with questions, but with my bore and stroke (3.907 bore x 3.900 stroke) what do you think would be the largest head to go with for max effort on the nitrous, runnin a futral cam motion grind 246/257 .632/.645 112+4 hydraulic roller shifting around 7500 and it's got a GMPP carb intake on it port matched to the heads with an accufab 4150 tb on top. Right now I have a set of 5.3 heads on the car worked by TEA, flow 317@600 lift and have 2.055 intake valves with 1.57 exhaust valves, 225cc runners. I was thinkin about little things I could do to get a little more out of her with this setup since i'm gonna be running it for a while. Will be hitting it with 300 - 400 from a plate setup, probably a speedtech, maybe a wilson (have a buddy that gets killer prices on the wilson stuff and i've heard it's a pretty good plate). I'd like to get 8's out of this little motor if possible, and go as deep into the 8's with it as possible without really pushing it totally to the edge. Do you think I would see much of a gain with a different set of heads? I was thinkin a set of ETP's, but didn't know which ones to go with. Right now i'm on a borrowed cheater plate with a little 250 shot and i'll have some times on it saturday (our local 1/4 mile is finally opening back up after being down for renovations for 6 months), gotta get the a/f dialed in, it was running off the chart rich (under 9.0 on my wideband and plugs confirmed it) when I went to the local 1/8th and like that it went 6.12 @ 114 on the first pass out after I got my grounding issue fixed on my controller and I haven't played with it since, but I think I should see at least a couple mph gain when I get the air fuel right and with the better track I should be back into my normal low 1.3 60's instead of the 1.40 I got at the junky 1/8th mile, so maybe a 5.8 - 5.9 in the 1/8th and hopefully a 9.2 - 9.3 in the 1/4 just on the 250.

 

Tuff, what 3.90 crank are you running?

same with you Devon.

Chad

 

Mine's an Eagle, got the rotating assembly kit from Jegs when I originally put this motor together, Eagle crank, Eagle Hbeams, and JE pistons, got arp everything and clevite bearings.