600hp mark.

[ripdog28]

My 462 with Dart heads is suppose to hit 565hp and about 560tq. The curve looks great also. I was wondering if a simple cam swap and maby a spring change maby a 600 lift with close to the same dur so i can keep it streetable. possibly a port match on the intake and heads also could get me those extra 35 hp? I would like to keep the low end tq close. Over 400Ft/lbs at 2400rpm. Oh yea, i would like to keep it a solid flat tapit. No hyd. maby a solid roller but dont want to.

I mean doesn't 600hp sound a lot better then 560?

Is port matching simple? take the larger of the two holes and grind the smaller one out right?

[Marv D]

Yeah, but doesn't 800 sound better than 600??
Be careful here. It's a slippery slope

I would suggest you get the heads flowed on a reputable bench (before you go trying any backyard port job). Then you will have some real world data to use to target a lift. If you (or a shop) does any hand port work, demand a flow test and report before AND after. I'm no bigblock guy, but I'm sure those can be screwed up just as easily as smallblock heads

[ripdog28]

Marv, I was not planning on porting at all. just a little port match for intake. I have read a ton on builds using the dart 308's and every port job i saw lost low end and only gained about 20hp up top. so a all out port job is not happening. I know 800 sounds better but i am trying to stay streetable without boost and i do think, "just a little more." I was mainly thinking a little bigger cam and hoping for 600.

[swb85]

Solid roller with enough lift to take advantage of those heads and you'll be darn close.....

[BossHogg69]

Don't expect much out of a port match. I did it on my intake/heads, but just because I wanted to. I did plenty of research on it, but I don't expect to get too much out of it. The port matching also has a lot to do with exactly how the intake sits on the motor (decked block, milled heads, etc).

check this article out: http://www.circletrack.com/techartic...ing/index.html

At this point, imo, a solid roller is the way to get that 600hp. I'm sure there's a solid flat tappet out there that may get you there, but I don't know how streetable it would be, not to mention, what is 'streetable' from one person to the next. I had to make the same choice recently, whether or not to go roller to get that 600hp, I didn't want to run a solid roller on the street, so I stuck with my XE294 (.588/.593 lift, 250*/256* duration @ .050") and will just have to be happy with the 550ish HP it will make. I didn't want the expense of having to swap over and buy springs, pushrods, lifters the whole bit - i'm already at the end of my budget for my engine!

[Super73]

I had to open up my heads just a touch when i went to the Super Vic. I did it because there was a shelf (IE intake port was slightly larger than the head port. I put the intake and gasket on and marked everything. I blended the opening into the existing port and did not go very far in to the head port at all. Maybe 1/2" and everything seems fine.

I felt that a shelf there could cause turbulance. Turbulace can be a good thing and it can be a bad thing. Not sure if I helped or hurt at there where no A/B comparo's.. But 449rwhp from a hyd roller pump gas 347 aint too bad.

[BossHogg69]

not to turn this into a thread about port/gasket matching, but here's how mine turned out. first pic is the intake, then the head.

[71Dragtruck]

Next time I'm going 900hp

[ripdog28]

[joeys66pickup]

anrt you spraying that motor or is it still N/A? if your using giggle juice.....just use more

[GMC70c20]

if you want to spend the money I would put a roller cam and a good set of roller rockers than would probably get you to the 600hp mark. without loosing any streetablility

[custom72c20]

Sweet truck!!! I bet that sucker flat out hauls. On the cam issue, I don't going with more lift will benefit you because you are already hanging the valves open a lot. If anything, I would bring the duration down, so the motor can make more compression thus more power. I think you would also benefit from a roller because it will take the abuse I'm sure your going to give it. Just get used to adjusting the valve lash if you run a solid cam. Hope this helps.

-Nick

[ripdog28]

Originally Posted by custom72c20

Sweet truck!!! I bet that sucker flat out hauls. I think you would also benefit from a roller because it will take the abuse I'm sure your going to give it. Just get used to adjusting the valve lash if you run a solid cam. Hope this helps.

-Nick

I am about to start it for the first time in the next week or two. I did not build it to just roll around, haha I built it to take an @$$ beating and keep hauling @$$..... It already has roller rockers 1.75 chrome molly Comps. The duration is a trade off for a lot of lift huh?

[ProStreet71]

You say it is "SUPPOSE" to hit 565 HP, has it been dynoed? If not, where did you get that number? You may be much closer than you think. It does not take a whole lot for a big block to make 600 HP. A custom grind cam can really make alot of gains over a shelf grind. Contact Chris Struab or UDHarold over at the Team Chevelle forum. Mike Jones over at the Speedtalk forum. These guys can grind you a cam for your specific needs for just a few dollars more than say Comp or other big companies shelf cams.

[ripdog28]

The engine spec was run thru a very accurate program, this program is within a few HP (10-20) Super73 has it. check out the link i have attached to the HP claim in my signiture. you will see how close it is compared to a few 600+hp real dyno's.

[ProStreet71]

Just noticed your cam specs and your cam seems a little small for a big block. You have quite a bit of cubes to feed there. I think I would be looking at something with duration in the 240 to 250's @ .050 and above .600's lift. My small block has a solid roller with 254in and 260ex @.050 duration and lift is .646in and .588ex with a 1.65 intake rocker and 1.5 ex and is pretty streetable. Drive anywhere I want to go. I dont use the advertised durations you have posted in your sig as they are pretty useless. Only way to try to compare apples to apples is by the @.050 numbers. Also with the nitrous I would prob be looking at something with a 112 lsa. Just going to a solid roller while net you 20 hp all by itself and another 20 or better by stepping up the cam size. With a big block I would not worry bout losing a little TQ down low, #1 there is no way you can use that much TQ on the street, #2 you will have gained it back by the time your stall kickes in, and #3 NOS will give you a HUGE boost in torque while at the track. Just my .02

[Jim_PA]

My solid cam makes less noise than my 270H did. Lots more power too. I have good poly locks on pro magnum rocker arms, and I plan on checking the lash yearly (or if I hear any ticking).

It's nowhere near .600 lift, however...