RED_DRAGON_85

is there any reason why someone starting from scratch shouldn't use a cam-head combo such as this:
http://summitracing.com/parts/TFS-K3...0/?image=large

basically my block is on its last legs and i am beginning to do research looking for parts to put in a newer roller block.

just for the simple fact that you can get everything in one place, these combo deals seem to be a good deal.
is there anything i am missing?

this kit comes with a 230* cam with .528" lift on the intake and 234* and .539" exhaust.
i dont know a lot, but this is a pretty decent cam and should be pretty well suited to the heads that it comes with.

the 72cc heads with a 350 crank will need dome pistons to have a decent compression ratio, but thats not a big deal IMO
(by decent i mean on the ragged edge with premium gas and an engine that wont go above 200* even on a hot day)

just for curiosity's sake, is there anything that you would change in this situation?
i am basically looking to build a roller engine in the 450 hp (crank) range for strictly street duty.
i really enjoy driving fast and accelerating from stoplights, so it needs to be responsive (meaning good low rpm manners, or at least semi-good manners... as long as its not a dog below 2k then im happy)
ideally i would keep the TPI, but i am beginning to realize that this simply cannot happen given the power i want.

Rolling Thunder

Well unfortunetly theres a bit of deception going on here. Curious about how they can rate motors without specifying the conditions under which they were tested? Well it just so happens that 465 hp 5.7 L kit wasnt tested on a 5.7 at all. The 465 hp was derived from that kit being installed on a 383. Sneaky isnt it? Now on to your real question is there any point to buying all that stuff piece by piece or in a kit? For the most part the kits are a nice way to just buy it and forget it no guess work. However they are kinda like a one size fits all glove they just fit everyone equally poorly. Thell work just fine for the most part but there not taylored to your specific needs. Now for the most part like a one size fits all glove who cares? For someone with very specific requirements a kit just wont "fit" very well. That being said lets talk about your goal for a min. I think your goal of a 450 hp crank from a strictly street driven motor that needs to have good low end torque might be pushing it. Its kinda a conflict of goals. You want to build alot of high end HP when youll 99% of the time be running in the low RPMs on the street. Keep in mind HP is kind of an abstract thing you cant feel horsepower as its a measure of power where as torque is a measure of force. HP is a combination of how much torque exsists at a particular RPM. Now in a high HP motor all youve really done is shifted your torque curve up into the higer RPM. Now without getting into a long discussion as the differences of torque and HP and why people talk about HP and not torque why we even care about HP bla bla bla ill just summarize by saying this. Torque is what you feel as again it is an actuall measure of force. From the physicas equation Acceleration = (Force/Mass) you can easily see the car that generates the most force will have the highest acceleration which is really a no brainer right. so if you build a high HP car that means youve shifted your torque curve higher in the rev range which means in the lower RPMs where your typically are on the street you will have less torque available to you. This means the car will not accelerate as fast feel as powerful ect untill it gets into the higher RPMs. This dosnt really make sence. If your going to be in the low RPMs you should try to build performance in the low end/mid range where you typically are on the street. This will give maximum effect on the street. The other option is to swap to a larger motor then this could be accomplished realitivly easily.

RED_DRAGON_85

i am aware of the definition of HP and Torque and how they affect each other.
you bring up a good point though.
i had been under the impression that building torque was the name of the game and HP came as an added bonus.
however after reading so many threads on "my 383 makes 700/600/500 hp" and such, i guess my eyes got bigger than my proverbial stomach...

that being said:
a) i WILL be building a roller cam engine. nothing short of a flat tappet block falling on my doorstep can dissuade me from this.
b) said engine will spend 90% of its time below 4500 rpms and more than 60% below 3000
c) i want more of a grin than i get now with my current 350.


my current setup is a 350 block from a 70-82 dumptruck with completely unknown internals.
the PO did the swap and provided me with absolutely no idea as to what is in it.
without pulling the thing apart, i can tell you that it has roller tip rockers, possibly even full roller rockers, but i cannot tell without pulling the valve covers, something i am disinclined to do without reason. mere curiosity is not enough.
i have a 305 TPI with ported or "large bore" runners.
the chip i am running is "custom"


a 383 is going to cost basically the exact same to build, the only difference being the crank and rods.
that being said, i would love to build a huge engine using a 4" stroke crank, the only problem is that the compression ratio would be way too high even using 74cc aluminum heads and dish pistons (there arent many that will work with that large a stroke)

i get what you are saying about the one size fits all glove, but
what doesnt make sense to me is this:
aside from the heads and cam, the only thing left that seriously affects power output are the intake and crank.
assuming a 383 crank, you are left with the intake.
most people will be running a air gap or similar manifold and a holly carb, so basically, what they advertize is IMO doggone close to accurate.
correct me if i am wrong here.

Rolling Thunder

Well its true i wouldnt argue that thoes advertised number are incorrect. If you used the parts they did at the compression they did tested it under the circumstances they did and so on and so forth everything should be the basically identical. However keep in mind for example our exhaust systems arnt the greatest and when they tested their motor they probably had nice large long tubes bolted on and not much else so youll see a bit of a difference there. Also accessories like AC and power steering load down the motor and they most likely didnt have any bolted on so again that will drop thoes numbers a bit too. All these little things add up. So again thoes numbers i would expect to be a decent representation as to what youde end up with but in real life they will be some differences, explainable differences, but not as good as advertised. The main reason i brought it up though was because that 465 hp advertisement was based on a 383 which they did not make clear on that page they even said for the 5.7L which leads you to believe it was tested on a 5.7L. Since you were talking about useing a 350 then their would be quite a difference obviously not only in peek number but in the general shape of the torque curve itself.

camaro71633

Anyone else notice that the pic for that kit is parts for a small block ford not chevy. I was looking at the intake and valvecovers and was like wait a sec somthing isnt right here haha.

RED_DRAGON_85

yeah, lol, and the pic includes a manifold, which the actual kit does not