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I bought a set of dart iron eagles awhile back with 215cc runners, 58 cc chamber I believe, screw in studs and guideplates. I bought these heads because I figured they'll flow just about anything I want to do and the price was right. For motors right now all I have is a 355 (cam yet to be determined), how much cam would I need to run to really get the potential out of these heads, or is it even possible or logical on such a small displacement? From what I understand these heads will easily support 500-600 hp range, is it possible to achieve with 355? my ultimate goal would be to get around 400 rwhp (chassis will of course be built to support it), thanks in advance guys
What tranny and rear end are in the car, and are you willing to change those?
To have these work best, you want to cam it up pretty hard. This will suck as a street car, are you ok with that?
Are you willing to use a solid roller cam? (price of it being the concern?)
What's in the shortblock? Pistons? Balanced?
but with any good sized cam most factory issued springs/valvetrain parts arent strong enough or have the proper specs. I have to upgrade springs on my AFR's
If you get good springs, a big hydraulic roller with the proper lobes can be controlled past 6700rpms or so where you''ll want to spin it with those heads. A custom grind similar to the GM847 cam wouldnt be a bad place to start. they will make power to 6800. it will be lazy on the low end, and lope like crazy, but my gosh will it pull hard over 4000 rpms!! should make over 400whp.
What tranny and rear end are in the car, and are you willing to change those?
To have these work best, you want to cam it up pretty hard. This will suck as a street car, are you ok with that?
Are you willing to use a solid roller cam? (price of it being the concern?)
What's in the shortblock? Pistons? Balanced?
I just installed a new 700r4 that should be good to about 550hp but when other motor goes in it will likely be followed by a built th400 with 2800 stall I have lying around as well as a swap to a disc rear end with moser axles and true trac. How bad will this suck on the street? Solid roller price is not an issue but I still want to street the car a bit, would I be better off just increasing the displacement (i.e. stroke to 363, 383, or 397)? If that would just make more sense it's not out of the question, I have a friend nearby with a reputable speed shop, he built it to where it is now. also, yes balanced and forged pistons
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where would I be able to find spec for a GM847 cam?
Last edited by imaking; 01-23-2008 at 04:30 PM.
Reason: Automerged Doublepost
A stroker motor would increase your compression like crazy, you'd want dished pistons. Not a bad plan, but now you're replacing your entire rotating assembly around a set of heads. Sure that's what you want to do?
Spend $2000 on shortblock to force an existing setup to match $800 heads? (or whatever you paid for the heads, since you say you got a deal)... If you think you can sell or reuse your existing rotating stuff later on, then great.
Do you intend on mixing your own race fuel? Or are you willing to run E-85? You'll want a high CR. ~10.5:1CR is entry level IMHO. Just right on the ragged edge. I'd look at a 245/245@.050" type of range in a solid roller. A solid roller will give the widest powerband. Check the flow chart on those heads, if they are over .7 E/I flow then stick with a single pattern.
Probably on around a 108-110LSA would be my guesstimate. You'll have a high powerband that's for sure.
The valve train parts are going to be fairly high end and pricey though. It should make your 500fwhp or so though.
A stroker motor would increase your compression like crazy, you'd want dished pistons. Not a bad plan, but now you're replacing your entire rotating assembly around a set of heads. Sure that's what you want to do?
Spend $2000 on shortblock to force an existing setup to match $800 heads? (or whatever you paid for the heads, since you say you got a deal)... If you think you can sell or reuse your existing rotating stuff later on, then great.
Do you intend on mixing your own race fuel? Or are you willing to run E-85? You'll want a high CR. ~10.5:1CR is entry level IMHO. Just right on the ragged edge. I'd look at a 245/245@.050" type of range in a solid roller. A solid roller will give the widest powerband. Check the flow chart on those heads, if they are over .7 E/I flow then stick with a single pattern.
Probably on around a 108-110LSA would be my guesstimate. You'll have a high powerband that's for sure.
The valve train parts are going to be fairly high end and pricey though. It should make your 500fwhp or so though.
stroking this motor has crossed my mind a few times especially because it's just sitting there, begging for mods, and I am currently running a 355 in my camaro. I do not intend to mix my own fuel but a gas station 5 min. from my house sells 100 octane, I had a truck I ran 100 through on a regular basis as a daily driver (ish). Thanks for the info on the cam, not HAVING to spend a bunch more money on rotating assembly and getting my desired HP would be schweet
well first find out what pistons you have in that 355 of yours. 58cc chambers will push 11 to 1 with flattops. That aint bad tho. with large runners you'll want some compression to help build lowend power to lug that car around. you can also use a tad less cam to make similar power as lower compression cars with bigger cams. I think it will be a good combo
but it all depends on the pistons and how far down in the hole they are. you will want to keep quench distance to around .040 with that compression to help control detonation. Run 93 octane with somewhat conservative timing and i think it will be fine. So if your zero decked then standard .039-.040 gasket will work great. else, if your in the hole, find a gasket that will work to give you the proper quench.
Stroker would push race gas only compression limits if you have flat tops.
that compression and a fairly large 236/242 hydraulic roller or a solid roller in the 240's will make 400whp for sure, or close to it
then you gotta think about the induction, i'm assuming thsi will be carbed? what intake you plan on using? solid roller or a big hydraulic will want a single plane i'd say, like a victor junior 3000-7000 rpm range.
I also have a set of Vortec heads, for streetability purposes would I be better off just having these worked and put them along with a XE274, XE284 or ZZ-X cam and rpm air gap/victor jr. on the 355? It seems this is quite a popular setup on these forums, appx. how much power would this setup yield?