|04-23-2009 07:23 PM|
It does matter in very finely tuned engines. It really affects cylinder filling and rotating weight among other things, but sometimes a shorter rod may be better. In all reality though it does not make enough difference on the street to worry about.
|04-23-2009 07:21 PM|
I wasn't trying to imply the 270H is a bad choice, its a good one for this type of street combo- though there are other equally as good ones for a little cheaper if you look hard enough.
And the head recomendation was assuming he not only ported the heads himself, but also redid the seals, installed the valves and springs, and cleaned them- basically everything but cut the new valve seats (I realize most people are not set up for that). It was a strict budget build. If you're going to drop $1500 on heads (as opposed to my $350 version which beats even VOrtecs by a long shot as far as power/dollar) then those are by far better choices than porting stock castings. I was shooting for low end hyper pistons (thoguh check for right comp ht), a possibley used intake (RPM's are everywhere), a budget cam, a used rebuilt carb, and cheap painted headers.
Hell if the block was in nice enough shape he could even hone it himself.
Otherwise I'd go a whole different route.
|04-23-2009 06:36 PM|
|roknroy||on the rod ratio, i called joe sherman many years ago, and one of the things he said were " rod ratio doesn't matter, i've made 600 hp with those chickensh@t 400 (5.65) rods". it sounds good on paper, but doesn't show up on the dyno.|
|04-23-2009 05:29 PM|
|my87Z||wouldn't a 750 cfm carb be a bit overkill for a 327 with a cam not meant to go over 5500 rpm, i would think you would stick closer to 600 cfm maybe 650|
|04-23-2009 05:27 PM|
|my87Z||depends on whether you want to spend the extra 500 on a set of alm heads or not, i know that dart makes steel heads but ive never heard of afr making steel heads|
|04-23-2009 05:16 PM|
270H has 224/224 at 0.050"
260H has 212/212 at 0.050"
Dart or AFR heads will easily out power stock gm heads of that time period. Porting stock heads makes no sense unless you do it yourself. And I don't think the guy in a head porter. Just buy good heads and move on.
|04-23-2009 04:08 PM|
Another thought if you just want a good daily driver is to do a basically stock short block rebuild, use steel shim head gaskets, ported 416 heads with a larger intake valve (small chamber with good flow), an RPM intake, headers, and a cam around 220/225 duration @ .050", it'd be cheap, and yet a great street package using mostly stock parts.
|04-23-2009 03:53 PM|
rebuild the block stock with hyper pistons. no need to balance or knife edge or arp bolts or 0 deck or line bore.
use a piston that makes 9.5 to 9.75:1 cr with 64cc heads.
get a set of 180cc darts or afrs with 64cc chambers.
use an edelbrock rpm intake with a holley 750 3310
1-5/8 long tube headers, x pipe, 2-1/2 pipe with dynomax super turbos
The above set-up will work well with a close ratio 4 speed with a 3.55 gear
or a wide ratio with a 3.36 gear.
use zddp oil additive at each oil change ( www.zddplus.com )
Install a 3.75 stroke and make 17% more power over the 3.25 stroke. That is like a free 60hp shot of n02.
for long highway trips, use 9 to 9.25:1 cr, compcam 260H, 3.08 gear, and a wide ratio 4 speed.
|04-23-2009 03:52 PM|
|04-23-2009 11:40 AM|
|American Muscle||Hey 1968 it seems like your dishing out alot of cash on this motor to be currently out of work. It must be nice.|
|04-23-2009 11:11 AM|
|04-22-2009 09:59 PM|
i love this quote "horsepower sell cars but torque wins races"
i would listen to these two guys they have already proven them selves on this site time and time again of thier knowlege
just a question from me, with him wanting his pistons to go just above the deck @ TDC, wouldn't his CR be rather high and be in possible danger of hitting the valves before they close + plus posibly hitting the heads and the higher RPM he wants to run?
i could be wrong
|04-22-2009 09:27 PM|
Ok, mr. experience tell me your the genius and I`m the moron by pointing it out so many ways when you have no idea of what my experiences are.
When it comes to anything experience is the key. I`ve met I don`t know how many ASE certified mechanics that didn`t know the difference in a carb and fuel injection. There is no substitute for experience. Now, explain to me why your asking the question again? If your experience is that great you don`t need me or any other of this site to answer your question. So since you want to play with me in terms of NASCAR engines and street engines go ahead, I look forward to this. I look as you as another guy that believes everything he`s told and he can use a NASCAR engine in a daily driver. Funny, I never seen a street engine operate at 6000 to 9000 RPM.
|04-22-2009 08:13 PM|
I would go with 6" rods for a few other reason, but the rod ratio creating power is not realy one of them. Running 6" rods in a 327 with 10.5:1 compression with some nice 190ccish aluminum heads will definitely be a street brawler- don't forget the valvetrain, cam, intak, carb, exhaust, trans, and rear end to match though.
If you're racing stoplights a 383" engine will be a much better choice though, as torque does rule the streets and there's no eplacement for displacement.
As to turbo's, I feel that its no longer a ricer thing- sure there are ricer posers but there are also stock looking Ford Focuses running 350 to the wheels on pump gas- just a shame its to the wrong wheels. And I brought up the Focus thing bcause I'm looking at buying a 2002 ZX5.
|04-22-2009 08:07 PM|
Not sure if you're a Nascar fan or not Doublevision but look at what they do with 358 cubic inches? 800-900 horsepower?, no blower, turbo or NOS. They do it by using small journals, long rods, high RPM. They pay close attention to tolerances, coating and finishes etc.
I know I am comparing "apples to oranges" but there is something to be said for things like bearing speed, oil control, rod/stroke ratio etc. I only have the budget to do this ONCE so attention to detail to help the motor live is important. I would rather spend a little more on the "blueprinting" and detail work to the shortblock than build it all over again after picking it up off the asphalt.
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