|09-09-2003 10:35 PM|
going back to the earlier 1.6 ratio question:
the 1.6 ratio effectively fools the engine into thinking that the cam has more lift because it opens the valve 1.6 times as much instead of 1.5. Make sure you get a set of springs that will be able to compress to this added lift.
|09-09-2003 06:14 PM|
|ThaBIGJerm||With out any extensive machining, I should stick w/factory length rods shouldn't I? I was originally going to go with a speed-o-motive 415cid stroker kit, but the man at the machine shop recommended that I use the factory crank with a good set of rods and pistons|
|09-09-2003 04:36 PM|
|gt2betubbed||Well the different rod lengths are for exactly what you said, more torque and power. They are usually combined with stroker cranks which add cubic inches which makes more power. And that's what it's all about...MORE POWER!!!!|
|09-09-2003 04:11 PM|
|ThaBIGJerm||Thanks alot. I'll probably just go with a cheap set from summit. Next thing...what in the world is the big difference with the different rod lengths? Factory is 5.565" and then you have 5.7 and 6". I could see where a longer rod would help with leverage and make more torque, but the length is evened out by the pin placement on the pistons...if I'm not mistaken. Next on the agenda will be gearing. I just want opinions on this though, I don't plan on changing anything because I think w/all the torque down low and across the band that it won't hurt too bad. O.K., here it is...are you ready...2.73. Yeah I know!! The car likes interstate driving.|
|09-09-2003 03:59 PM|
Sounds like you are on the right track.
As for the rocker ratios, the best way to tell is by trying them. There's no real way to tell if there's a benifit from them because almost every engine acts differently with them. Why this is, I don't know. See if anyone you know has a set that you could try out before you spend some money on a set. Although, if you don't have roller rockers already, and are considering buying a set, I would go with the 1.6's. I've never heard of them hurting performance too much...
|09-09-2003 03:49 PM|
|ThaBIGJerm||Thanks. I've already got an edelbrock performer intake and I'm selling it to replace it with a performer rpm. I was going to order a road demon carb...probably a 625cfm. As far as the heads, factory is junk and I know a fella with some early 90's vette heads but I want the casting number before I shell out $700. They've already been reworked...new springs, valves, locks, etc. If not, I work for a GM spin-off (Guide Corp.) so I get the vortec heads at a pretty good price. I'll just have the steamholes drilled at the local machine shop. Next question...how much will 1.6 roller rockers help or will it hurt for what I'm aiming for. And by the way, I'm going for some good bottom end grunt and mid-range hp.|
|09-08-2003 08:11 PM|
|jrhoss||hows it going, some suggestions for your 400. go with a flatop 4 valve relief piston, idealy a hypereutectic. durable at a good cost the cylinder heads should be 76 ish chambers older style 920's 336's etc. try to stay in that range smaller chambers will put more heat into an already warm running engine. edelbrock performer rpm intakes work well from1800 to 55-5800 rpm right where that motor wants to be. lastly a 600 holley will work well but if you have limited tuning skills a 600 edelbrock is good for no hassle driveability. ps dont worry about the steamholes just buy the black fel pro gasket|
|09-08-2003 07:45 PM|
If your running an aftermarket cam, it's usually a good idea to have the heads redone, but I won't harp to much on that, cause I'm not
A set of headers and an aftermarket intake manifold will help it breath better so your cam will actually have air to move in and out. A Quadrajet should flow alright for your application, but just make sure it's adjusted to your application (change after the cam break in period, it should atleast be able to run at 2000+ rpm for 30 min as it is, if you mess around with it now, you could have problems)
|09-08-2003 07:09 PM|
|mikeweyman||be nice if you can find some vortec heads and intake. 1995 and newer 5.7 litre chev pick ups have the vortec heads.but you'll need to change the intake , maybe a 680 d.p. holley carb,a set of headers , and , sweet. if not, a good set of 882 heads will do nice for the street if you clean them up a bit with the die grinderand go 202/160 . it will pull you back in your seat a bit too.----- mike .|
|09-08-2003 07:03 PM|
|bowtieorbust||That (ex-4x4 262) has a 111. lobe sep.to it,the (ex-262)has a 110.lobe sep,just incase you didnt know.What's your intended use for the car?|
|09-08-2003 06:54 PM|
|ThaBIGJerm||Chevy 2-bolt main|
|09-08-2003 06:47 PM|
|bowtieorbust||Is your 400s/b a chevy or a pontiac engine?|
|09-08-2003 06:17 PM|
Thanks, but I'm not concerned about the tranny. It's a 700r-4 and will bolt right on up. I was more concerned with what heads and intake I should run in order to make the combination match...on top of not wanting to spend a small fortune. If anybody has any suggestions or full engine combos already written up, it would be a big help.
|09-08-2003 12:01 AM|
You may need an adapter plate to mate the engine to the transmission. PAW (Performance Automotive Warehouse) sells the adapter plate. You may be lucky enough to have the dual pattern bellhousing. You can tell those ones from the others because of the extra bellhousing bolt holes. I would check first before trying to lower the engine in place and finding out the hard way.
Other than that just remeber that the 400 is externally balanced so make sure you have the externally balanced, balancer and flywheel combo.
|09-07-2003 11:42 PM|
Hello there. I'm new to the site and figured I'd check to see what I could learn here. I've got a sbc 400 that I've decided to build to put in my wife's Firebird. It's going .030" over and the cam I'm using has a lift of .462"I and .480"L...the duration is 218/226@.050". It's actually a comp cams 4x4 xtreme energy cam but it works for what I'm aiming for...torque. My question is, or questions are...what else do I need to bolt to this puppy based on the cam/engine. Heads, intake, compression ratio, etc.?