406 vs 421 sbc for boost specs forum Whether you’re a seasoned gearhead or just starting your journey into engine building, this guide will provide you with essential tips, parts recommendations, and tuning advice to help you achieve your goal. if you want to go all out with a dart or world block, i'd probably still say leave it at a factory bore, whatever it will clean up to, then throw in a 4. there really is no reason to knock more bore out of a motor that Dec 2, 2007 路 Hey you guy'sI built a small block 406 for my "73". Sep 2, 2009 路 383 or 406 small block I currently building a 406 with a 4340 forged scat rotating assembly and a set of 195 AFR heads. C3 Tech/Performance - 406, 415, 421 or a 434 Stroker - What do you guys think? I have a 511 4-bolt block being cleaned/mag'd & pressure checked. ,Yes Joe I know it's a cam for girls. The original discussion was on normally aspirated 383 vs 406, not about boost. 23 compression with the Fel-Pro . You will need more cam than you have to turn 6000 rpm. Apr 2, 2010 路 if youve got a 400 block you currently tend to build a 406 vs a 377 , the 377 used to be the better choice simply because in the past the only source for heads was ported O. 420 lobe I can get away with a 1. My first go around with a 406 was a full second faster than my 355. If you end up going with the 400, I would recommend going with a dart block for $1500 it is hard to beat! as briefly mentioned you can make a 406/421/434, etc out of it and creep into the 600hp range. Anyway I’m starting fresh with this 421 and the heads are not returnable because they were installed. I originally intended them for my fairly stock 406 short block and pulled several head bolts threads, 馃槩. I got the DART SHP block 31161211 thru summit racing on special financing. so buying them and sending them back to doug herbert takes some time. 072" head gasket,TFS twisted valve 13Deg intake with a 62cc Username Post: 421 sbc (Topic#332719); 498 chevy "15th Year" Platinum Supporting Member Posts: 527 Age: 73 Loc: hayward ca. All the 421's I have built I have used a solid roller and have gone to the . BTW, hydroboost is awesome on boosted engines. 57 spring, and then to high tech stainless, which comp said would clear a 1. . Mar 3, 2009 路 i don;t have a block yet, and mike i blew up my comp ultra golds, and didn;t wanna go back to them. Apr 12, 2008 路 Best ET 10. 600 lift, cut on 108 L/S. Vic Jr intake with port matching and minor plenum blending Quality machine work. Since the bbc looked so cool in the car, it got replaqced by a 548 Big M'd monster that now runs 9. Mar 7, 2012 路 Here are the dyno results of my 406 build: 406 SBC, AFR 210 heads, 13. Peak TQ with 1 7/8 headers was 544. 2 compression, Holley Strip Dominator intake topped with a 1" HVH super sucker spacer, Cam Motion cam (Duration @. casting, based cylinder heads, being available that could not effectively flow enough air to feed a 406 spinning up at 6500rpm, but in the last 20 years aftermarket Feb 1, 2018 路 Overview Building a high-performance 421 cubic inch small-block Chevrolet (SBC) engine that produces 700 horsepower is no small feat. So far with a . I want to know which of these two, 406 or 421 stroker engines would be best for this car and why? The car will be a dd/street rod. Dec 1, 2021 路 Hello there. I’m interested in hearing your view and arguments of what heads to go for, around the price bracket mentioned above, likewise what intake to match it with. Engine Specifications Before diving into the build Mar 4, 2009 路 Hey guys! Will a afr 210/76 heads be compatible with a 10-10. 5 to 1 comp, 220cc heads, and a 250-ish duration hyd roller made 640. Nice that a smaller head can do almost the same. I'm sure abit more head, more rpm with more cam can get near 700. in. I dont think that would break the bank too bad. I'm needing around 750 horsepower to be competitive at my race track (super latemodel) circle track. Apr 5, 2011 路 i would run the 406 for shorter stroke than the 421 that way you can get a better piston built that way you can put some boost in it . I agree that boost is a great equalizer but it's not free or easy. 12 months NO INTEREST plus tax-free. 000 base circle cam using a Callies rotator using the compstar rods. Aug 11, 2011 路 There was a few street pump gas motors posted around here or chevelles. 5:1 pump gas 434 sbc? or will a 421 sbc be more suitable? These are the race ready version heads, im putting in a 69 caprice! Apr 7, 2011 路 Go for a hyd roller cam, you're specs will be fine, although I prefer a tighter lobe separation. It will go in a swb Chevy stepside. The sbc wins, hands down. 39 on motor. upgraded to pro magnums, that didn;t clear my 1. Reg: 09-28-07 Mar 15, 2012 路 C3 Tech/Performance - 383 vs 400 sbc - I built a 383 with hydraulic lifters, flat tappet cam, and vortec heads last fall. 050 on the intake side and 260 on the exhaust side, . Dec 13, 2009 路 Hypothetically speaking if you have a 496bbc built for boost, a good roller cam, a set of dart heads (in proportion to the cubic inch)9. Is there a better head for this application? Feb 9, 2012 路 A 383 has a 400 crank as you know. I recently purchased AFR heads, 195 street port. 06 in the same car after repeated attempts to best the small block including jet changes, converter changes and two different intakes(?). 00" stroke crank. I'll let you decide if it's worth it. 904 lifters because of the smaller base circle cams. 57. Should be an easy 550 HP piece that will be anvil reliable and need nothing more than a quality synthetic oil change at regular intervals. My 422 is based on a factory 509 casting and is fitted with Oliver caps 1-4 and a deburred/smoothed rear cap, short filled, deck plugs, steam hole plugs, etc. 8cc Dome Pistons, 2-PC Rear Seal, Performance Rings and Bearings Included Learn More Jun 25, 2007 路 Everyone knows that power adders like boost or nitrous make big gains, but claiming small engines are better than large engines and leaving out the boost part is deceptive. Jan 25, 2020 路 A note that big boost numbers will get you into steel O rings and copper head gaskets pretty quickly. Apr 14, 2011 路 Looks like runner of about 210 – 225 should be sufficient for a 406 – 421 (depending if I stroke or not). E. Feb 20, 2006 路 If you're building a motor to a power/rpm level that will require splayed caps on a factory block, just step up to an aftermarket block now. Best results with 36* timing. I am now entertaining the thought of another build. 406 with 11. As far as overheating built right with sensible stuff they run great. The cu in difference would be worth about 22 lb ft of torque, all else considered. Jul 21, 2011 路 I have 4,244 lb 1976 chevy caprice with a stock sbc 400 in it. The SBC with boost has an appetite for the center cylinder head gasket, very serious boost requires a lot of attention to cooling the adjacent exhaust valves which is the principle cause of trouble with the head gasket. 65 that didn;t clear my 1. 708/. As per Lingenfelters SBC book "why build a 383 when you can build a 406" (,030 over 400) for the same money and get 23+ cu. Feb 17, 2020 路 Ok I have already a lil m dart block I'm no mechanic so I'm reaching out to you guys to get all the specs needed as this has been a hard topic to find information on, there is limited stuff on YouTube or google on building a 421 sbc. 646, LSA 110), 950 HP E85 carb, 1 3/4 headers. Aug 28, 2010 路 its hard to find a good old 400 sbc such as 509/511 castings. 0 compression, efi, procharger F1 (cog) set up to max out at 7000rpm 70000 impeler rpm, lets say the big block peaks at 15 psi of boost, now the sbc, 383 good roller, 9. I started building the 383 stroker and mid stream changed it for the bigger cubes. I've got a complete small block Chevy top end off an engine that I threw a rod through. Dec 20, 2018 路 General Q & A - 406 / 421 sbc builds - Anyone care to share their build experiences with a 400 small block chevy? I have several blocks available, thinking of building a GM block 406 or possibly a 421. May 14, 2020 路 Just doing the math, compression is worth about 2% per point. Small Block Chevy 415/421 Rotating Assembly Kit, Eagle 4340 Forged Steel Crankshaft, 3. Two big blocks to beat one small block. Peak HP was 596. 875 Stroke, 400 Main, Eagle 6. M. Two bolt,cast crank,ARP stud kit with Moroso windage tray,polished and peened pink forged Chevy rods,clevite bearings,weisco pistons,press pins,Comp roller cam 565"/289 /112 center line ,intake,11. 5 ratio Apr 20, 2012 路 The 421 seems very popular now and the 220 AFR's would be the way to go. com that made mid high 600's with hydraulic rollers. The 406 there was under 9K. 050 263/273, Lift . I plan to go forged lower end and it will be going into a 77. Feb 9, 2012 路 A 383 has a 400 crank as you know. Re: Anyone do a 406 to 421 SBC comparison? Results? Worth the change? by RevTheory » Fri May 15, 2020 10:22 am. Nov 26, 2021 路 I am building a 421 sbc with a short block from Ohio crank. Apr 6, 2011 路 421 SBC. Hyd. The bigger engine will be faster, and it will be turning more rpm at the finish line. 030, absolutely use torqueplates, and leave it at 406. 421 is a good n/a and nitrous . I did it on a limited budget so it is by no means a high performance engine but it was a definite improvement over the crate 350 that the PO had in it. A 421 needs a stroker crank which costs money. 0,dart heads, again to match the cubes Aug 7, 2003 路 my opinion, if you have a factory block, just bore it . Jul 20, 2013 路 Put together a 421 recently with cam specs almost identical with ported RHS 235 heads and had similar results. Jan 14, 2020 路 It will pull to 6900 crossing the finish line, but the big cube small block needs good heads. 000 H-Beam Rods, JE 2618 Forged +10. roller cam with 255 at . Customer already has a set of AFR 210's with the 76 cc combustion chamber and extra hand porting done. The parts I have include •AFR 220 Eliminators, 1110 competition ported heads, 8027 spring upgrade, titanium retainers, 65cc •Crower stainless steel full roller rockers, 1. rlkju vvhiowq tav iviebiy ctydaf shef ggdue xygyj bqrgoid wghjltmmh