HOW TO: MAKE SBC POWER WITH BASIC BOLT ONS (305, 327 & 350)

here and welcome to the channel today it's all about small blockx Chevy bolt-on performance in this video we're going to take a look at how the small block Chevy responds to typical bolt-on performance we're talking about cylinder heads cam shafts and intake manifolds on three different combinations a 305 a 327 and a 350 so how do they respond let's find out we're going to start off with our Trio of mild performance small blocks with actually a 305 I know that I'm going to get a lot of comments about the 305 oh that's the worst motor that Chevy ever made but this one actually started out as a comparison I did between the 5 L 305 and the 5 L 302 from the 80s and early 90s on the Ford side and it's interesting that a lot of guys would take oh the 302 makes a lot more power because even though they're both five lers and one is three cubic inches less than the other everybody likes the Ford better because it has a 4-in bore so the much maligned 305 Chevy everyone say says oh that's a terrible motor just get a 350 but the 305 uh Chevy actually works pretty well and can be made to to have a lot of power the one thing I can say about the Ford Chevy combination or about the Rivalry obviously Camaro Mustang it goes way back but in the case of the 302 versus the 305 ultimately I think that the 302 Chevy or Ford has a little bit of an edge only because it has more cylinder heads to choose from the small bore 305 is kind of limited although in this case we were nowhere near using up all of the flow that was available from the trickflow 175 heads that we used on the 305 that being said on the 302 Ford there are 20 or 30 or 40 different cylinder heads that you could use on the 302 Ford and because it has a 4in board there's lots of heads and there's and the heads have even more airf flow and even more power potential than the limited heads that are available for the 305 but that doesn't stop me from liking this motor and there's lots of them out out there in back in the day when they were in the Camaro these z28s and iro and stuff they actually ran fairly well and this was actually started out as a low mileage or no mileage 2.5 L 305 so when it was Stock It produced 267 horsepower and 333 foot- PBS of torque this thing was run with long tube headers and and Open Exhaust a miser electric water pump and no accessories we ran a cold we ran with a holly HP management system it did have the stock throttle body and stock tune port and stock heads and all of that but this was actually a very low mileage motor that we got from the guys or the GU from westch got from the Chevy race shop so this thing might have had no miles on it actually might have been a time capsule one that came off of the assembly line and then was put in the Chevy race shop and they ended up doing nothing with it probably and then the guys from westtech got it and then I got my hands on it and took it all apart and ruin probably what was a perfectly good Tom Port 305 but what we did was in our comparison between the 305 and the 302 Ford we equipped them both with basically heads Cam and intake manifold so in this case we replaced the factory heads with the trickflow heads so they were the uh trickflow super 23 175 heads uh 56 CC Chambers 175cc intakes and and 6 60 7 CC exhaust they had a 194 and 150 valve package so they would fit nicely in the small boore of the 305 we put a comp extreme energy 276 hydraulic roller cam in it this came as a factory hydraulic roller it was a 224 230 at 50 and 110 and a 502 510 lift split we also put a we replaced the toun port injection system with a simple carburated induction system like this you know like you put on most small blocks it had an RPM an ed Rock RPM air gap intake manifold the Dual plane and a 650 Holly XP again it already had headers and and an MSD distributor so equipped with the Dual plane Peak power jumped up to 363 horsepower and Peak torque was at 353 foot-pounds now we did another test on this and I don't think it's quite as good a combination but since we're always doing the single plane versus the Dual plane stuff we ran that comparison on this 305 and indeed the single plane did make more power made 376 horsepower and the peak torque checked in at 347 foot PBS but happened at a much higher engine speed than the Dual plane and as you can see from about 5,300 RPM on down the single plane made less power than the Dual plane on the 305 so now that Tak a look at a 5 L 305 let's jump up to a 327 this second small block might not be as popular or prevalent as the 5 L 305 or the other 350 that's kind of the go-to displacement for small block Chevys but the 327 was very popular it it liked rev and made good power this particular example started out as a very impressive one it was a 365 horse 327 reproduction motor that I did back in the day and this thing was equipped with 11 to1 compression fuy heads the good dun cam shaft the Dual plane intake it originally came with a 780 Holly but we put a 750 on it and it had long tube headers and equipped in this manner it was already starting off making fairly good power 355 horsepower and we ran this thing all the way out to 8,000 RPM and 366t pounds of torque the important thing is you'll notice that it made more torque than horsepower and that tells us gives an indication that this thing is being held back by something in this case it's probably the cylinder heads the ham shaft can make a bit more power it has a lot of duration it has a good intake manifold and carburetor on it the fely heads could make a little more power than this but what we did was basically change almost everything so what we did was add a new cam shaft to this combination it was a comp uh extreme energy still a solid flat tapping cam it was an XS 274 s which was a 501 510 lift so much more lift than the dof cam it was a 236 242 degree duration split even though it had that had that was less duration than the donop cam and 110° lob separation angle we also replaced the fely heads with the set of airflow research l98 heads and then the uh aluminum heads obviously aluminum over iron but also flowed way more than the you know as much as 70 or 80 CFM more than the than the best fuy heads we ran an aftermarket intake manifold although we could have also run the factory one but we ran a Speedmaster dual plane high-rise intake manifold and a 750 Holly just like with the last one and here's what happened when we ran the Dual plane power was up dramatically 441 horsepower and 407 foot pounds of torque so now you'll notice that we're making much more horsepower than torque which gives us an idea that hey now the combination is actually working fairly well but just like with the 305 we also ran a single plane intake on this and given the fact that we were running the 7,000 RPM we thought that the single plane might eek out the Dual plane and make more power Fair a fairly good portion of the RPM range and that's exactly what happened with the single plane it made 461 horsepower Peak torque checked in at 412 foot pound so actually just Eed out the Dual plane for Peak torque but as you can see from about 5,000 RPM down the Dual dual plane made more torque made more power but from 5,000 RPM up the single plane made more power so again you always have to choose which one you want do you want more power below that point or more power above that point honestly if I was going to have a 7,000 RPM uh 327 I probably would have the single play on this now we can take a look at a 350 the final of our Trio of mild Performance Small Block combinations was a 350 and despite being the largest displacement it actually made the least amount of horsepower of the three including the including the smaller 5 ler combination and the reason is that it was saddled with a two barrel induction system we did run long tube headers on it but it basically was stock it had a good short block it actually had forg Flatt top pistons the reason that we chose that is because we were eventually going to do a lot of modifications in fact of all the small block testing that I've done this series was probably my favorite because I did so many different steps we ran so many different different combinations with this thing we ran it all the way up to where this thing made some very serious power with the hydraulic roller cam and big heads and the intake manifold and all that stuff but along the way we got to test a lot of stuff including two barrel induction systems and headers and stock heads and ported stock heads and a variety of different cams and stuff so it was very cool but starting out on this 350 with stock 882 heads it did have flat top pistons in it it had a stock 180 or 19 horsepower Truck cam in it that we got from a local auto part store it it had a two barrel cast iron intake manifold with a two barrel rodchester 2G carburetor it did have long tube headers on it and run in this manner the 350 managed to produce a whopping 247.25001 fairly constant down in that low RPM range so 350 in motor makes fairly good torque but here's the first combination that we ran and the power was up pretty dramatically 364 horsepower and more importantly 422 foot PBS as you can see it was over 400 foot PBS for quite a ways and this was a fairly simple combination it's the one of my favorites because it's something that anybody could duplicate we had a fairly small cam shaft in this it was still a hydraulic cam shaft it was a uh a pure energy 246 cam so basically top of the page the smallest um aftermarket Cam that comp offered for a small black Chevy so it was very tiny and I'll go ahead and put the specs up there so that you can see it but any Cam that has a 20 something duration cam shaft is pretty small it idles like a stock one it runs very well but it makes it makes good power I've run that cam shaft in a back toback test against Do cams and it picks up quite a bit of power despite the fact that it would have been considered an old RV cam let's say we also had an RPM um intake manifold on here with the with the Dual plane with a dual plane intake or the Dual plane intake manifold and the 650 Demon carburetor to go along with and the other thing the other change that we made in addition to the cam shaft was we took the 8882 heads and had them ported um and that not not radical but mildly ported Port match did a little bit of B work the kind that you would do if you did it yourself at home and the combination worked out very well as you can see you know not a huge Peak Power number but very good torque and very good average power production so this combination worked fairly well we did step up from there with a set of aftermarket heads in this case they were Holly 23° aluminum heads we put a a an extreme energy 268 cam in so a much more modern cam design a little bit more aggressive again like with the Pure Energy I'll go ahead and put the specs up here for the the comp extreme energy that we use we use an RPM air gap intake manifold and again with the 650 carburetor and so equi that combination produced 419 horsepower and torque was up basically everywhere 444 foot- pounds of torque and you can see at least at wide open throttle this combination worked very well it made the same torque even down at 2400 or 2500 as the milder combination did it's just that the extra cam shaft and extra breathing from the cylinder heads and a good dual plane intake manifold and the right carburetor all combined to make this combination work very very well in this RPM range and it made Peak power out at 55 or 5600 and carried all the way out to 6,000 so it has a good broad power range nice little small block let's get to our conclusion okay guys what do we learn from this little adventure with bolt-on performance parts for our small block Chevy well in typical fashion every small block responds to bolt-on Performance from the lowly 265 all the way up to the gigantic relatively speaking 400 in small block and every motor in between including the much maligned 305 obviously the 350 and the one in the middle the 327 they all correspond to bolt-on Performance if you improve the head flow the cam timing and the induction system good things are going to happen to your a small block Chevy Armature holder please make sure to like share subscribe ring the bell do all that stuff more and more testing coming up

Channel: Richard Holdener

Views: 138,749

Keywords: HOW TO MAKE MORE POWER, SBC PERFORMANCE MODIFICATIONS, SMALL BLOCK CHEVY, 305 CHEVY, 327 CHEVY, 350 CHEVY, AFR HEADS, HOLLEY PERFORMANCE, COMP CAMS, LONG TUBE HEADERS

Id: kJ_zoQhfidI

Length: 13min 45sec (825 seconds)

Published: Sat Aug 14 2021