jay173

I was doing some heavy research and found this:

http://www.darklair.com/monte/400hp305.html


Is this article valid and can it still be done?


How expensive would it be to build a 305 like this now days?

MC305SS

I think either something is missing in this or whatever.
I am now looking for further info and trying to build a 305 with more torque than horsepower if possible and the things this build has mine doesn't is the cam and heads.
And from other articles done that I have read this combo wouldn't hit that number nor rev that high I believe.

Apeiron

I'm sure it's real, there's never been a question that a 305 can make 400 HP. Notice that they spin it at 7500 RPM to make 400 HP, but a 350 might make 400 HP at only 5500 RPM. Their peak torque is also only 344 ft-lbs, but a 350 could make maybe 425 ft-lbs. That makes the larger engine more better for the street.

MC305SS

A 305 can spin that high on what looks to be stock internal parts??

8t2 z-chev

Not for long-i remember another 305 buildup done
around 1982 that i read that also got about 400 hp
at over 7000 rpm in which a stock cast piston blew
With forged pistons probably would have lasted a little
longer
If i find that buildup again,i will post the details....

FueledSoul

iTrader: (18)

Its real, no doubt its real there is no magic to it. They respond to mods just as any other engine would. There have been many 305 build ups and the most recent artic is this one http://www.popularhotrodding.com/eng...cks/index.html
There are 305 sprint series races cars that are pushing 500hp with huge limitations just read these engine rules http://www.midwest305sprintcars.com/rules.pdf. As far as what others have said any engine can spin high on stock internal parts as far as how long it will last that all depends. At 7000 rpm your **** to detonation and valve float its no surprise that the cast piston shattered but even switching to forged would be no real benefit especially if there still using stock rods and rod bolts. In theory if you had a 350 and a 305 with identical components the 305 will make (give or take) 30 ft-lbs of TQ less then that of the 350 and somewhere around 10 to 20 less hp. obviously this is just a theory.

No different then a 350. It all depends on what you want to do and how much you wanna spend.

Doom86

That build is a joke they could have made that power at a much lower RPM. I would love to talk to the clowns that put that together.

Look around there's guys on this board who've built 400hp 305's that do there thing at 6-6.5k RPM.

FueledSoul

iTrader: (18)

The articles from 1983 technology and parts have improved since then. On top of that L69's are flat tappet blocks, lobe profiles are less aggressive.

Guest

I still dont understand why people get all excited over 305 builds. Build an identical 350, you'll get more power. Build a 305 instead of a 350 combo, you'll get that much less power. If copying a 500HP 350 build in a 305 and making 435HP instead excites you, then by all means go right ahead.

That motor is probably your typical dyno queen. They also have the RWHP, and it was likely rounded off as "300" at 7k RPM. If you do some simple math, they ended up with a 24% drivetrain loss on a stick shift car. What that means is the motor as tested on the engine dyno had... maybe a water pump. So consume a few grains of salt, and then read the results.

Doom86

No doubt you could do much better then, that was nearly 30 years ago a LOT has changed in the SBC world.

Doom86

I still dont understand why people get all excited over 350 builds. Build an identical 400, you'll get more power. Build a 350 instead of a 400 combo, you'll get that much less power.

Everyone doesn't do this to fill some empty illusion of success putting a bigger bore in gives. There's always something bigger and better you could do.

Some of us do it because building motors is fun and we enjoy doing it.

Apeiron

350s aren't exciting, just cost-effective.

Doom86

Maybe a rebuild yes it cost less to rebuild but 305's are a dime a dozen so the core being free may offset that a bit. And while we're splitting hair what about the fuel mileage savings you get while not "being awesome" in city traffic?

If you put forth an once of effort you could find a better core then a 350.

Just build something and have fun doing it is all I'm saying.

Guest

And every single time this subject rears its ugly head, it all goes in the same direction. People claiming things about making as much power as a 350. What 350 is that? The stock one from GM? I read articles like this one and I dont say "Wow, 400HP from a 305!" as if I thought that there was some sort of hard limit on how much power a 305 can make, or if I thought that there was some inherent magic to a 305 that a 350 cant attain. Its all nonsense. The most cost effective builds are 350's, because just about any head out there fits with no issues, the internal parts are the cheapest because the 4" bore 350 motor is the most common one GM ever made, and they make a good amount of power at a reasonable RPM. If you want to build a 305, fine. Go ahead. If you want to claim there are advantages to doing so, you're just deluding yourself.

This particular build is using a 244 (not 224) duration on the intake side. That, in a 305, is going to be anything but friendly to drive. Copying it would be a mistake unless you're only trying to build a temperamental race motor. If thats the case, 400HP at the crank is a pretty sorry number.

Guest

Fuel mileage savings? ROFL. Yeah, a 244 intake duration and 650CFM carb is going to do wonders for fuel mileage.

Doom86

The only advantage a 305 has on a 350 the way I see it is they are dirt cheap, people give them away in running condition.

yep the fuel mileage was a joke, just like the 305 the OP posted is a joke. Neither should be taken seriously. But hey if you are getting all emotional over spending 20$ more for pistons spending that much more in gas on a weekly basis to be way more awesomer then me should be considered.

MC305SS

I'd like to make a comment here if allowed.
350 blocks in the shape of my 305 here would run me $350-$500.
More times than not these will either not have heads or have a poor set of heads.
Cost prohibitive for me will be around $2K for a 300++ 305.
Now a 350 needing some heads and costing me that 350-500 range to start then paying for head would then be not cost effective.
This is where one would look to get a crate, which just about everyone I see has, its not different and crates at this low end price won't be anymore powerful than the 305 I started with free.

Like stated eariler, why settle for a 350 then. I can get a 400 small block, 396 big block for just a hundred or so more than a 350 block and have much more potential.
See this can be never ending depending on how you look at it. Budget, being different, numbers matching are the decision makers not block size for some!!!

Doom86

That's exactly how I feel and why I try to just have fun with it. There's always something either bigger, faster, more cost effective, or better for some other shape or reason.

If someone could just nail down the equation for success and make it a sticky so we can all find out if we're having fun with this it would be great. I thought I was but who knows.

This build is bad though, it's REAL bad. Wrong heads, wrong cam, wrong people building, wrong time, too little info, ect.

I bet it ran like complete **** tbh, but people don't sell magazines if they tell you that. It would have peaked the same with much less duration at a lower RPM I would bet, all theory given no one's going to waste time reproducing this blunder.

Air_Adam

To build an engine that will survive that power level and those RPMs for any length of time requires some very good internals... those are relatively cheap for a 350, but if they even make them at all for a 305 then they are expensive. You can use an aftermarket 350 crank, but it would need rebalancing to work in the 305. High quality forged pistons for a 305 are going to be expensive compared to the same for a 350. Rods are the same of course.

...that said, there goes the $150 you saved by using your free 305 core instead of buying the 350 core - plus alot more. And you'll be short on power compared to the 350 built with the same parts anyway.

Irockz

iTrader: (1)

I have a shop full of 350 blocks I need to haul to wherever you are,$150-$200 is the absolute most I have ever gotten from a 350 block,$350-$400 for a complete,good running engine.
Why settle for a 350?Because 400 blocks DO bring a LOT more money,are very prone to cracking when max power potential is reached,and most that you find these days have already had all the boring done to them that they can withstand.
The fact remains,the 350 has the most hp/dollar potential of any entry level engine.If you want to be different,build the 350 and swear it's a 305.

FueledSoul

iTrader: (18)

FueledSoul

iTrader: (18)

i don't get why the 400 blocks keep getting brought up, there isn't enough block filler to keep them from cracking lol

MC305SS

Bring them on!!!
Any newer 5.7 yields $750+ running.
Older junk yard 350's which are in need of a complete rebuild are what I posted.
400's are within the same range since they are not popular here by any means.
Big Blocks, rare, but the same price range.
We have over 10 machine/engine shops here which I think eat up any good blocks driving prices up within a 25 mile range. Alot of circle track racers in many forms are here.
Crate engines are the norm here and few build their own up.

89_RS

As long as the 350 crank is a one-piece RMS, internal balance crank it'll work in a 305 without any mods. As long as the rods are 5.7" they'll work in a 305 without any mods. The only thing you go out of pocket alot for are good pistons. Theres maybe 5 sets of pistons offered that are meant for that high rpm.

Eagle makes rebuild kits for the 305 and 350 and the only difference between them are the piston sizes. They both cost $740. The crank, rods, bearings, bolts, wrist pins, and rings are all the same.

http://www.summitracing.com/parts/ESP-13202L000/

http://www.summitracing.com/parts/ESP-13101L/

I've been reading David Vizards How to Build SBC's on a budget and hes stated that cast cranks are good to about 6000-6500rpm. So if the max power is at 6000 and its just a fun car, how often are you going to be getting really close to or over that limit?

A 4340 forged crank is about $640, a set of 4340 rods will be about $500, 305 forged pistons will be $500 and 350 forged pistons will be about $400. This is from a search at summit and it shows the price differential to be $100 more expensive to build a 305 with forged internals.

Almost everything made these days for Gen I SBC's will work on a 305 and a 350 without a problem. Will you make more power with your dollars in a 350, yes but probably not enough to warrant the swap. If you've got a 305 already, theres no real reason to not work on it economically speaking. If you're power goals, desires, rules, etc. mandate something other than a 305, chances are you're not just in it for fun anymore.

Air_Adam

There are 1pc and 2pc seal blocks for both the 305 and 350. If the crank is for the same style block, they will interchange BUT still need rebalancing to work properly. As I said, the rods are the same, so upgrade cost of those is the same. Pistons are not. A good set of forged pistons for a 305 will cost noticeably more and will be harder to find than a set of forged pistons for a 350.

Both of those kits you linked to use hyper pistons, which are glorified cast pistons. They are a little better than cast, but you need a forged piston to handle that kind of rpm (7500+). A cast or hyper piston will come apart at that RPM, unless a rod bolt lets go first. In a stock rotating assembly, or one that uses cast crank and pistons, the crank is the last part to fail. Rod bolts fail first, then the rod itself, then the piston, then the crank.

That 4340 crank you mentioned might be a good deal, but you'll have to have it rebalanced for a 305 rotating assembly, as it will be rough-balanced at the factory for a 350, not a 305. The balancing IS different.

Doom86

Very well put.

Getting +400hp out of 305 has been done and documented on TGO alone if you do some searching. One of the good threads was dug up recently even. The "trick" is to build it like you would any other motor to get that power, fully built, carb to oil pan with the proper parts. Good heads is key just like your dream 350 to reach this goal. Fast355's +400hp 305 did it's thing at 6200rpm too, not like the 'tarded 305 in the OP.

What's this anti 400 SBC bs? So we don't like them now too? 400ci SBC are not rare and hold up well to streetable power there's no reason to not build one, it will make much more power then the 350 and the extra cost is gas money equivalent. Anyone who says different probably has a shop full of 350's he needs to sell..

skinny z

I like assembling engines because I enjoy it. However most of the enjoyment comes from the power produced. If we met at a car show and you explained the details that went into your 305, I'd be no less impressed than if it was a 350. I might be quicker at the track, maybe even get better mileage but that we're both enthusiasts is the common bond.
I tend to skip over most 305 builds because other than the practices that go into building a solid rotating assembly, the approach is somewhat different. The amount of cam and cylinder head are unique (more or less) to the smaller cubes. Still I enjoy the science of it.
As for 400's. Having owned a couple (both 25 years ago and recently) and their tendency to split in the cylinder wall has caused me to shy away from the OEM blocks. I even went so far as to write in to Chevy High Performance and ask Kevin McClelland his opinion. The letter appears in the April '05 magazine titled Sonic 400.
To each his own.

89_RS

I understand that. I even pointed it out that pistons for a 305 cost more than those for a 350.

I understand that as well. I also pointed out that if its a just for fun build, you really aren't going to be getting to the point of needing anything other than those kits. Eagle and SCAT both make similar rebuild kits like the ones I posted and they don't rate them for anything much over 6000.

I understand that too. But if you're to the point of needing forged internals, chances are its not a street motor. I understand that the secondary balance on a 350 is different than on a 305, but its not like balancing costs an arm and a leg these days. Someone on here had their entire rotating assembly, crank pulley, harmonic balancer, and flywheel/flexplate balanced and it was under $500. IMO, a balance is required when rebuilding no questions asked. Its cheap insurance for a motor.

I think you and I are both saying the same thing, but its not getting across to one or the other of us. And maybe neither of us as well

Doom86

Now don't take this the wrong way but is it at all possible it could have been avoided with better cooling?

It's funny you mention not being impressed with big power 305's (sounds biased but to each his own) but most people are impressed with the opposite. I can't tell you how many times people have stopped me in parking lots, gas stations, ect, and asked, "is that a three fidty?", and walk away with a look of disappointment like they missed out on something.

The sound fools them all. It sounds nice it must be a 350, right?

There is nothing wrong with a 350 but it's nothing to get all worked up over either. They are "old news" this late in the game. I just scrapped a 2pc "4bolt main" short block because it needed a full rebuild and to me it's not worth the investment when better can be had for cheap. I'll play with one if it's sound bottom end but investing that kind of money into something it needs to be at least a roller block.

skinny z

I think you may have misinterpreted my remark. I WOULD be impressed by anyone's 305 build. ANY build for that matter. That you're involved in the hobby is enough of a common bond for me. I certainly appreciate all your efforts into building what you have.
If you making commentary on my rebuilding my old 2pc 350 as it's not a roller block, I'd long ago made the investment in a retro-fit roller cam. Considering I have the components to get back into a healthy 350 (or 353 as it sits now), the money spent is worth it.
If I had to start all over again, I might rethink the whole Gen 1 thing altogether.
As for the cooling issue, lets just say I've learned my lesson. Engines are not indestructable.

Guest

Typical reasons people want to build a 305, as I stated earlier. If you want to be different, build an Iron Duke.

sofakingdom

iTrader: (1)

Yes it is real.

Professional wrestling is real too.

It's just not what you're led to believe it is.

Same for that article.

Note that the engine that they built, blew up on the dyno.

Note also that if you took the EXACT SAME PARTS, and the EXACT SAME MONEY, and instead did it to a $50 junk 350 core, you'd have come out close to 500 HP before it exploded. Except in real life, you wouldn't even have to spend the same money; pistons for a 350 are cheeeeeeper than for a 305, and everything else is identical.

Think of CID as being like an amplifier for your money. I take xxxx $$$, and yyy CID, multiply them together, and come out with zzz HP. If I take MORE CID, then it takes less $$$ to get the same HP; or, if I take more CID and the same $$$$ I get more HP. Any way you slice it, the MORE CID you can spend your money on, the MORE you will get in return.

Think about it .... $50, 100 HP. There's NO WAY you could make that 305 get ANY added HP, including what they got in the article, ANY cheeeeper than by buying a 350 short block. Cheeeepest and most effective mod you can make to a 305.

Now: explain how, just because what the article did can be done, that it's a good idea, to do with your own money.

IOW, shut up and stop typing on the Internet and go do it. THEN come back and tell us how it is; not, run off at the mouth endlessly about something you know nothing about, trying to tell everybody else who HAS done stuff how you think things work.

FueledSoul

iTrader: (18)

http://www.superchevy.com/technical/...ild/index.html

Doom86

Looks like a stout build there with room for improvement even. But they weren't building for dyno queen numbers it seems, and more geared towards just a simple head and cam swap.

Proper quench felpro 1094 head gasket, speed pro flat tops, intake valve notched in block and a better cam and I imagine it could pick up 40+ hp.

Firebirda7x

I'm looking into just getting mild power out of my 305 cuz to do a proper engine swap, including the machine shop and magnafluxing and prepwork alone I could spend a lot on the 305. On the other hand, spending a lot on the 305 could net me a 350. I think the 305 is a cute little underdog motor and everyone has a 350 in their cars.

I think people understate the true costs of building up a 350...I wouldn't just find a "$50 block" and build it up for cheap...then again I live in New Hampshire.

sofakingdom

iTrader: (1)

Really???

Last time I was up there, there sure were AHELLUVALOTTA rusted-out old trucks sitting around in front of houses and barns. Kinda surprised me in fact; around here they're pretty rare, I have to go ALL THE WAY to the junkyard (at LEAST 2 miles) to see such a pile of em. But then again, that was about 3 months ago; they might have all disappeared since then? Space aliens getting hungry again?

The 305 is an OK motor, on its own, in a vacuum of alternatives. Not great, not even really competitive, but at least OK. If that was the ONLY SBC that there ever was, we'd all be talking about how to tweeeek em up and get every last horsepucker out of em that we could. But.... we don't live in that world. In THIS world, there's this OTHER size of SBC motor, that's even more common than the 305 and an altogether better starting point for a short block build than the 305 has any chance of being, and it bolts RIGHT INTO our cars without any further modfications whatsoever. Because of that, it is just BALD FACED STOOOPID to spend any money whatsoever anywhere below the head gasket on a 305. All that crap about "everyone has one" and all that IS FOR A REASON. Before deciding to be "different" (translation: making excuses for why you just got your a$$ handed to you AGAIN), you should make an effort to UNDERSTAND why things that are so common, are so common. If the 305 was such a great motor with so much potential, comparatively, you'd find AHELLUVALOT less people throwing them in the trash.

Guest

And notice in that car craft article, their "stock" LG4 made 224HP. Just a bit more than the factory rated (and likely accurate) 140-160HP. Might be all that missing stuff from up top and up front. You can downrate their end results accordingly (dont forget both had headers and likely open exhaust) to get a more realistic end result as installed in your car.

I'm sure you could find a set of Vortec heads to port to attain similar results.

Doom86

^^ The same is true for all crank rated dynos right?

I bet you the ported Vortecs could do better, use LS1 valves, 2.00in, 1.55ex and get the volume to 180ccish. With the right gearing and stall that would be a pretty decent car. More gear and stall then you would a 350 of course.

HP is HP it doesn't matter what makes it, anything can be as fast as your wallet allows. The exaggeration on what it cost to do with a 305 is a bit overboard. The "RACE SAVER 305" class is a great example of this. It's plainly stated the class rules are made with economy in mind and they make 550hp with unimpressive heads.

Too much accounting and not enough enthusiasm IMO. It more boils down to not feeling like a sucker in the end for spending so much cash. Walking away from that McDonald's parking lot conversation feeling accomplished.

One thing I never do is do something because "Everyone else does it, it must be right". Because everyone else is responsible for the national IQ bordering retardation.

Guest

Depends on who is doing the testing and how bloated they're trying to make the numbers look. I've seen tests with accessories in place, and mufflers... although those are exceptions rather than the rule. But to be realistic if you built the same thing, put your PS, Alt, AC, etc in place you can deduct accordingly and end up with a 300HP mill and 240-250 at the wheels, quite in line with what I've seen real people get.

Surely the most sensible thing for anyone to do with garbage bottom ends like that one is ditch the factory dished pistons. They didnt mention final CR (not that I saw), but I'm sure it was nothing short of horrible. It would have been better to have a final CR of at least 10:1 with those AL heads on there. 10.5 would probably be closer to ideal.

Doom86

Well damn I need to do something about my Power steering, alt, and water pump so I can pick up 60hp.

It's certainly going to loose some power adding resistance to the crank just like all the other motors dyno'd like this. The end result though was 140hp increase over the base test and that's what counts.

Yea I saw nothing of CR either but the mentioned the gasket was a felpro 305 gasket so not a shim that I know of. Given the limited info you can assume though they ended up with stock low 9cr (maybe less since most peoples 416's measure 55cc).

With the speed pro's, felpro 1094, standard desk height that would yield 10.3cr and perfect .040 quench though.

They re-used the stock timing chain too for what ever reason. Maybe they ran out of sponsors?

Guest

30, 40, 60, whatever. I quick scanned it and didnt read... 359 was it? Anyway. I've seen some guys putting down 270ish so thats probably where this build would fall. On another note I lost a belt while racing and trust me its a lot. Felt like someone hit a button. The timeslip read accordingly.

The CR is likely to be something less than 8.6 since they said thats what they started with. Add the fact those are AL heads and its just a sorry number. I guess if they're reusing things like the timing chain... Heads must have broke the budget.

Firebirda7x

I don't think the 305 is an awesome motor. But it's what I have, and really...a 350 is a bored out 305...it's not some magical engine. The real issue with the 305 is how restricted it is with breathing. A chevy small block is a chevy small block. If you are going to buy one, chances are you are going to rebuild it and then what difference below the heads are you really having aside from cubes over a 305? Yea lots of long-term potential but you aren't jumping drastically. It's all in the cam and heads after all...

But when you already have a 305 in your car, like me, investing in rebuilding a 350 isn't always an immediate option. I will do it eventually but right now I'm going to rebuild my 305. It's fun to drive, and I do like having something a bit different. Everyone told me I should have bought a camaro, but I would be the 20th student with one. Yea yea a 3rd gen Firebird ain't any different but when you like a car, or a motor, it doesn't really matter.

If you want to dump enough money at something, you can make it go fast. 350s just do it cheaper.

FueledSoul

iTrader: (18)

You can not take a 305 block and bore it to a 350. The most you could get from a 305 block would be 345ci using a 3.75 crank and .60 overbore. by that time its just a waste of money.

FueledSoul

iTrader: (18)

Here is some more i ran across

http://www.hioutput.com/tech/290hp/290hp.html

http://www.hioutput.com/tech/343hp/343hp.html

http://www.hioutput.com/tech/400hp/400hp.html

http://www.chevyhiperformance.com/te...ods/index.html

"325 horsepower 305 cid Chevrolet V8
(Built with simple bolt on mods!)
This information is a brief summary of an article that appeared in the March 1999 issue of Car Craft magazine.
305 BUILD-UP PART 1.
Car Craft started out with an 80,000 mile (130,000km) 305 LG4 engine from a 1982 Camaro. They removed the engine from the Camaro and put it straight on the dyno with headers, 3" dual pipes to Flowmaster mufflers, and a HEI distributor with 22 deg total advance. This gave a baseline dyno result of:
197 HP @ 4,000 rpm. 261 ft/lb torque @ 3,100 rpm.
305 BUILD-UP PART 2.
Added an Edelbrock Performer EGR intake manifold, but with the EGR blocked off.
217 HP @ 4,200 rpm. 285 ft/lb torque @ 3,300 rpm.
This is an increase of 20 HP and 24 ft/lbs over stock.
305 BUILD-UP PART 3.
Replaced Edelbrock Performer EGR intake with an Edelbrock Victor Jr single plane intake manifold. Replaced Q-Jet carb with a 750 Holley double pumper.
217 HP @ 4,200 rpm. 285 ft/lb torque @ 3,300 rpm.
This resulted in no change from the previous mods, maintaining the increase of 20 HP and 24 ft/lbs over stock.
305 BUILD-UP PART 4.
Added Comp Cams XE262H-10 "Xtreme Energy" hydraulic flat tappet cam. 218/224 dur @ 0.050, .462/.469 lift, 110 deg LS. Set initial timing to 16 deg BTDC.
270 HP @ 5,100 rpm. 291 ft/lb torque @ 3,800 rpm.
The cam change resulted in a huge increase of 53 HP. Torque was up by 6 ft/lbs.
305 BUILD-UP PART 5.
Replaced stock cylinder heads with World Products 305 S/R Torquer heads.
298 HP @ 5,500 rpm. 308 ft/lb torque @ 3,900 rpm.
A 28 HP increase over the stock heads, and the 305 engine now has close to 300 HP.
305 BUILD-UP PART 6.
Replaced World Products 305 S/R Torquer heads with '96 - '97 Chevy truck L31 Vortec cast iron heads, GM P/N 12558060. These are available from GM dealers in the USA for US $408 a pair, fully assembled. The Vortec heads require a different intake manifold, and Car Craft chose an Edelbrock Super Victor. They kept the same Holley 750 DP. Car Craft says that these heads are a bolt on for conventional small block Chevy engines. If your engine is earlier than '87, you will also need a set of self aligning rocker arms, and a pair of "center-bolt" valve covers.
325 HP @ 5,800 rpm. 317 ft/lb torque @ 4,800 rpm.
TECH COMMENTS
With peak torque at 4,800 rpm, the 325 HP 305 would definitely need some stiff rear end gears (I'd suggest a minimum of 3.73 ratio) plus a high stall converter if the car had auto trans. In my opinion the WP Torquer heads are the better choice for a street engine. I think that a 300HP 305 with 308 ft/lbs at 3,900 rpm, would be a nice street / strip combination."

Doom86

Here's a well notable 305 for you all. Stock bottom end minus ARP rod bolts with standard bore. Made peak 394hp @ 6,300. He made changes for the competition in 2008 and was DQ for an illegal oil pan. Rumored to make 487hp using the same heads though, but no proof I can find other then someone telling me who spoke to him.

I think this guy has the idea but the wrong heads. Even RHS Vortecs with the same valve should have been notably better.

http://www.popularhotrodding.com/eve...e/index11.html (scroll down to the second build)

FueledSoul

iTrader: (18)

And minus the hypereutectic pistons. Interesting how there running 2.00/155 valves with a 1.65:1 rocker ratios on a 538/.533-inch lift cam on the stock 3.736 inch bore.

Doom86

Good catch that is right on.

This is how he made the valves with that lift work.



I think with better heads he could use less duration and have the same power with the benefits of lower overlap. From what I found on my own build even a 1.94 valve could use this as well to get the most out of it.

Jack 305

If you want a 305 with more torque keep the cam duration between 203 and 208 intake and exhaust, depending on the flow ratio,you want a 10 degree difference,dual pattern cams aid in increasing the low to mid torque over a single pattern cam and valve lift,if possible would need be in the range of .500. Short duration and high lift cams will always prevail in producing a engine with more torque,regardless of displacement. Keep the original intake and exhaust valve sizes and concentrate porting the head to give maximum velocity. Smaller port volumes and valves aid in maintaining peak torque in the lower RPM range of the 305 displacement. The 305 is a very small mouse and in my opinion needs to be built that way.

Air_Adam

Thats what GM did on the 396ci BBC engines too, when they used big valve heads.

Firebirda7x

I thought you could bore a 305 out to a 350, I knew it would not make a very strong cylinder wall though. But yea I don't think anyone says it's economical to go the 305 route, but it is possible to make good power out of one. I just don't know why most of the build ups I've seen have high RPM powerbands...