I hope that this hasnt been posted yet, it's been a while since i've posted.

If anyone else reads Engine Masters magazine, you've surley read the article about the 305 build in the latest issue called, "Hate me". They used the following parts:

LG4 ( i think, they talk about an LB9, but the pic of the block says "LG") with dished pistons
Holley 650 4bbl
COMP XE268H 224/230
RPM AirGap manifold
EngineQuest Lightning vortec heads 1.94/1.50 with roller rockers
Headers (i dont recall what they used)

Not bad at all. Those heads are hella cheap! They say that the 305 is shunned becauseof the bore size, but they said the stroke/bore ratio is slighlty better than a stock 454 (did not specify BB or SB).

Take that! I'm stoked because I used very similar parts and did much more than them.

The motor did 372 @ 6100 on the engine dyno.

 

I think I'll have to go find that magazine and have a look at that article. After I get done repainting my 87 Z28 and having the interior replaced, I'm going to look into the motor department.

 

All the blocks say that, has nothing to do with it being a LB9 or LG4.

Based on previous builds posted up by them I seriously doubt its a run of the mill build.

 

L stands for Liter and G stands for Gasoline on the sbc's.
5.0LG and 5.7LG

 

It was, read the article. Go to wal-mart and read it in the isle, it's not that long. They pulled the motor off of the rack where it was stored in the back of a shop for some time. It WAS a run of the mill block, even had the good ol iron manifold and q-jet that adds 1000lbs to the car's weight. They dyno'ed it stock and it made 213hp, then they put in the cam, heads, manifold and carb and then dyno'ed it again after the break in.

Either way, it wasnt much money and it is cool that they were able to get 372hp from it without much work.

Learn somethign new everyday.

 

That is no suprise to me. My 312 (.040" over 305) has made 423 FWHP @ 6,300 rpm on the engine dyno. Still breathing through TBI as well.

 

Thats a pretty big cam for a 305 as a daily driver or are you talking about a 335 stroker? That would tame it a little but It would lope pretty dam hard and get low vaccum.

 

and just think a 350 would have made 50 more hp for the same cash outlay.

 

Exactly. Using the same hp/ci ratio the 350 would have made 427hp for the same money. Again this was on a dyno with no accessories and I would be interested in what the complete exhaust system was.

 

hey i have went to the engine master website and i cant find that article is there a way i could see it online?

 

I suppose if one had that engine he could just tell everyone it was a 350 so that they would stop telling him to swap out to a 350.
But then it would lose the "wow" factor of it being a 305 I guess. I for one think that is an awesome build up, I'd like to try something along those lines someday.

 

I see that combo as being a solid 370HP build, on a 350. I honestly don't think those parts there would make 425HP on a 350, which leads me to believe it'd be "tricky" to make it happen with a 305.
I do believe the 350 would generally make 50+ HP, but 425HP sounds high for that combo of parts.

 

I agree. I think the bore/stroke card is WAY overplayed when people are trying to "diss" the 305. It has a bore/stroke ratio of 1.10, which is MUCH better than another highly respected and sought after small block Chevy engine; the 505 hp LS7, at 1.03 ratio. How come it's valves aren't "too shrouded" to do anything with? I think the 305 has about as much potential as any other ~300 CID engine.


And a 400 would make another 50. So?

 

my buddies 91 caprice 350 shortblock with vortec heads, rpm manifold, 750 carb and stock LT1 cam made near 350hp. his 83 shortbed chevy ran mid 13's at 98-99mph so it has to be near 350hp at that weight. my car probly makes near 280 on motor and i run the same times he does.

that cam is tons bigger than stock LT1. i could see 400crank hp easily on a tune

 

The bore/stroke ratio has absolutely nothing to do with the valves being shrouded or not. It's about how much room you have for the air to move between the valves and the cylinder wall. The 3.736 bore gives you less than .100" on either side of a 2.00/1.55 valve combo (3.55" across valve to valve) - due to placement in regard to the center of the bore. The LS7 LS engine has a bore of 4.125" with the 2.02/1.60 valves (3.62" acrosss valve to valve) and closer to .25" clearance on each side. That's a big difference as you can see head flow jump 20cfm or so going from a 4" to 4.125" on the flow bench.

You can get a 305 running quite well with Vortecs and a good cam and would surprise many 350s,, but their really is no replacement for displacement,,, especially when increasing the bore is concerned.

 

hmm, based on the numbers, mine is making nearly 440fwhp...

 

The LS7 certainly does have more room valve-> cylinder wall; it's a bigger engine. Every dimension is bigger! But it also has a much larger volume (bore and stroke) to fill than a 305 does. The ratio still works the same way, whether you're talking about a lawn mower engine or a battle ship engine, and it's worse for the LS7 than it is for the 305. Yet the LS7 seems to do O.K. by most measures. My point was that the bore/stroke ratio on the 305 isn't as detrimental to that engines potential as people make it seem.
You're right though; there is no replacement for displacement -that's certainly a no brainer.

 

Bore/stroke ratio aside, what happens when you increase volume is that the surface area doesn't increase accordingly. Breathing takes place via that a percentage of that surface. So I conclude that a small cylinder has the potential to breathe better than a big. It's not without reason that you tend to increase the number of cylinders as you increase engine size.
And how about those small 3.5cc model car engines that churn out 2.2 hp? Granted they are 2-stroke, run on 35% nitro and turn 32000 rpm, but what would it take to make a n.a. 350 churn out 3583 hp? I'm just asking..
Don't get me wrong, I accept that the 350 is cheap and easy bang for the bucks, and I love big engines with loads of torque, but this thread was about horsepower in "small" engines.. Or?

 

There's nothing "wrong" with the bore to stroke ratio in the 305 or even the 334 (305 w/400 crank) for that matter. The 305 or 334 can make power and they respond as well to modifications as any other SBC up until a certain level. Here's a link to a post I made some time back with a 325hp Vortec 305 build and a 387HP @ 6000 rpm 305 build. I included a run of the mill 350 Vortec build and graphs to show the power difference between a similarly built 305 and 350. The 350 with a point less compression and 6degrees more duration at .050 with fractionally more lift produced 100,, yes,,, 100lb/ft more torque at 3000rpm and 86lb/ft peak to peak.

I'm not knocking the 305,, you can get them to run,,, I used the old L69 as a back-up engine when I pulled the 406 out of the Monte for a fresh-up and upgrades many moons ago. I pocket ported the heads, lapped the valves, threw in a 225/225 - 108 Lunati I had laying around,, used the oversized 7525 Team G single plane I was running on the 406,,, the same tricked out 750 vac carb I had on the 406 as well as the 1.75" headers and dual 3" exhaust. I about crapped myself when it ran a 11.87 on a 200 shot. That was a cheap solid 11-second ride and I got more complements on the way it sounded (it hit pretty hard) compared to the 406 that idled relatively smooth,, but was 1/2 quicker off the bottle than the 305 was with a 200 shot.

Anyway,, just passing on info.

https://www.thirdgen.org/forums/tech...ortec-afr.html

 

http://www.popularhotrodding.com/eng...cks/index.html

there is the link to the article online. enjoy.