iansane

Takes a confident guy to admit something like that.

I didn't get a chance to read it, lots of surfing and reading about turbos to do. What are the differences between 305/350 vortec heads? So they used 350 ones and got the best results? Were they milled down any to increase compression or what cc were they? I guess I should just read and find out. hehe BTW, I don't think any reasonable person discounts that any engine including a 305 can make decent power, it's just the effeciency (=cheap to make fast) that it does so. Plus there is a huge stereotype against them.

I don't know much about engine building, just from what I've read so I'm not the person to take advice from. But the comparing the 305/307 to a 302 is like comparing the camaro ss to the cobalt ss. They're two completely different animals. They have totally different rod/stroke ratios. The 302/327 lend themselves quite a bit better to high reving (from what I understand) because of their larger bore and shorter stroke. Nothing to shroud the valves at high r's.

dahaus

You are right about the lack of comparison in the 327,302,305,307. They are all different. This is why GM made them. They are for different applications. The 305 and the307 were designed during the 70s and 80s, when they were in search better emissions and economy. The 302 was designed in the late 60s to be able to compete in the trans am series with the camaro. And, the 327 was put together for a bad *** motor. I don't know the exact reason why.

But, the question here is not what motor is better than the other. The question was, what can be done to the 305 for better power, and would it be worth it? My answer is use what you've got. That is if you are working on a budget. I have seen many 300 to 350 horse 305s with minimal parts and money.

If you have the money and the capability, I say get a LS1. The LS series of powerplants has to be the most impressive that GM has ever put out on the market. In my opinion.

iansane

Right, I was just stating the Laguna's comparison wasn't very accurate. Which you agree with.

Then the question comes into play. Which is more cost effective. Modding your 305 (eventually rebuilding it..?) Or just driving the 305 till it blows and save for a 350 build or building a 350 yourself. It's all in your end goals. If you never want to make large amounts of power then just stick with a 305 a mods. If you want to surpass 350-400hp easily (<--keyword right there) then save for a larger cube motor with more room in each cylinder for better air flow and a better rod/stroke ratio.

Lynk

It was the RS camaro that came with a 302 in 67 and 68. The 302 used the 4" bore block of the 327 (same as a 350) and the crank from the 283, the reason was becuase chevrolet wanted to win a series of rally races with a maximum displacment limit of 305ci (and they did!) and felt that the 283 was too small (Ford was running their 289ci). Anyway 305's are junk motors with junk cranks and junk heads. The 283 has one of the best ever made cranks, those motors will run 7500 rpm all day stock without hurting them in the least. The 4" bore block will go down in history as one of the best blocks ever made, please don't compare crap with crystal, the 302 is a legend the 305 is somthing chevy fans prefer not to talk about. If you put horse power to a 305 you will twist the crank. Yeah you can build them but why put more money into a motor to get less hp than you would with a 350 and then limit your hp with crappy heads and eventually blow it up after hitting 6500 rpm a few times.

dahaus

The 305 and the 350 cranks are the same!!!! They are just balanced differently for the difference in weight of the piston!!!!!

89385formula

Finally, this is what I said in another thread after the other guy repeatedly states that the 305 cranks are junk and twist. They are made from the same material, same process being made, and pretty much the same. Now I am not a 305 lover by any means, and you can certainly tell that by my other posts..but 305 had junk heads huh? What are you comparing these 305 heads too..AFR, TFS, Dart...? There are a couple stock 305 castings that flow pretty well really, and to say that the 350 heads and 327, 302 heads are better..I would wan't to know how they are being compared. Sure none of the stock 305 heads flowed as good as an aftermarket head. The Al L98 heads can't touch an LT1 casting, the LT1 casting can't touch a LS1 casting...what is your point? There are a couple 305 castings that flow pretty decent for what they are and would probably outflow alot of the 350 heads. 283's run 7500 all day long, thats super...its a commonly known thing that big bore small stroke cranks rev higher. I have seen plenty of stock cranks rev over 7000 and never have any issues.

Nobody denies that the stroked 305, or a stock stroke 305 will make less power than a 350. Thats his own choice. You don't need some crazy heads to support 400HP sorry, The heads that came on the LB9's with some work should be up to task for that really...and if he wanted more I am sure the TFS heads for the 305 would be super, or even the AL L98 heads would be sweet for it. The stock crank will be fine to over 400hp with a good balance, decent rods( factory or some cheap I beams), and a good forged lightweight piston. The excess weight than can be shaved off with a Eagle I beam, and a light piston will relieve alot of stress on that crank. With the right parts the 305 can make 400hp, can a 350 make more...yes. Can a 305 be made fast...well fast is a relative term I suppose....it may be fast to you, and not fast to someone else. To each his own, but Lynk stop being a hater.

dahaus

I just looked at the specs on those TFS 305 heads. I can't wait to see some tests on them. I they are as good as I expect, then this would definately be the way to go with small bore motors. This solves all the issues with valve shrouding. I think I'm gonna start saving money.

dahaus

they are listing the tfs heads at about $900 and the world product torquer heads go for about $650

85_305

^So do you think that the TFS 305 heads would be better than vortec 350 heads for a 305? And what about the world product torquer heads compared to the Vortech 350's and TFS 305's?

dahaus

I think that both the torquers and the tfs heads should be better than the vortec 350 heads. These aftermarket heads have a combustion chamber that is designed for the 305 bore. But, the link earlier in this thread showed us an extra 20 horsepower with the vortecs over the torquers. So, I'm not sure. I guess the only test would be a comparison of all three heads on a 305. Flow numbers wouldn't be a good comparison, because the vortec heads were tested on a 4 inch bore.

85_305

Hmm.. you have a good point. Why do you think that the Vortech 350's give a 20hp advantage over the heads *designed* to be used on a 305?

dahaus

I'm not sure other than the vortec head has a small chamber and maybe it doesn't interfere with the 305 bore. I have a 305 block and some vortec heads here. I think I am going to look at how they line up sometime soon.

85_305

Well make sure you come back on here and tell us what happens

engineermike

I thought is was only the early Z/28 Camaro's that had the 302's. . .

Anyway, there was a dyno test over 10 years ago that tested stock versus 305 Torquer versus TFS Twisted Wedge heads. The TFS's made the most power despite 2.02/1.60 "shrouded" valves. Hell, the intake valve almost touches the cylinder wall.

I had an '89 Firebird Coupe with TFS Twisted Wedge heads, ZZ3 cam (208/221), Edelbrock Performer TBI intake, Edelbrock headers, etc. . . that ran 14.20 at 97 mph. Not too bad, but a short block swap over to a 350 (no other changes - same cam, heads, etc. . .) netted some 13.30's at 106 mph.

Also, the Stock Eliminator 305 TPI and carb'd Camaro's that run stock heads, intake, quadrajet/TPI, bore, stroke, compression, etc. . . are running high 11's NA. But. . . Stock Eliminator LT1 cars are running in the 10.40 range.