1MeanZ

iTrader: (9)

hey guys i have a set of stock 305 heads and 1.94 intake valves and valve springs from a stock LT1. my options are port the stockers i have lying here and install the big valves, buy some 113 casting vette heads, or the SR Torquers. i have read all the posts of people debating this but no one has any power numbers to back anyting up. i would rather port my stock 305 heads but will they flow as well as the vette heads? i thought there were some ported 305 flow numbers somewhere but i couldnt find them right off hand, maybe i am blind. anyhow, i am lookin for guys that can back up their ideas with power numbers. i am gunnin for 13s and dont have much cash to spend, so let it fly guys!

N8MAN1068

i'll have some numbers this summer.
85 305
113 heads
comp nx262 cam
lt1 intake
hooker 2460's
going through as yet to be determined stall (24-2800), th350

just gotta find the time to put it all together, tune it, and let it roll.

Captain C

One thing to consider is the combustion chamber shape. The 350 heads have a larger diameter chamber which will make for a horrible quench. They flow 185 cfm stock on the intake side.

The 305 S/R's with 1.94's will flow 207 cfm IIRC, I think they flow 227 cfm with the 2.02 valves on the 350 heads. I have the flow numbers at home.

I don't have a clue what the stock heads willflow with the full port job. I looked at it on a link from this site a few weeks ago so you can find it if you will do a little looking.

Better check on the length of the valves from the LT1 heads. I think they are the same length as the Gen 1. The LT4's are longer than Gen 1 valves.....

Bottom Line: How much are the 113's going to cost you? And a poor choice for the small bore 305 to boot. How much is the port job on the 305 heads going to cost you? You will have to pay to have the seats cut out for the larger valves. You will also have some major work in the bowl area to blend everything to the new throat size. Then there is the valve job itself, which you want to do after you do the bowl work..... If you pay someone to do that you are talking around $500.... Not to mention new valve springs, and working over the rest of the port...... You could almost end up with as much money as the S/R heads for a product that isn't as good. As I have mentioned in other posts, I am not enamoured with the S/R heads. Just they are the only thing that will work correctly with the small bore..... Too bad someone doesn't make a really good head for the 305.....

1MeanZ

iTrader: (9)

yah i will need the valves cut in, then i was gonna use a standard abrasives kit to port them myself, then they will need cleaned, surfaced, and a final valve job done, i dont know for sure how much that will cost, at that rate maybe it would be best to go for the SR heads

N8MAN1068

113's can be had for >$500. I paid $100 for mine, complete with covers, valves, and springs already installed.

113's are an excellent choice for 305's. they have the same 58cc chamber, and are a direct bolt on. Iron L98 heads, are a different story. 113 heads are also 'zz4' heads

Port job will run $40 in supplies + whatever dremmel you go with...this is, if you do it yourself.

305's can be made to go fast.
there are several in the 12's, a couple in the 11's, and 1 that i know of in the 9's.

I have some flow #'s from a ported 113 head somewhere...i'll see if i can find them.

Captain C

My only concern with the 113's is that the "diameter" of the chamber is designed for a 4" bore. The small chamber volume is great, but the chamber will extend outside the bore on a 305. this will create a poor quench area. Other than that they are perfect for a mild 305......

The chamber quench design on the World Products S/R and S/R Torquers is very 1960's for the 4" bore street heads. Their Sportsman heads have a much better chamber. I haven't looked at the chamber of the 305 head but I imagine that it's similar to the torquer, just smaller....

Fast305

Very few changes made to my casting number 14022601 heads. Removed casting flash, gasket matched heads, intake, & exhaust manifolds. Put in a larger cam. I am running precision engine parts 1.84 & 1.50 race valves (stainless, undercut, swirl polished). I also have Z/28 springs, chromemoly retainers and keepers, and new seals. The guides were replaced with bronze guides. The valves were installed with a good 3 angle valve job. The heads were also angle milled dropping the chamber from 58cc to 54 cc. The heads also end up being like 20* heads instead of 23*. Half way to 18* heads!!! They are on my G20 Chevy vans little 305. It is a potent little sucker. The total cost was around $600.00 for everything I have done. That includes cam kit, gasket set, valvetrain components, rebuilt heads, and misc other things.
Here are the flow numbers @ 28 in/H20.


Lift Intake Exhaust
.050 35.60 15.00
.100 72.40 47.00
.150 105.8 72.50
.200 133.4 98.00
.250 154.1 117.5
.300 180.6 137.0
.350 195.5 145.0
.400 209.3 153.0
.450 217.4 155.0
.500 224.3 157.0


Here are the DD2000 predictions on horsepower.

RPM HP TQ
2000 113 297
2500 146 308
3000 185 324
3500 218 327
4000 246 322
4500 269 314
5000 282 296
5500 279 266

The actual dyno numbers through the power robbing van accessories are in my sig.

Guest

Willie's car doesnt seem to mind too much.

1MeanZ

iTrader: (9)

wow fast305 i almost believe those numbers you put up there. looks like you forgot to read the subject of my initial post NO BS. so stop spreading it around here. i want to know how you got a 305 casting with a 1.84 intake valve to outflow an LT1 head and flow about as well as a vortec head.

by the way nice van???

ray royer

just curious what tim burgesses heads flow. he has 1.84 valves in his 305 iron heads. his 305 runs twelves all motor and elevens with nos. so you can have good flow numbers with 1.84 valves.

1MeanZ

iTrader: (9)

yah i know they can flow decent but from a stock cfm of about 177 to a cfm of 224 @.500?? that seems like a bit much to me.

Fast305

NO BS about this post. I don't know if canadian heads are different than american heads but mine are medium duty truck heads that came on my 305 originally. Actually mine were close to 200 cfm stock @ .500" of lift. Don't go crazy with the opening up of the ports. That kills velocity therefore flow at low lifts and engine speeds. Clean up the casting flash and match the ports to the gasket. Clean up the bowls a little but try not to change the shape much. 1.84 valves will actually be unshrouded when compared to 1.94 valves in the same head. Just look at how tight 1.84 valves are on these heads. I unshrouded the intake valve some on my heads. On a 305s small bore 1.94 valves actually hurt flow. Also compared to cylinder volume the 305s 1.84" valves are similar to a 350 with 2.02 valves. Meaning the 305 has plenty of flow for its displacement with 1.84 valves. The valves I used were worth 18-20 cfm on the intake and 10-15 on the exhaust. This was on stock ports too. Oh yeah I really ground the exhaust ports. They are mirror finished in an attempt to keep carbon from building up in them.

smithtc

iTrader: (5)

It's amazing what 5 minutes of doing a "Search" will do for ya...



https://www.thirdgen.org/techbb2/sea...der=descending


You can do a search for F-bird'88. He ported his 416 heads, and has posted his qtr times somwhere I believe.

I won't do all the work for ya.

Have a nice day

SuperSwapper

I have a set of corvette aluminum L98 heads that will end all of your problems, they have been milled down to 56cc... they have a competition 5 angle valve job with new stainless valves, (1.94int,1.55exh) and they have been PROFESSIONALLY ported and polished, not dremel tooled in some one's basement. They also come with new .550 lift hi-performance valve springs. im asking $900 for them, i also emailed you.... twice.