|02-12-2013 03:24 PM|
|1Gary||And if your looking for a long term goal after that,given what your describing,a LSx is kind of a cake and eat it too.Gas mileage/and performance.But right now even after 14 yrs of production,to rod a LSx is expensive.Figure from $5,000 to $7,000 grand when it's all said and done.So to hold off on that right now to wait for the aftermarket to get more production/sales so the parts costs go down wouldn't be a bad thing.|
|02-12-2013 03:07 PM|
Find a donor truck in a crash sale or at a impound lot.Junk what you don't use at a steel salvage place and get some of the money back for the conversion to your S10.
The Vortec 5700 L31 is a V8 truck engine. Displacement is 5.7 L. It is the last production Generation I small-block from Chevrolet. The cylinder heads feature combustion chambers and intake ports very similar to those of the LT1 V8, but without the reverse-flow cooling. As such, the L31 head is compatible with all older small-blocks, and is a very popular upgrade. It offers the performance of more expensive heads, at a much lower cost. It does, however, require a specific intake manifold (a Vortec head has 8 bolts attaching the intake manifold as opposed to the traditional twelve bolts per head). The L31 was replaced by the 5.3 L 5300 LM7. The 2002 model year was the final year for the L31 5.7 L small block V-8 whose origins date back to 1955. The Vortec 5700 produces 255 hp (190 kW) to 350 hp (261 kW) at 4600 rpm and 330 lb·ft (447 N·m) to 350 lb·ft (475 N·m) of torque at 2800 rpm. It is currently being produced as a crate engine for marine applications and automotive hobbyists as the "ramjet 350" with minor modifications.
|02-12-2013 02:47 PM|
Here is a example of a 372 HP 305.
Note that it does not even start getting busy till 3000+rpm
I get this kind of head flow from my fully ported 416's but you got to get serious with the grinder.
Here is a 343hp 305 with 416 heads but they *****ed out on them with the porting.
They did not open them up enough. Thus the lower peak HP
Look at the torque curve.
needs a serious gear and converter stall and rpm.
You need to buzz it up to as close to 7000rpm on the shift as possible.
Thats why a small street solid flat tappet cam is better.
Reference: Comp cams XS solids 12-675-4 12-676-4 12-677-4
|02-12-2013 02:12 PM|
If you want torque (what you really mean is acceleration) out of a 305 you got to rev it up and gear
the crap out of it. Same as a 283 or 302 or 327.
Hot rodding a small motor increases the hi rpm torque. You gear the car way up and rev it up to make use of it.
now you got seat of the pants "torque" ---acceleration--
when it gets to 6500rpm shift it. The more gear, the better it will do that.
You are not going to save gas by hot rodding a motor.
If you want to save gas use a stock fuel efficient motor and drive it like its the last
engine on earth.
|02-12-2013 01:46 PM|
If you are going to try and do something with the 434 heads you are really going to have to get MEAN with a die grinder on them. More is better. It will take serious porting. Get in there and lean on that grinder.
The 434 heads have the same crappy exhaust port roof shape as the 882's around the guide.
It will take serious carving around the ex guide to create flow paths.
You can make any stock head better than OEM but these are not the good 305HO heads. (good: being a relative term)
The 434 chamber is around 64cc +/-. Thats why I don't use them. Wrong chamber and ports as a start point.
Just don't lower the floor of the ports. (it's bad enough already)
Getting the finished cr right is critical. More is better. up to about 10.5:1.
Flow and cr.
|02-12-2013 12:57 PM|
|s-10again!||i guess i kinda bit off a little more than i can chew here, soo many great ideas that will work for me. you all can get the job done here and all have a different approach to get there. basically i have to take this discusion and think about which approach to take. its either boneyard 305, build up the perfect 305 roller, or use all the junk i got laying around and do the best i can with it which is still going to cost some money.|
|02-12-2013 12:27 PM|
305 Vs 350,which is better
either engine will work. look around for a deal.If you want dirt cheap,dont care how long it lasts,moderate power,
buy a complete running car from a wreck. take out engine,(pick a car that has a roller motor)regasket/clean/replace timing chain,buy a cheap cam,use FBs back yard porting method,drive a car that performs as it is built.
|02-12-2013 12:16 PM|
|s-10again!||not a damn clue....ooo look somethin shiney!!! im under the impression there the same parts and can be swapped to a larger 350 later on. need more rpm for 350 parts in a 305 to work right.|
|02-12-2013 12:11 PM|
In other words you don't know how to hot rod a 305.
|02-12-2013 12:10 PM|
|02-12-2013 12:06 PM|
|JeffB||With the cost of aftermarket heads available you are wasting your time and money fooling with a stock head.The budget you have to work with will take some smart shopping for parts,the cam you have would produce some good low end and mid-range power but you should go for a 350 build as those parts are more budget friendly.|
|02-12-2013 11:49 AM|
If you want fuel mileage get a Honda.. If you want fun Supercharge a 305.
You can buy a whole rusted out car with a 305 in it for $100. or less.
If you want gas mileage from a L-30 305 vortec motor install it stock.
Get all the stock stuff from the donor truck. Trans, computer, fuel system, exhaust cats
everything. Install the WHOLE system in your S-10 in stock form and don;t touch it.
Shut the hood and drive it.
But of you want fun, Supercharge a 305.
|02-12-2013 11:34 AM|
|02-12-2013 11:22 AM|
the 434 heads stink. You cannot get high horsepower from a small motor at low rpm.
If you want tlow rpm get a diesel or a 454.
live a little rev it up. you want to agressively port the head. but not polish . and don;t bother starting with a #434 head.
Find a 4416 or a 601 or a vortec head. Or a 081 or 083 head. The 450 and 434 low perf 305 heads suck.
start with the HO heads and port the crap out of them.
You need flow to make HP. and RPM.
When you port a stock head for power you need to make serious dent in it.
YOU NEED FLOW. You will not get flow by *****ing around with a dremmel and sanding rolls.
This is not a low rpm motor,,, cam, especially in a 305.
when you cam up a motor you need to rev it up.
when you hot rod a 305 you need to rev it up. In a 305, this cam does not get real busy till 3000 rpm.
it wants to rev.
Hot Rodded small motors want to rev ...
You cannot increase the low rpm torque output by adding cam to it. especially on a 305.
Find some 4.10's
|02-12-2013 11:15 AM|
|s-10again!||whene you say modified...if i were to grind the ports myself...could that help? as i understand it now, it is bad if i smooth out the intake runners and ports, i will loose precious atomization at low rpm? is it even necessary to port the heads if theyll never see any high rpms? how much "flow" do i really need at a low rpm? how do i know what flow number ill need to get intake velocity? there is so much experience needed to hop up a stock motor. i would just pick a old standby build and go to town if if i wanted raw power. speaking more of the heads, i dont even know what the intake runner cc's are, nor the exhaust. they are 1.84 434 castings. i guess at this point the heads are the real factor. parts matching is something for veteran builders i guess. i kinda understand it but once you figure out one aspect there is another limiting factor that kills any medium i thought there might have been. thank you very very much for your patience and insight.|
|This thread has more than 15 replies. Click here to review the whole thread.|