|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 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 12:10 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 11:34 AM|
|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.|
|02-12-2013 10:14 AM|
duration is the length of time that the valves are open
you need to have the valves open long enough to fill the cylinder.
think of filling a jar under a tap
when its full some flows back towards the top or splashes back
now put the lid on this jar,shake it and walk into another room,open the jar and pour out the water in another sink
how fast you fill the jar depends on the neck size or opening size(valve size in an engine)the water pressure from the tap and tap size (intake runner size)
lid on as soon as the jar is as full as possible without spilling
empty jar by turning upside down with lid off(think of a long neck pop bottle Vs a short neck pop bottle for exhaust)put lid back on as fast as possible so you can go back and refill at tap.
any wasted time and spillage is cam/head/carb/header inefficiency
|02-12-2013 10:11 AM|
|02-12-2013 09:22 AM|
|s-10again!||by the way, this is a camshaft that i installed in a marine 350. it only made 300 hp on a desktop dyno at 4700 rpms with the parts list i used and the guy at the marina who did the desktop dyno for me said i am an idiot. and i am. he proceeded to show me how some double springs and a different cam would have made 400 hp with my flattop shortblock (that i build with silvolites) with some different grind numbers. and it would do it at 4000 RPMS!!!!! i am an idiot and i want to get this 305 right on the money. shop that sold me the cam asked me about a parts list, i told him i had stock heads and thats the cam he gave me. he added no advise to this like the genius marine tech guy. the marine genius guy told me that the shop tech shoulda told me i was building a turd but i think he wanted to dust off this old cam and sell it. by the way the boat does haul some *** because it was origionally a 260 hp 350. i was able to prop up one size and ontop of that, i gained 1000 rpms above the old rpm and this thing sounds incredible at an idle, youd think i had a big block in that thing. did 46 mph, now it does 55 mph. id have the marine guy help me build up this 305 but he goes to florida in the winter and i am buying parts now. that is why i am asking so much on the forum lately. also whene i try to ask the marine guy to explain things he tells me to buy a book. hes probably right. he has been so far.|
|02-12-2013 09:10 AM|
Cam grind numbers
i have a REED CAMS serial number TM264. grind number is 330 TM264H-TM272H-110A3 it has a duration of IN.214 EX218 @ .050 . lift IN.450 EX.461. running duration IN 262 EX 272. spring pressure open 260-280 and 80-100 closed. lobe centers at 110 degrees at cam. exhaust centerline 116 intake centerline 104. what would this cam be good for and how do you understand what these numbers do for performance? the only thing i understand is that a cam is 720 degrees and the duration degrees are the amount of time subtracted from 720 degrees that the valves are open. I would assume spring pressures are stock spring configuration and the grind number at the end sais A3 meaning 3 degrees advance ground into the cam. what does all this mean for horsepower, how would i understand what this cam could do in different engine configurations? also would this be a good cam for a 305? im guessing that judging by all the things that have been said about lsa and .050 duration specs, this cam is not much for a 383...but much too much for a 305. im trying to get clue how to "understand" application. i have blueprinting skills and have limited machine shop background (not automotive but still mill and lathe and blueprint knowledge) so SOME of these numbers i understand but some i dont. If i understand this correctly, correct me if im wrong, the duration of the exhaust at 218 @.050 with the lift of .461 is max for stock springs because if the lift were more than this the springs wouldnt fully close even at respectable rpm within the camshaft rpm spec. and the same would hold true if you kept the lift number the same and shortened the duration? so whats better, lift or duration? If i were to get some great valve springs would a small duration number matched with high lift be good for a low rpm 305? also the lobe centers i have no clue how that affects any of this. advise, correct and teach me please?