SVTlightning87

i hear that a 383 stroker is a inefficient motor? i dont know what this mean and if its true, opinions?

Ace$nyper

iTrader: (8)

How so, or was that all you were told?

Now with the low cost of 6Ls and the LQs alot of people feel the bang for buck on LSX 383s is lost. Unlike an old SBC where 383s are kicking cheap and simple.

67Ranger

iTrader: (16)

I dont see why it would be inefficient. What were they saying would make it inefficient, and inefficient in what way?

SVTlightning87

thats just what they said, im looking at a new Short block and im wondering how much more in the long run it would be to do a 383 or 402

Beast96Z

iTrader: (21)

Roughly the price of the LS2 block, but if you were going to by a shortblock already complete, like most do, It should be roughly $500 or less diffrence.

Benjamin Russick

iTrader: (1)

If by "inefficent" you mean "not cost-effective", I would tend to agree. I have a 383 and it is great, but with the marginal cost difference in going up to the larger bore, it is outdated. You have much better heads availible for the bigger bore engines and with the proliferation of the 6.0 the prices are dropping. I bought mine because the price was right and I was pressed for time. If I was to do it over, I'd go aluminum 402+...

beardWS6

iTrader: (1)

Iron 408 all the way. then spray the **** out of it!!

slow trap

iTrader: (22)

i see in the dyno section quite a few 383s that barely out hp a 346 so that may be where they are coming from but the added stroke gains quite a bit of tq and you don't have to spin them to the moon like a 475 hp 346 6700 rpm + to get decent power.just my $.02 though.

badpewter-z

iTrader: (4)

its only inefficent if its not a good combo like anything else
it will make more hp than a 346 but not a huge amount just sooner and carry it better , now tq is another story you will gain alot of tq and again come sin sooner and carrys across the bored. ill have my 346-383 numbers next week but just from driving it there's a HUGE tq difference.

like stated above though unless you get a killer deal on a 383 a 402 isnt all that much more and net you even more power an tq .

erikthegoalie

iTrader: (29)

This day and age, I'd go LSX block and bore it out larger than any of the metioned above...it really is the best "bang" for buck

tee-boy

iTrader: (8)

An engine's efficiency is a function of it's compression ratio. Higher compression equals higher efficiency (it puts a higher percentage of heat produced in the chamber into work against the piston). Diesels are the most efficient engines. If you assume 1 lb torque per cubic inch, you get an additional 37 lbs of torque on a 383 vs 346 (that translates to 37 hp at 5250 rpm).

Sigforty

Compression helps, but it is also about the entire package. Right now my 383 is not very efficient due to having a small set of heads on it (Dart 205s). I am planning an upgrade over the next 3 months so I will see what new heads do. The 383 though does have and entire 50 ft-lb of torque gain over my previous H/C 346 combo. It also makes decent rwhp at 487 with the small heads on it. I feel with my new set of heads my 383 will go up to around 510 rwhp 500 rwtq or better.

Bo White

iTrader: (59)

Some engine builders will say that the 383 LS1 engine is not effecient just for the fact that its an oversquare engine meaning more stroke than bore(4.00 stroke, 3.905 bore). I say that its not that simple, IMO the longer the stroke the longer the connecting rods need to be to keep a good stroke to rod ratio. If you take the stock LS1 with its 3.622 stroke and 6.098 rod its got a R/S ratio of 1.68 now take the same engine and stroke it to 4.00 and then youve lost alot going to 1.52. The more ratio you have the less angle you have on the crank at mid stroke for more direct/straightline path of leverage to turn it. So this is why I like building LS1 strokers with 6.200 rods since they have a R/S ratio of 1.55, which IMO is the minimum ratio to run in a performance engine. Now on the bore, the bigger the bore the less shrouded the valves will be so they can breath...as long as the cylinder head has been worked to take advantage of a large bore.