31 replies to this topic

[MR77LX]

As some of you may know I have a 304 injected in my torrie.

The motor I have is currently out of a VR commodore and I also have a T5 manual transmission fitted.

Im up to the stage of putting a stroker kit and would love some advice if that�s ok.

I don�t know whether to go 355 or 383.

What sort of head work is needed on both stroker kits?

My torrie is not going to be made for the drags but I would like some nice horse power out of it.

I also do intend on putting a twin throttle body setup? Advice on what type would also be great.

Allot of people favour the 355 but why? The 383 has more cubes which obviously means more power.

Where is the best place to buy the stroker kits from?

Advice and opinions would be great!!

[rexy]

I have had both a 355 and a 383 holden built for me in the past and I would never do a 355 again. For the tiny amount of cost between them you would be insane to not go for the bigger donk. Lazy extra torque and HP for the same level of mods.
Plenty of the pros will be able to source bits for you eg crankshaft rebuilders, COME etc.
I think lots of people settle for a 355 because they deal with people with little experience who do not wish to display their ignorance and instead want to repeat what they already know.
You wouldnt spend big dollars on rebuilding a 253 when a few extra dollars gets you a 308 so why build a 355 when a similarly small price gap gets you a 383?
Dont be another sheep!
R

[MR77LX]

Thanks guys... If i decide on the 383, what type of head and cam work is required? And how much is it going to cost me?
What do u think of a twin throttle body set up also?
Scat stroker kit is what i will be using.

[MR77LX]

A 396 with standard heads, I wonder what type of horse power would that give compared to a 383.
Instead of twin throttle body, should i use that money instead for minor head work?

[rexy]

Iv done a 383 with minor head work and a pretty big cam cost over 11 grand made 380rwhp then fell flat at 5000 revs because of the stock manifold now is trying to sell it for 6 grand
Brothers got a 355 with mild cam but 4.1gears made 225rwhp droped out at 4 grand because of the manifold and low gears. Selling the hole car for 10 000 vs ss
For my torri iv got a 355 with a bit bigger cam then my brother it makes 300rwhp because iv got a C.O.M.E twin throttle body manifold on it.

so after seeing all them i would put it down to the manifolds

BTW C.O.M.E do kits with the stroker, (355,383,396) twin throttle body, and even with heads pretty cheap

So in other words the 383 made 80 more rear wheel hp than the 355 despite being all aver by 5000rpm???
Say no more, the answer is clear on what to build.

With all due respect 355EH there is a much bigger gap between the two engines than 15-25 hp. With the same level of mods on a warmish street engine its more like 60hp and more importantly 60 ftlb.

Baa!

R

[MR77LX]

That�s some great info guys! I appreciate all your feed backs.

The car is not going to be for the drags; however I do want some nice power at top end.
I will definately be running twin throttle body and bigger manifolds. However cost has a big part of it also. Do I need minor head work with the 355. If so roughly how much?
Head work is definitely needed with the 383, but how much roughly?
How much are the 355 come strokers, twin throttle body and even with heads worth?

[rexy]

Lads, perhaps we are talking about different ballparks.
Ken, yor previous posts suggest you have a decent brain. The mathematical modelling isnt nearly as simple as you imply.
Paul, you clearly have experience in this area but how often have you built the same engine twice with a change in capacity?
I have had this done.
The mildly ported stock valve iron VN heads ($800 worth of professional porting), redline hiwinder, 750 dp holley, Medium solid cam and pipes from my 355 were all reused when the 383 bottom end went together. Same 10.7:1 comp ratio.
The 355 made 405 hp and 410 ftlb
The 383 made 475 hp and 470 ftlb
These results were from the same dyno of a very reputable race engine builder. The driving experience in a LX was like chalk and cheese.

I appologise if my experiences seem out of keeping with others but they are what they are.

R

[rexy]

Clearly I have the have the hardest working 28ci in the world....
The comparison is what it is - direct.
All the above comments may have some validity to explain the difference.
A further couple of possible contributors: Piston dome configuration ( forged TRW in the 355, KB hypereutectic in the 383)
Rod length (short 400 chev rods in the 355, 5.7inch rods in the 383)
Johnno, both engines made peak torque at pretty similar rpm but the 383 had a much much fatter low end comparatively. We only dynoed them to 5500rpm as I am a bit of a nervous nellie. Power curves were still rising on both engines at 5500 but were starting to flatten off. There may or may not have been much extra. Certainly in car they were both done by 6300rpm.
Viper, the heads were done specifically for the 355. Reused on the 383 because they were already there and portmatched to the inlet manifold.

It is not nearly as simple when comparing combos as saying divide by cubic inch(old) and multiply by cubic inch(new).

A vigorous debate indeed! Good for the soul.

R

[MR77LX]

Ah i went a 383 stroker from come racing and I’m very impressed.
I must admit there is a bit of work that needs done to the block but overall i can’t complain.

I have done 1000Kms now in my 383 and I’m just about ready to see how much HP i can get out of it.

I have also fitted come racing aluminium heads, come twin throttle body set up and come ecu.

[MR77LX]

Its going good Jack.

Unfortunately i havnt spent much time on it due to a new garage that we have built.

But now im hoping to get back into it. Dyno is not too far off.

I need to fix an electrical issue that i cant figure out.

Its been to several different electicians and they cant fault it.

So once that is  fixed and sorted, then dyno is my next step.