Street Lethal

iTrader: (16)

There is nothing wrong with the 305 engine, other than maybe its' cast parts, which even the infamous Buick 3.8 turbo's were subjected to from the factory. To make power out of a small displacement engine you need to spin them higher, so remove any thoughts of building it like a 350+ out of your head way ahead of time. You want my advice, get stronger main caps, invest in a high winding cam, and get much stronger springs, and spin the 305 where it needs to be to make the power that your looking for. The 2JZ Supra engines share a similar bore/stroke combination as the 305 Chevy, but what drastically sets it apart from it are the cylinder heads, as it makes its' power up top. Port a set of 1.94" heads (unshroud them), open up your intake manifold substantially, get a bigger throttle body, high winding cam, tune it appropriately, and you'll make very good power from that little engine...

I decided to dyno the engine without the turbo in the coming weeks, so we shall see if all the work paid off for the anemic engine...

1991sleeper

iTrader: (-3)

Sweetness!! Yea post ur #'s man .. So far I think I'm just going to get it balanced , I'm using arp rod bolts and main studs , .030 over w/ flattop pistons , the intake (summit stage 1 ported ) and cam are good to around 6000 rpm .. Planning on shifting around 6000-6300.. Stock swirl port heads cut for 1.94 valves milled .010 , chambers cleaned up & polished , fully ported , 620CFM TBI , ebl flash , 1.6 roller rockers , msd billet distributor , true double roller billet timing set , shorty headers into 2.5" Y & full 3" uncapped at rear axle , 4.10 gears w/ T5 Trans , all tubular suspension parts ,

cam specs as follows - .488/.495 264/270 LC-114 ICL-110

Gross lift .325/.330 dur@.050 214/218

IO@-3
IC@37
EO@47
EC@-9
TDC overlap : - 12

I'm seriously thinking about sending this cam back and getting one with similar specs but with a 110-112 lobe center but idk yet

Street Lethal

iTrader: (16)

Worked 305 engine is now running, and the dyno will be visited shortly. This is a huge camshaft I am running in the TPI-305, and it idles like a purring kitten.

https://www.thirdgen.org/forums/powe...d-305-a-3.html

robertfrank

iTrader: (27)

So I thought I'd bring this one back from the dead as ivery been playing with another swirl port head just for giggles.
So...how far can you go with a Swirl Port head? Pretty damn far lol. I pulled the heads from my 4.3 and just for giggles I thought I'd play with one of the ports to see how much I could removed and as it turns out, you can go VERY deep into the heads if you wanted to. Now before anyone says "Dude what the ****??" I'm only doing one port just to see what could be done. Now, with out further a do. A ported out swirl port lol

Fast355

iTrader: (2)

To think back in the day everyone thought I could not be making the power I was with a lowly set of ported swirl ports and a F-car LT1 cam. I will admit though a set of light worked 906 canadian Vortecs with a 2.05" intake valve flowed over 250 cfm and the exhaust right at 200 cfm after port work and a 1.6" valve.

Now days you can buy knock off Vortec Aluminum heads with 200-210cc intake ports that flow that throught 2.02/1.60s for what I spent in valves, valvetrain parts and machine work. Run a higher DCR and full timing and make even more power from a lighter engine.

Street Lethal

iTrader: (16)

I forgot all about this thread, just seen I had a notification for it in my email lol. The last set of factory heads I worked on were the 416 heads, I'm currently running them on my turbo 305 engine. The heads were essentially ported to the max, I put a lot of work into them, but I won't have any dyno numbers for awhile, let alone any flow numbers for the heads themselves. Stock valve size though, but that doesn't matter as plenum volume is more important. With a turbo though, it changes everything, of course...

robertfrank

iTrader: (27)

Thought I'd come back and revisit this thread. My porting skills have dramatically improved over the last few years. I'm porting a set of 187's for a 334/TPI/ramjet cam build. I'll be opening the intake valves to 1.94. I just started on these.

robertfrank

iTrader: (27)

more

robertfrank

iTrader: (27)

robertfrank

iTrader: (27)

robertfrank

iTrader: (27)

I may open up the pinch a touch wider but I have to careful there as it is SUPER thin in that area

robertfrank

iTrader: (27)

robertfrank

iTrader: (27)

So I decided to open up the pinch a touch more and blend it up. It's as wide as I can go without busting through.

88RS

iTrader: (7)

Those look really good, Robert!

mmak116

Did anyone ever flow these ported swirlies? Just curious what the numbers are so I could decide if I should ditch mine in favor of something else for my new build.