Jim85IROC

iTrader: (2)

I apologize for being an East Coast guy posting in the Cali forum, but I was hoping to get the expertise from the "Cali" group of TPI guys, i.e. Kevin, Dyno Don, Jerrywho, etc. These guys are the only guys I know of that have real flow data supporting their TPI modifications.

So, on with my question.

I've seen the impressive modifications that Don & Jerry have done with the Edelbrock Vortec TPI base and the e-tec 200 heads, achieving flow rates of around 300cfm on the intake base and nearly that on the heads. My desires are more modest. I'm running unported, untouched SDPC Vortecs (modified for .525 lift, but completely stock otherwise), which I believe flow in the 235-240 cfm range @ .500 lift. My valve lift on the intake is at .471, so for the sake of conversation let's say that my intake will pose a restriction if it flows less than 240cfm. With that desired cfm, and the stock intake port size of the Vortec heads (vice Don's 200cc e-tec intake ports), what steps do you guys think are necessary to achieve that flow? I've got mildly ported SLP runners and a port-matched plenum.

My plan right now is to grind away most of the injector boss that's protruding into the port, and port the short side radiuses of the base in order to achieve a better "line of sight" between the runner and the head port, along with an overall smoothing of the walls.

So far I've ground down the injector bosses and done a little bit on the short side radiuses that I can reach from the head-side of the manifold. I haven't attacked the runner side, but I don't see that side as being as critical.

Before:


So far:





Based on the fact that the stock Vortec heads with my cam are really only going to be capable of 230 cfm, how much more work is really necessary to ensure that my base isn't the restriction here? How much should I straighten out that short side radius? I've got enough material to take at least another 1/8" or 3/16" away, but by doing that it widens the overall runner width considerably. Will that negatively impact velocity?

Guest

I'll Be the first to reply and give my two cents on the Vortec's They have the E tec 200's I have the standard Iron Vortec. I did have Don put in new manley springs an retainers. Jerry cut down the stud boss? not sure if it's called that but sounds good..I had Don Port the intake side an port an polish the exhaust sides. Now my Vortec's are on a 383ci so I needed all the flow I could but I let Don handle an make all the money. So Don mildedly ported the Vortec base also. I have a Honed Super Ram.
So I did not want to spend all this extra money to have the base honed because of the flow of the Iron Vortec. Now these Vortec's flow almost the same as the standard Afr not the race not the eliminator not the cnc, just the standard 195 Afr. So another thing is DynoDon's custom headers, your going to need a set of those for your Egr if your smog legal where you are. And even if your not the Vortec probably requires it anyway's but some one else needs to explain that. And in my honest opinion Don has the best. I mean the best 1 3/4 header out there and also could be made to be a Hi rise header, so the flow is correct.

I say get the Base Honed out. I say get the heads professionally ported and get them flowed. I say get Don's 1 3/4 header. And I say get rid of the Slp runners and get a Super Ram or a Mini Ram. So my advice is let a professional place hone the base and depends on the heads Leave that one to some one else more skilled with that head.

So this is a start they will explain to you what they really do..

I dyno Jet tuned dfi gen 6 on 110 octane wide band, fuel map 389rwhp an 442rwtq. 5,600 rpm And we could not even touch the timing yet. I could not afford any more Dyno pulls. Because I'm paying a driver I'm paying the Lamba wide band I'm paying a tuner and I'm paying the Dyno. And this was all done at Blower Drive Service.. Better Known as BDS.. My car had a engine bay fuse problem with the fuel pump or else we would have street tuned for the timing.. My ECU has been tuned just as good as the dfi and It ran faster 1/8th mile than the Dfi.. The dfi required old lap tops so I got out of it for that reason. And now the ecu equipment is just as good on the fly tuning or on the road direct change to the ecu like Dfi is.. Leaving the DFi no longer needed.

Oh Another note they have gained more horse power but I gained more torque
being my engine being a base torque combo it's not bad for an Iron Vortec an mild porting. The E tec will flow much better so if you do everything right there should be no reason not. Also find out there grinds on cams and compression there running.

Kevin91Z

iTrader: (1)

Jerrywho posted a thread in the TPI section a while back on what he did to get Dyno Don's Vortec TPI manifold to flow in the 280+cfm range. I think he said he spend a whole week on it. As in 40+ hours.

It sounds like you're on the right track in grinding those areas for your valve lift and head-flow potential.

Guest

Jim85IROC ignore everything from Kevin's post down. Just find the thread that Jerry did like Kevin mentioned..Good Luck with it..

Jim85IROC

iTrader: (2)

I'm very familiar with that thread. It's a wealth of knowledge. Unfortunately, it doesn't really shed a lot of light on what you need to do to accomplish more modest flow numbers like I'm after.

Orr89RocZ

iTrader: (20)

Port match the intake opening to the vortec heads opening and then carry that opening cross sectional area into the runner. You want minimum cross sectional area to be at the inlet to the cylinder head port on that manifold. So port match it, and work into the runner opening things up to match or slightly exceed that dimension. Helps to measure your ports width and height as you do this to know what the area is. You want alittle bit of taper from where the tube runners join to where the injectors at base opening to the head.

You need area to pass flow. You only have so much area to work with on vortec heads (small intake runner as it is), so the best you can do is port match the base and taper the port to the TPI runners.

THe big restriction is the bend of the runner. More flow loss there, so if you could port the runners, open them up as large as possible.

I think you are on the right track. Get those injector bosses out of there and that will greatly open up available cross sectional area to pass flow.

Jim85IROC

iTrader: (2)

The injector bosses are mostly gone. The runners I haven't looked at yet. I did some minor porting on them years ago when I first installed them, but it was minimal. Based on my measurements so far, the smallest area on the base is right at the head and injector boss area. The manifold right at the head has the exact same width as the head itself. I still need to check the height, though I'm unable to take away any more material there anyway unless I relocate the injector bosses.

Orr89RocZ

iTrader: (20)

Injectors can stick out into the port alittle bit...its sorta like a valve guide boss in the head port...the rounded profile will still pass air so it wont be too much of a restriction.

Jim85IROC

iTrader: (2)

I've already ground down to the point where I broke through into the o-ring seat. If I go down any more, there won't be anything to seal the runner from vacuum leaks. I can't remove any more of that injector boss without welding a new one in father out.

Orr89RocZ

iTrader: (20)

Ah, I see.. In that case you are good on height. Only other thing you could try to do, to the roof, is grind down the left and right sides of the injector boss area, along the walls of the port to gain more height. Then just in front of the boss where it goes into the head, leaving a wall on the boss for the oring seal. Taper it back into the runner to make the boss a tear drop shaped vane. Treat it like a valve guide, but I dont think this is gonna be necessary for your application. I think where you are at is about the limit you can go without raising injector port. It should flow enough for your goals

Nelz

How did your manifold work out? I was too scared to grind down the injector bung but smoothed out the bung a little like high flow fuel injection did here.



Was there enough material for the injector to seat and not leak?

1989GTATransAm

iTrader: (3)

Mainly you want the injector o-ring to be able to seal. So lube up and injector and stick it in the hole and as long as the o-ring is still sealing you are good to go.