TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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Ok guys, sorry it took so long, but as some of you know I ended up moving to central illinois and most of my crap is still in storage.
Also forgot my password for here so had to open a new account, sigh.
Finally found the flow sheets for the heads and some of my notes, so I'll post what i've got. And yes I found the pictures, but I dunno if waiting so long to get them developed, or if I just suck as a photographer, but they didn't come out worth a sh*t.
Ok as stated before all flow numbers are off the shop Superflow flowbench and corrected for standard temp and pressure.
First step in stage 4 was cutting for larger valves. For those of you that don't know what this entails it is A LOT of work. The actual cutting isn't to bad, but then you have to install new valve seats, report all the bowls to blend them in, do a new valve job, relieve the chambers for the bigger valves, cc chambers now to see what size they are, maybe mill to bring them back to size (I didn't, I wanted the extra volume to bring compression down a little bit). Now in reality if you were gonna do this this step would come first, except for the new seats you're not into it much more work than before, especially since cutting out for the new valves removes a huge amount of material from the bowls, so you have to spend less time porting Ok now with the 2.02/1.6 standard valves with a 3 angle valve job and a 10* back cut on the valves the flow numbers were :
Lift. Intake Exhaust
.1 72.4 47.6
.2 135.1 101.0
.3 201.3 140.2
.4 237.8 171.1
.5 264.6 187.6
.6 266.1 192.6
As you can see the heads reeaally liked the bigger valves. Though keep in mind that this is after extensive porting, just cutting for bigger valves and going would not get you these kind of numbers. Right now these are a kick but set of heads that would make a lot of power on any streetable small block. Intake runner volume is now between 190 and 195 cc's so you've still got good velocity for the street. Combustion chamber volume is 68 cc's. right now we're at about 70.5% intake exhaust ratio.
For the next Step I used manley pro-flo's to see if their vaunted necked down swirl polished valves really worked.
Lift. Intake Exhaust
.1 82.5 52.5
.2 145.6 111.8
.3 212.9 150.1
.4 245.4 178.6
.5 269.2 190.9
.6 270.6 195.2
As you can see they performed almost exactly as advertised, gaining a lot of low lift flow and tapering off, but with still a small gain at higher lifts. Well worth the cost i'd say, especially since they don't need any extra machining, so the costs are offset some.
More to the point, at this point they outflow AFR 190's pretty much throughout the lift range . Now good news bad news time. You can do almost all this yourself at home, with the exception of cutting for the valves and valve job (unless you've got a full machine shop at home). Bad news is that to do it right you've got about 200 invested in tools at the very least. And a dremel will not do it for you unless you'd like to spend about 100 hours. You'll need a real grinder with some good bits for gutting hard metal as well as sanding bits etc. The machinework alone will cost around 500 just for the stuff that isn't really DIY. Look for another 500-600 in the porting department to pay someone else. This is mostly due to the fact that the heads are iron, so take a lot more work to port. If you go this far be very careful not to overheat these heads, they were pretty thin wall to begin with, now in some places they're very thin.
Now for the fun part. The full competion port. In this step I ground out the humps (not totally, but almost) for the valve guides and inserted bronze guides. I also filled the egr passage with alloy (thanks to Joe mondello for this idea, worked so good on my olds heads i thought it would work here as well). In addition I welded up the divot where the valve studs intersect the intake ports and flattened it out. THIS WAS A BIG PITA!! Was this worth the time. Not unless your in a division that requires the stock heads but allows this much work to them. Flow numbers went up 25 cfm on the intake and 18 on the exhaust at peak. To me that's not worth it for close to another 15 hours worth of work, and I'm not sure how much I'd trust 'em to hold up on the street with that much done to them. I hope this series has been enlightening for all of you. Oh BTW the heads made 450 hp with a comp cam, around 350 with the stocker and 1.6 rockers. Next I'll probably do a quadrajet series over on the carb board as the fuel injection crowd seems to be pretty well sorted out.
__________________ Back in business, working on the Formula again. 409 Stealthram, 58mm tb, Ported systemax 2 heads, custom cam, 32lb injectors, 2 stage NX kit 250 total shot. Torque arm, control arms, lca's, panhard bar, headers, exhaust, etc etc.
Expanded 6E tunerpro Definition file available at
[http://home.comcast.net/~rhuarc1/pwp...6Eexpanded.xdf
Was, rhuarc30, moved to Il, L98 iron head part 4 finally up. Check it out on the TPI board. http://www.thirdgen.org/techbb2/show...hreadid=183264
Dunno, I could paste 'em all together for a tech article if people want it, Just kinda dissapointing w/o pic's. I could spell it out a bit more I guess.
Originally posted by rhuarc31 Dunno, I could paste 'em all together for a tech article if people want it, Just kinda dissapointing w/o pic's. I could spell it out a bit more I guess.
I'd have to vote YES. 270 on iron L98s is damn impressive. Did you measure the runner cc's after you were done?
Re: l98 iron head project part IV (Finally) VERY LONG
Quote:
Originally posted by rhuarc31 ...Intake runner volume is now between 190 and 195 cc's so you've still got good velocity for the street. Combustion chamber volume is 68 cc's...
Re: l98 iron head project part IV (Finally) VERY LONG
Heh, wow you did go back far to bring this one back from the dead. It's a Zinc Aluminum alloy that Joe Mondello sells, I'm sure you could find it other places as well. You can melt it down in a black iron skillet with a torch if you need too. I have also heard of people melting down cast pistons and using that, but I've never seen it done.
. Now good news bad news time. You can do almost all this yourself at home, with the exception of cutting for the valves and valve job (unless you've got a full machine shop at home). Bad news is that to do it right you've got about 200 invested in tools at the very least. And a dremel will not do it for you unless you'd like to spend about 100 hours. You'll need a real grinder with some good bits for gutting hard metal as well as sanding bits etc. The machinework alone will cost around 500 just for the stuff that isn't really DIY. Look for another 500-600 in the porting department to pay someone else. This is mostly due to the fact that the heads are iron, so take a lot more work to port. If you go this far be very careful not to overheat these heads, they were pretty thin wall to begin with, now in some places they're very thin.
