Intake & IJ Porting @ Home

[32valvZ]

I know there are a bunch of you who do this professionally....I dont know the costs of having this done, but I imagine is pricey. So, is it realistic to think a guy, with proper tools, could do this on his own at home?

I've done some porting on a couple sets of iron heads back in the day, pocket porting and bowl blending... but never fooled with aluminum.

So do it at home or pony up and send it to the pros?

[XfireZ51]

I think if ur talking top end, then yeah u can do that but expect to fix some holes. Ask me how I know.
Cylinder heads I would send to someone like Marc or Pete.

[Paul Workman]

I did ALL the porting on my LT5. And, after several experiences with cast iron heads and intakes on SBCs (decades ago!), aluminum is a breeze in comparison!

With proper tools and a professional welder, one capable of doing aluminum (especially intake runners, etc, and some specs, it can be a DIY project for the right person.

PM me.

10661

10662

10663

[jss06c6]

Yes, you can do it yourself. Be prepared for lots of time as it's best to go slow until you get the profile down. Suggest a good flex shaft die grinder (Otto Frei). Makes the work much more enjoyable.[ATTACH]

Suggest you send heads to Pete or Marc as Dominic indicated. I port matched mine (primary only), which is pretty straight forward, but full porting of the heads needs some experience.

Sent from my SM-G950U using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[jss06c6]

[ATTACH]

Sent from my SM-G950U using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[32valvZ]

No heads... just intake and IJ housings... is it worth doing just those? And why will I need a professional welder??? And what holes will I need to fix? Sounds already like I better pay a pro .....:o

[Demps]

Plenum & injector housings with 4.10s. Quite a riot. 412 rwhp.

Talk to Corey Henderson.


10666

Ted

[XfireZ51]

Top end porting is the “gateway drug” for ZR-1 owners. It shows u how throttled this motor was.

[Paul Workman]

No heads... just intake and IJ housings... is it worth doing just those? And why will I need a professional welder??? And what holes will I need to fix? Sounds already like I better pay a pro .....:o

Pro or a welder skilled in TIG welding aluminum runner techniques is important primarily for a DIY head porting job, & I have one of my 1990 heads sitting on the floor of my office to prove it! (As Marc Haibeck says, "If you don't punch trough (the runner) at least once, you're not trying hard enough!)

THAT said, you can realize the lion's share of the HP (400 rwhp) benefit of porting by doing the top end only and port matching the heads (see my photo - above post). And, if you're careful to not veer from the centerline of the casting, you won't need to have that welder guy "on retainer".

Some snap and ball gauges, select carbide burrs, a quality die grinder (I prefer the Snap On pneumatic for best control, but Makita makes a constant speed electric that many prefer), a steel straight-edge...and with some techniques you will be fine: nice winter project if you don't get in a hurry.

Then, to top it off, you'll need a dyno tune for best reaults OR Marc can fix you up with a calibration that will "plug and play & yeild almost 100% of a good dyno session, depending on your exhaust config.

[XfireZ51]

I tried “hard enough” at least twice. Thx to Al, I didn’t have a massive vacuum leak. =D> ;)

[Paul Workman]

Top end porting is the “gateway drug” for ZR-1 owners. It shows u how throttled this motor was.

:thumbsup:

John, Dom is soooo right on! I went from 327ish rwhp to est. 400+ rwhp with top end porting and headers. It completely changed the "attitude" of the car. And, the best part is, there is NO LOSS OF DRIVE-ABILITY as result! Completely stock idle. No hit on gas mileage, AC unaffected in traffic...what's not to like?

Need confirmation (of a sort) for this modification? For the LT5 gen-II, Lotus did away completely with the dual runners AND the Secondary Port Throttle concept. The motor made 550 crank HP(?) with a mild cam lift mod, if I understood Graham Behan correctly.

Before and after (including head porting, SW headers, SW "X" pipe and 3" exhausts