nastychevelle

iTrader: (7)

Has anyone tried raising the runners on an ls1 head? I haven't seen much on the topic. I just picked up a single 241 head I plan to mess around with the ports on and one of the things I am going to try is doing a raised runner port. I will see about getting them flowed before and after if I can find a shop to cooperate and not charge me an arm and a leg.

KCS

iTrader: (20)

How do you intend to raise the runners?

nastychevelle

iTrader: (7)

Using expoxy on the floor and if I need to putting epoxy under re valve cover area so I have room to raise the roof

nastychevelle

iTrader: (7)

The plan is to roughly keep the same port shape and size just raise it. Im still torn on how much to raise it. Im thinking somewhere between. .100 and. 250

Patrick G

iTrader: (14)

You run the risk of having your valve spring pockets break off under the thinned out roof. Epoxy won't be strong enough. FWIW, 243 heads and all aftermarket LS1 heads have raised roofs and better short turn radii.

nastychevelle

iTrader: (7)

Yeah I was wondering about that. How much room do you think is there to safely remove?

bww3588

iTrader: (49)

none....i wouldnt raise it at all. GM spent tons of R&D and money desigining the GEN III head, its pretty good where its at. if you raise it at all, like PatG said, you run the risk of your valve spring pocket falling apart. especially if you use a stronger spring with a high lift/duration camshaft.

KCS

iTrader: (20)

Like already mentioned, removing material out of the roof isn't a good idea since there isn't much material there.

There is a pretty popular vendor on here that had issues with an earlier version of their CNC program cutting too much out of the port ceiling right under the rocker and it caused the rocker arm to rip the port roof right out of the heads.

Instead, you could probably take material out of the sides of the port to get the port size back, just be cautious of the pushrod pinch area.

studderin

iTrader: (28)

if you weld a TON and build the spring pocket up you could

garygnu

I have seen pics of how the prostockers in the 80s would raise the ports of stock heads,lots of work .I believe the trick flow head has a little higher port floor then a stock gm ls1 head.

nastychevelle

iTrader: (7)

Since this is strictly for fun and that is all i bought the head for (to play around with) i went ahead and epoxied the floor and the top of the roof. since the head will never be ran and is strictly a research piece i figured why not. here are some pictures of the epoxy with no other work done (waiting for it to harden) i didnt take note of how much epoxy i added but i'd say it was probably in between .100 and .150




and here is my roughly cut in exhaust port. i just did a very minor clean up and took the bump out right before the valve guide. i also did a little rounding of the valve guide as well as blending the valve seat into the port .


sorry for the cell phone pictures everyone!

tomorrow i plan on smoothing the epoxy out and beginning to raise the roof (while trying not to get too far into the rocker arm bolt hole!).

nastychevelle

iTrader: (7)

i did a little work on the intake today, raising the roof and then removing the rocker bolt bump. i also went in and smoothed the epoxy out and rounded it into the chamber.

mark21742

You REALLY have to watch that bump in front of the exhaust valve guide, that hump is there because there is a dip in the water jacket where it goes under the spring seat

mypoorLS1

iTrader: (4)

Are you just gonna use it for flowbench testing? What about the intake manifold?

studderin

iTrader: (28)

theres other spots your limited to on that casting. you built up the shortturn, that can be good. but your going to hit water shaping before you get to use that work. And you can't fix that east fix. The stock valve and port its limited. Then that casting doesn't have the bowl to use the roof raised. Dig it out and you can have somone good weld it up, still gona have the deal with the spring pocket, and the rocker stand, thats gona be weak and not play well for putting some spring, and cam on the motor and cause problems. You got the cart way before the horse, what are you tring to do? if you have no engine size, rpm, or even the valve size you making this port for. take a few steps back and work on your grinder control on a different port, If your just messing around with this. Get some tools to start measure the sizes of the stock port and see what you find there. Work on the just the valve job and that end of the port, and your be way ahead of what your trying to learn.