01silvy

Hey guys, I have been holding onto a pair of 241's for a while now and i hope to be shipping them out to AI to get worked over soon. I bought them off of ebay and they supposedly came out of a comaro that had 30k miles on it. They look good and are clean but one of the exhuast valves are not seated into the seat as it should be. I tapped it with a hammer slightly and it started going in to its resting position but i stopped because i didnt want to cause anymore damage if something was wrong. Either way i am wanting to get their 219cc porting package done to them and get the PSA long life springs since i will be running the 212/218 low lift cam with my setup. My questions are:

1. Should i get all new valve guides installed since im not sure of the history of these heads? Keep in mind the ultimate goal of my build is decent NA power but is a reliable DD.

2.What CC should i go with the combustion chamber if i am shooting for 10.2:1-10.5:1 compression? My engine will be a L33 running wiseco flat tops.

Thanks guys.

RS/SS 4.8

iTrader: (13)

That "hanging" valve is a bent valve. Hopefully u didnt do more harm by tapping it in lol

BigKID

iTrader: (5)

You should have just marked that valve and had AI have a look at it when you sent them the heads. I agree that it was probably a bent valve.

For CR, assuming a 3.78 bore, .01 out of the hole and a stock LS1 MLS gasket, I calculate a 61cc chamber at 10.55 to a 64cc chamber at 10.15.

I am interested to see how you like the 241 heads after you get them back from AI as I have looked into them for a set of 241 I have to put back on an LS1 I plan to build for my Tahoe. I was debating getting them done for my Silverado which I recently rebuilt but decided to go with an aftermarket head instead.

gamble686

iTrader: (3)

Honestly not worth your time or money to get the 241s worked over. Especially with a bent valve. 243s are far superior and can be had for less than $300 these days.
Keep this in mind.
The very best AI 241 heads will make 35-40hp more than stock 241 heads.
On the other hand stock 243s will make 15-20 more hp than stock 241s.

01silvy

After about 2 taps i rralized it was probably bent and stopped lol. The valve face looks good though. It dosent look like it contacted anything.

01silvy

Thats the setup i am looking at too. I want the 3.78" wiseco's and stock MLS gaskets. I am figuring i should shoot for 61cc-62cc chambers. It still may be a little while before i ship them out. Right now i am getting a idea on the head work i need to request and what cam to run along with it. Will keep you all posted though! Thanks for the help.

01silvy

I know 243's are superior in almost every way but i picked these up about a year ago for like $175. And if these heads pick up 35-40 more hp than stock i would take that all day long. I am sort of relying on the healthy boost in compression to help with the low end power.

gamble686

iTrader: (3)

Wi the 241s you will spend at least $795 with AI for some bad *** 241s. Which is great they make great heads. However, SDPC makes some 243/799 heads for about $550 that I bet will beat the pants off your AI 241s. For less money and you can resell your 241s.
https://sdparts.com/details/scoggin-...er/x88958765-2
Or these with smaller chambers
https://sdparts.com/comment/693#comment-693

01silvy

It says those are sold individually at $599/piece... I already have 241's and thats what im going to stick with for my build. Thanks though, anymore advice/tips?

gamble686

iTrader: (3)

Oh wow I was always surprised they were so so so cheap. Didn't realize they were sold individual which makes a ton more sense. I would go to 64cc for good compression with those flattops.