241 heads flow numbers

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Oct 16, 2015 | 11:50 PM

Puke13

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241 heads flow numbers

I am thinking about having my 241 heads ported and polished, and doing a cam swap on my 02 ta.

The shop said they flow around 230 cfm stock, and the clam they can hit 265+ cfm.

What have you guys seen out of these heads?

Oct 17, 2015 | 07:28 AM

HCI2000SS

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From: Howell & Fenton MI

I've seen them go close to 300 cfm

Oct 17, 2015 | 07:59 AM

A.R. Shale Targa

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If you're gonna pay to have them ported then find a CNC shop like TEA or Texas Speed to get 290 or so from them. If you just want the 265 number then pick up a set of 243/799 heads for 400 bucks and have a valve job and surface done. Those start at 265 plus have smaller and more efficient combustion chambers

Oct 17, 2015 | 08:49 AM

96capricemgr

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Flowbenches will be the perfect tool when engines start holding the valve open all the time and develop steady vacuum at the port rather than reciprocating piston.

Oct 17, 2015 | 01:46 PM

Felix C

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Peak flow is not the really important metric. Look at flow from .200 to cam peak. Ask shops for a flow chart on work they have done. Confirm intake or pipe on the inlet.

Oct 19, 2015 | 07:55 AM

gagliano7

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From: Monroe,NY

Here are #'s from AI

Attached Thumbnails

241 heads flow numbers-ai219ls1flowsheet-1-.jpg

Oct 19, 2015 | 08:06 AM

Darth_V8r

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That's not bad for 241's. Certainly seems real and not inflated by using a larger bore plate, etc

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Oct 19, 2015 | 06:26 PM

Felix C

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I see the main issue with the 241 being the combustion chamber is more effective on the 243 which I believe does not show up on a flowchart.

The only company that addresses this is AI HI work where the chambers are welded/filled etc.

But how much power is that? I do not know. It is a budget head to invest no more than $1500 on in my opinion. Less the better.

I asked in another thread how much they gain from a good valve job. Let me find that link.

https://ls1tech.com/forums/generatio...valve-job.html

Oct 20, 2015 | 07:11 PM

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BrownMK3Kid

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I just bought some 241 heads for my build and some good info in here! thanks !

Oct 20, 2015 | 08:25 PM

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MonmouthCtyLS7

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I've seen some good numbers from AI 241's.

Oct 21, 2015 | 08:19 AM

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farmington

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From: Little River SC

if you double the intake airflow you get an approximation of the HP a set of heads can handle, ie, 265cfm could possibly produce 530 crank hp.

Oct 21, 2015 | 09:26 AM

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dkota1968

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I had a set of cartek 853(basically the same as 241) 2x heads, 2.02-1.60 valves. Dont remember size of runners but flowed 303cfm intake side at .600 or .650. Never got them on because motor commited suicide and i just bought a whole motor. The flow bench sheet was from another machine shop not cartek.

Oct 21, 2015 | 09:44 AM

#14

elephantrider

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From: round rock tx

i got right at 300cfm on a set of worked 241's. putting down close to 450 wheel with the ms3 cam.

Oct 21, 2015 | 10:31 AM

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Darth_V8r

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Quote:

Originally Posted by farmington

if you double the intake airflow you get an approximation of the HP a set of heads can handle, ie, 265cfm could possibly produce 530 crank hp.

That is true, but the flow bench number can be manipulated by the size bore plate you use. Tony showed it on an earlier thread on his 220's using a 3.9 bore vs a 4.0 bore gaining 10-20 cfm (can't remember the exact numbers).

I tend to see a lot of ported head flow numbers in the 300 range, but they don't all seem to perform the same. In general, I would say I see Tony's and Brian's 300 CFM running stronger than most others.

Quote:

Originally Posted by elephantrider

i got right at 300cfm on a set of worked 241's. putting down close to 450 wheel with the ms3 cam.

This seems to be more the norm. 300 cfm heads giving mid to upper 400's power levels, depending on cam, intake, etc. Call 450 at the wheels 530 at the crank?

A very well optimized 346 build is good for about 500 at the wheels, and that's even if the heads will flow 320. Sometimes a bit better than 500.