home ported 243 flow #s'
Thread Starter
Teching In
Joined: Aug 2005
Posts: 41
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From: JAX, FLORIDA
home ported 243 flow #s' This is a comparison between a stock 243 heads and a head i ported at home.
It was flowed on a superflow bench, stock valves'. intake ported to a 215 cc.
stock intake/ h. port intake
1. 63.0....62.7
2. 134.6..135.4
3. 191.4..195.3
4. 232.9..242.4
5. 260.5..274.6
5.5 253.9..266.3
6.0 247.3..257.9
There is a slight increase on the intake. after 5.0 of lift both heads take a nose dive. Any theories? i can't remember what size bore adapter was used. They were flowed about 6 months ago. Can an improper bore adapter cause this? I could possibly explain my ported head taking a dive ( i screwed it up) but the stock head did the same. I have never seen the numbers of a 243 drop after 500 (barely increase, but not drop)
stock exhaust/ h ported
1. 56.7...54.4
2. 116.0..117.8
3. 156.7..166.0
4. 174.9..188.1
5. 183.5..198.0
5.5 186.4..202.6
6.0 189.2..207.1
A little better on the exhaust. Is it woth while bolting the h. ported heads on?
Any opinion if there will be any gains? I wanted to install it with a tr 224/224 112. ls6 intake and lt's thanks guys i hope i can hit my goal...... 400!
It was flowed on a superflow bench, stock valves'. intake ported to a 215 cc.
stock intake/ h. port intake
1. 63.0....62.7
2. 134.6..135.4
3. 191.4..195.3
4. 232.9..242.4
5. 260.5..274.6
5.5 253.9..266.3
6.0 247.3..257.9
There is a slight increase on the intake. after 5.0 of lift both heads take a nose dive. Any theories? i can't remember what size bore adapter was used. They were flowed about 6 months ago. Can an improper bore adapter cause this? I could possibly explain my ported head taking a dive ( i screwed it up) but the stock head did the same. I have never seen the numbers of a 243 drop after 500 (barely increase, but not drop)
stock exhaust/ h ported
1. 56.7...54.4
2. 116.0..117.8
3. 156.7..166.0
4. 174.9..188.1
5. 183.5..198.0
5.5 186.4..202.6
6.0 189.2..207.1
A little better on the exhaust. Is it woth while bolting the h. ported heads on?
Any opinion if there will be any gains? I wanted to install it with a tr 224/224 112. ls6 intake and lt's thanks guys i hope i can hit my goal...... 400!
To be honest the numbers I have seen usually go up above .500 . Let me ask how did you screw them up ? Also the 243 heads what cc are they as this will change your current compression and with that size cam you are a good candidate to raise compression . If you have not read up on it yet search the clay method and think about raising your compression .
Thread Starter
Teching In
Joined: Aug 2005
Posts: 41
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From: JAX, FLORIDA
i thought i had screwed up the head i ported because i saw the #'s drop after 500 lift. but the stock did the same. im putting them on with a tr 224 112 cam and thinking about shaving them slightly .010 to cleen them up
I don't think you messed up anything on the head, simply because the unported flow numbers follow the same trend. You did indeed improve the flow, for a modest increase in port volume.
What kind of flow bench was this on? The reason I ask is because if the bench was too small for the job, it may not have been pulling the test pressure on the port, and may have been falling off. This would cause a drop in measured flow at high lifts.
I think your heads are OK. I question the test equipment.
What kind of flow bench was this on? The reason I ask is because if the bench was too small for the job, it may not have been pulling the test pressure on the port, and may have been falling off. This would cause a drop in measured flow at high lifts.
I think your heads are OK. I question the test equipment.
Joined: Apr 2006
Posts: 3,890
Likes: 1,137
From: Grand Rapids, Michigan
If you look at Thunder's website, they have a dyno test on a '98 M6 car with STOCK heads and it pulled nearly 400 HP at the wheels with roughly the same mods as you have and the same cam. You're looking at closer to 420 in my opinion. I'm installing the same cam in the next month or so. If you want better flow out of the heads and you DIDN'T narrow the valve guide bosses, go back in and do it. It should be worth 6-10 CFM across the board.
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Thread Starter
Teching In
Joined: Aug 2005
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From: JAX, FLORIDA
Yeah i did narrow the valve guides to a radius and removed the rocker stud "hump". Wich i guess would approximate to about 4 cc of material removed in the chamber. The runners look pretty good (i'll post a pic after i get off work).
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Thread Starter
Teching In
Joined: Aug 2005
Posts: 41
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From: JAX, FLORIDA
No ive really never thought of doing it for money. The market is so competetive and there are so many good affordable heads out there. It took me forever to do that one head. I got those 243s' at a really good price and couldn't afford aftermarket port work so i did some research and went at it. I'm just looking for an improvement over stock 243s' even if its only like 8 rwhp.
Thread Starter
Teching In
Joined: Aug 2005
Posts: 41
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From: JAX, FLORIDA
Lol, na man im just a dude with a dremel! Some people dont like dremels for porting (it takes a long time) i think its perfect for the first time home porter. I takes off very little material ata time and gives you much less of a chance to screw up.
Last edited by raymondvp45; Feb 28, 2007 at 07:30 PM.
Thread Starter
Teching In
Joined: Aug 2005
Posts: 41
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From: JAX, FLORIDA
Yeah, it took me about 8 hours per port. Alot of patience, but like i said the advantage with a dremel is that you can work it SLOWLY without taking too much off. i hope it was worth the work.
