Thinking of extrude hone my stock upper H.O intake...what can I open the TB to?

Highbredcloud

Active Member
Mar 4, 2003
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Palos Hills, IL
any ideas? :shrug: what can I have the plenum opened up to on the stock H.O upper intake? I always thought 65mm was max but I was talking to one of the techs today and he told me I can go 70mm...is there enough meat on the intake to handle 70mm? :shrug: or was that dude just full of it? BTW: I really want to use stock part setup for this combo so getting another intake would be out of the question...this is just something stupid I decided to do. Any input would be appreciated.

-Greg

UPDATE: 3/18/04

I have spoken with Extrude and Hone and was told that I can get the upper intake to flow at 200-205cfm and with more work can get it to flow about 220-240cfm range but that would be pushing it...NOW here is my question...would this be worth doing if I am going to run stock E7TE heads ported...? From doing my research I have found that properly ported E7 heads should flow between 200-215cfm on the intake and 155-170cfm on the exahust...SO with that in mind would having the stock intake extrude hone to match the flow of the heads benefit me? Currently the stock upper flow about 185cfm and I have a Systemax 1 lower that flows an average of 210cfm...SO would the upper still be a bottle neck and should I have it extrude and honed? or am I fine? The reason for me asking is that I always see intakes flowing less than the heads...for example GT-40 style intake flow about 200cfm...and heads usually flow more than the intakes...Hopefully you guys understand what I'm trying to ask here...BTW: I AM DOING AN ALL STOCK STUP UP...USING FACTORY CASTINGS so I am not switching intakes...Thanks again... :flag:
 
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I would say you can do 70mm, but no larger. The stock EGR spacer can be bored out that far too. I have one in front of me I did myself and the one on my car my dad took out to 65mm to match my current TB.

Wait a minute, getting the stock upper Extrude Honed is going to cost about what you could get an Explorer intake for.....
 
65ShelbyClone said:
I would say you can do 70mm, but no larger. The stock EGR spacer can be bored out that far too. I have one in front of me I did myself and the one on my car my dad took out to 65mm to match my current TB.

Wait a minute, getting the stock upper Extrude Honed is going to cost about what you could get an Explorer intake for.....

Thanks for the info...and yes the upper alone will cost $350 plus shipping...however, the upper intake is suppose to flow around 220-240cfm...I need to get better confirmation on the flow numbers before I decide for sure...I want the stock castings for the sleeper look...
 
$350 and then some?! Whoa, I take it back, you can get a used Edelbrock for that!

Well, even if the upper does flow 240cfm, that wont help your stock lower flow more than 190cfm fully ported. The good thing about the Explorer is it flows around 210-220cfm and you can use your stock 5.0 HO intake plate to make it look very close to stock. Thats what I plan to do if I dont get a Performer. What the smog Nazis dont notice wont hurt me. :D

I'm just trying to throw some other ideas out there because I know how much it sucks to buy stuff you dont need.
 
65ShelbyClone said:
$350 and then some?! Whoa, I take it back, you can get a used Edelbrock for that!

Well, even if the upper does flow 240cfm, that wont help your stock lower flow more than 190cfm fully ported. The good thing about the Explorer is it flows around 210-220cfm and you can use your stock 5.0 HO intake plate to make it look very close to stock. Thats what I plan to do if I dont get a Performer. What the smog Nazis dont notice wont hurt me. :D

I'm just trying to throw some other ideas out there because I know how much it sucks to buy stuff you dont need.

LOL...don't think I forgot about the lower intake...holley systeMax I intake flows about 220cfm...untouched so I think that would be a good match for the extrude hone upper...Plus, this is really a project to find out how much power I can get out of stock looking setup...My goal is when someone looks at my car not to notice anything in particular as far as heads and intake goes...what others don't know the better for me... :D
 
Cut the intake and half or have it done then port it....cheaper.

Like the others I still think your crazy to spend that kind of money on a stock manifold, but I see your on a quest....
 
I like the sleeper idea myself - to each his own. Keep us informed about your final results. Oh, a lower with my "standard" port job (small welds on #1 & #5) was flow tested at 195 cfm average by Greg at XSR cylinder heads and he recently got 250cfm out of a stock lower (welded up), so you can get very decent flow from the stock lower.
 
Tmoss: I read about his recent success and if the flow numbers are correct I am impressed...A lot of work but good results. I picked up systemax I lower intake for about the same price as it cost to have you port one and ship it...30cfm is not worth the extra $$$ espcially when the stock ported heads won't see more than 220cfm...

Rick 91GT: I agree with you...I must be completely nuts trying to do this but I have always wanted to see how far I can go with the stock castings before I can make an opinion in regards to power vs money issues...I'm not looking for brand new things...infact I am going used parts on most of the combo to save some $$$...BTW: the intent of this project is to make the car apper stock...and the big welds across the intake will definately lose to appearance of "stealth mode"...and that is really important to me...what people can't see will ONLY benefit me...
 
highbredcloud - cool stuff man, i'm doing the same thing. it's definately not the most cost effective way to go but, like you said, i love the idea of popping the hood to show off my "100% stock" motor ;) let me know what route you decide to go on the upper (extrude hone or cutting & porting) as this is something i'm trying to decide myself. i'd hate to pay for the ex. hone just b/c it could go toward a better intake one day so i'm trying to get info on cutting. keep us posted.

-steve
 
Just a little update: called both branches of extrude hone today, the PA one and the one in CA and I was told that the stock upper flows about 170cfm...I was always under the impression that the stock upper flowed more like 190cfm...both the techs concured the same info except one guy at PA told me that after extrude and hone I can expect 200-205cfm with the TB opening up to 70mm...I later told him that the tech at CA said I should expect about 220-240cfm...well later the same guy told me they can try as much as possible to have the upper flow between the 220-240cfm range and open up the TB plenum to 75mm...Right now I am sort of confused...I thought that extrude and hone gave the same results no matter what but it seems like you get to choose what you want out of it and I want the best flowing upper intake I can get for $350.00. Supposedly all I have to do is include a letter with the sizes of what I want the TB plenum opened up to and the approximate cfm range I want and I should get that...I don't know if that sounds right to me...sounds a little fishey...anyone know about this?
 
Greg also tested a stock upper and had the lowest runner at 170 cfm and the highest at 195cfm, so average is gonna be closer to 190 than 170. Caveat Emptor on what you get from EH - make sure you get what you need.
 
It's all in how long they're willing to let the machine run before it erodes away the walls completely... Same as hand porting, just how brave are you.

Kind of suck if they punch a hole in it in the top or front and for $350 you have a stock looking intake with a little weld spot on it to explain away :)

Jamie
 
Was just looking on Google and found this forum. I am thinking of doing the same thing with my "91. Get this, it's an AOD. I know this sounds funny, but looking stock is the way to go. Here's the catch. If you are looking at going this route, you shouldn't go any higher than 65mm on your TB unless you are going with larger heads and perhaps cam. Your throttle body won't appear stock but worse, you'll lose your port velocity and hurt the low-end. If you're going to have stock heads (even ported) they won't leave you with enough flow volume to get the most horsepower out of your combo. If weight is not a concern (it is for an AOD car, so aluminum, here we come), then you might find a set of ported, first-generation GT40 heads to go along with it (not P's because they are more expensive and requre a different header), match port them with your intake and see what happens. Use 1.72 roller rockers, and cut the oil baffles out of the rocker covers to make them fit. You should get right around 300 hp, gobs of torque :nice: and the stealth factor would be through the roof. Make sure you use a 73mm C&L MAF. Low key and a quality piece to boot.
 
For Stock Ported heads i would look into PowerHeads (www.Powerheads.com). E7's flow 217<in> and 174<ex> at .500 lift... Even better would be the 351w heads which flow 229 on the intake side while still retaining a stock look! Im not a sales rep, just had great success with them!

Also about heads flowing more than intake.... Heads will ONLY flow as much as the intake can flow!!! So get that intake flowin!!!

I've also seen cut and welded intakes look untouched by grinding down the welds carefully and painting the intake to match the stock color again. This or extrude hone are the way to go! Good Luck with your project and keep us updated!!!
 
tmoss said:
I like the sleeper idea myself - to each his own. Keep us informed about your final results. Oh, a lower with my "standard" port job (small welds on #1 & #5) was flow tested at 195 cfm average by Greg at XSR cylinder heads and he recently got 250cfm out of a stock lower (welded up), so you can get very decent flow from the stock lower.

I just sent you an email requesting a quote to port my factory intake on my 89 stang.