polishing/smoothing the intake passages and underside??

[Modern Motorsports Ltd]

Time permitting I'm planning to do some 'smoothing' ( I saw that as I doubt I'll get to full blown polishing) on my intake runners on my victor Jr. for my EFI (dry manifold) install. I want to enhance flow as well as reduce heat transfer from intake to the incoming air. I also plan to make/install a small sheet metal shield on the intake underside to stop hot oil from splashing on the underside of the intake and transmitting heat to the intake. I see the results as free hp/efficiency so if I can fit in these mods I'd like to.

 

What's the best tools to smooth out the intake runners and 2nd part polish if in fact I get that far? I have a single speed (28k rpm) Dremela and an air die grinder. I know a true polish would have the greatest effect but the time req'd will not likely be spent to see my own reflection in mirror finish ports

 

I'll have to check my Eastwood catalog later on but thought I'd get this thread started

[DavyZ]

Ross, you also might want to check Summit Racing and see if there is a cost advantage there. Eastwood and Summit are the two places I would check.

[Modern Motorsports Ltd]

I wanted to see what's offered/labelled as such but will likely source the 'bits' I need locally.

 

A great polisher (owns some gold medallion Z's) just rec'd http://store.yahoo.com/toolsplus/sai45007.html

 

for the full job......looks pretty versatile, will check it out when time comes

 

I'd post the pic here but I haven't reinstalled Netscape yet and IE is a PITA for the 'view image' etc.

[Guest Anonymous]

I was going to suggest Eastwood as well. The air die grinder would be the tool of choice, the dremel is a touch light I think. Polish smooth, but not shiney, a smooth wall with some texture to it will give better automization than one thats totally smooth and mirrored looking, and least thats the word from the articles I've read on it. I've only port matched to gaskets, not done much else.

 

Lone

[Modern Motorsports Ltd]

"Polish smooth, but not shiney, a smooth wall with some texture to it will give better automization than one thats totally smooth and mirrored looking"

 

This will be a dry manifold so atomization won't be a consideration unless I go to a wet nitrous setup later on

 

Ideally mirror finish would be great from some mech/chem eng engine builder buds but not realistic

 

Anyone know who offers the underside sheet metal 'shields' to keep the hot oil off the underside of the intake? I'd like to get one at my favourite auto shop and copy it as I have some Xtra scrap and return....

[clint78z]

Here is a good article on porting it has all the stones and tells you the roughness. You are right about have a certain amount of roughness to promote fuel atomization.

 

Heres a good link http://home.coffeeonline.com.au/~camaro/diyport.htm

[Guest Anonymous]

Opps, old guy thinking in terms of carburation again, sorry. Your correct, dry then the smooth but not shiney walls would have less or no effect. How expensive is like Extrude honing? Just curious, it looked like a pretty cool process. Funny thing I read, years ago in Nascar Smokey Yunick was always known for one who has a different interpretation of the rulebook. (His exploits are many and humourous). Anyway, the rules said no hand porting or polishing of the heads they were using at the time. He interpreted that to mean, that if he pumped a slurry of abrasives through the ports then it would be ok. He said it worked well, even to good, he ruined a head when it ate through the port. It took a race or two before it was discovered. A lot of years later I saw they did the same with extrude honing. If you find any articles about the guy check it out, his 'interpretations' on Nascar rule of the time are priceless.

 

Regards,

 

Lone

 

[ May 08, 2001: Message edited by: lonehdrider ]

[DavyZ]

Yeah, that guy is a riot! I have his "Power Secrets" book and I've read it a few times. He never really "cheated"; he just had a different interpretation of the rules. At least he was consistent with that...

 

Lone, the last time I looked at the price of Extrude Honing, I ran away. The process usually costs more than the part you want to modify...I know they are trying to recoup their investment costs, but sheesh! Force feeding toothpaste thru an engine part can't be that expensive!

 

David

[BLKMGK]

Extrude is what you'd want to do otherwise just do light porting to clean up. Extrude isn't that rude if it's something they already have a fixture for. I think the reason the cost can be high is the setup time and the low volume for us car guys. When it's an OEM like PorscheSVT or say an aircraft company that wants a couple hundred turbines done it's "cheaper". I've seen the process done, actually played with the gritty goo - it's wild! It was done to an intake manifold I owned, was about $200 but the inside was nearly mirror smooth and CFM not only went up but also balanced out. Depending upon th eapp the cost is worth it, obviously we're not trying to maintain a stock appearance in this case though are we?

 

I too will be switching to EFI, probably using my existing RPM intake. I will have bungs welded into it, maybe knock down some rough areas withan air die, and then not worry about it. The HP you'll pick up in this case is PROBABLY minimal and IMHO not worth the cost.

[Kevin Shasteen]

I agree about the cost -vs- the bottem line results. Remember; a pro-stock dragster and NASCAR routinely find themselves in the 8000-8500rpm range. Unless your car is gonna be running in that range you'ld probably be better off putting your money in light weight pistons, or in the bottom end; or a no holds barred ignition system of some kind.

 

Nothing wrong w/porting; but make sure you know what you're doing. I'ld strongly suggest reading David Vizard's book on "Building & Modifying the SBC Cylinder Heads". He constantly reminds the reader that an engine builder doesnt have to make ports bigger to obtain more airflow-instead the builder needs to know where to port & even more important-how to port the area you've decided to port.

 

If you want extra HP & aren't going to be in the 8000+ rpm range; you'ld be better off concentrating on light porting & deshrouding the valve's in the combustion chamber; if you find a head porter that knows what they are doing-you can pick up 30-50hp.

 

I have read good things about Extrude Honing; one of them is not how cost efffective it is! But if you are looking for that "Last bit of HP" & have the extra bucks-go for it!

 

What I finnaly learned from Vizards book (after reading it for the 4th time) is he relates the airflow in a port to a race car on a road; as that car approaches the turn-which is best for the car: 1)to approach the turn at full speed 2)or too slow down the car prior to the turn & to approach the turn on the inside of the turn?

 

Vizard claims-the air in the port is doing the exact same thing a driver does when they fail to slow down for that curve; likewise, if you cant slow down the air before it hits the turn w/in the port-the air will actually bang against the opposite port wall-this causes the port to flow air at a slower than needed rate...which turns an engine into a slow poke of an engine not making the desired power one intended. He claims what you want to do is attempt to allow the air to make as straight a turn as possible-to achieve this the porter has to increas the radius of the turn....to understand this you'ld have to see the pictures in his book.

 

I'ld stronly reccomend his book for anyone thinking about porting SBC cyl.heads. At least, by reading the book first, you'ld then have a better feel for what your needs are based on the engine you're wanting to build.

 

Kevin,

(Yea,Still an Inliner)

[Modern Motorsports Ltd]

No mention of porting here Kevin. Strictly smoothing out the surfaces on my intake. If I have some time I think it'll be quite worthwhile. Heat transferred from intake (stinking hot intake/no matter what design) to the incoming air will be reduced measurably if I can smooth it out decently. It wouldn't take a lot of work to reduce the surface area by 25% or so and if it works out and I get it polished quite well it'll only reduce heat radiated that much more. Free efficiency once done, I do a lot of driving so the efficieny is always something I try to keep in mind. More efficient=> less load=>less fuel req'd or MORE power on throttle. Some AEOTY candidates (anal eng. of the year/a true aware on a list of mine ) are looking at the potential gains.

 

Enjoying my recent GRM issue including the $2001 challenge The labour into the 'tobacco free team' (was dead clown racing) is unreal....he cut his intake in half to port and polish his runners and then rewelded....whew! Lots of neat 'stories' in that challenge article.

[Kevin Shasteen]

Ross,

 

Porting means many things to many people; however, the process of removing metal is the act of porting-regardless if its from the intake, exhaust or the cyl.heads: porting is porting.

 

So, if I understand you correctly; you're intention for removing metal from your intake isnt directly to gain HP but to thin the walls so that the intake will dissapate heat quicker-therefore internal temps of the intake will remain cooler....thus the final outcome being coller temps will result in more HP (better efficiency).

 

My only concern would be the amount you're thinking about removing; 25%? I've read where typical porting (of the cyl.heads) constitutes less than 5% of the port itself. What would be the after effects of removing 25% of the intake port? Would this thin the walls beyond their ability to resist cracking. Can you even remove this much metal to begin with. What effects on airflow would this have-specifically "pressure". An engine's ability to make power totally depends on pressure as it is pressure that pushes the air thru the ports & into the cylinders. Remember; its pressure that determines an engine's air/fuel ratio as it effects that air's "Density" on the air molecule.

 

I'm just rambling here & throwing out ideas; my thoughts are-a little porting is good but too much is not good as it diminishes airflow because of its effect in a negative sence if one goes too far: AKA-dimishing returns.

 

I'm no expert and would certainly never attempt to talk anyone out of an "idea". If I were you I'ld check w/companies that offer Extrude Honing...surely they keep these numbers (Spec's) in a book somewhere & should be able to answer any of your questions about how much metal can be removed & its effect on air/fuel mixtures in light of atmospheric pressure, even if you are using an EFI set up that is suppose to adjust for changes in atmospheric pressure-there is always a point in theory where you surpass the point of no return.

 

I'ld check w/multiple companies & not limint myself to just one company's response. If you get a collective of responses youre odds are better that the responses will either confirm their answers or will reject each other.

 

Definately interesting concepts; good luck/let us know what you find!

 

Kevin,

(Yea,Still an Inliner)

[Modern Motorsports Ltd]

Kevin, reread my posts. You missed my intent, a rough wall for ie. may have a surface area of 15 cm square even though in plan the area is only 10cm square. It is the roughness/undulations of the surface (ie. mountains/hills in microtexture) that increase the hypothetical surface area 50%. Reduce this surface area and heat radiated from this surface is less. Nothing new about my 'idea' and its proven simple thermodynamics by many. If you knew me you'd know I'm not in any way tied to a single company/expression The exact degree of gain is something being looked into but I know it exists nonetheless simply due to the significant gradient b/t our engine bay/intake physical temperature relative to our incoming air temperature so gains are their to be had. Same reason piston tops are coated to keep the heat in the bore pushing the piston rather than translating into the piston itself as wasted heat energy. Porting I've always interpreted as altering the overall contour/shape of something which is not my intent/just my take on 'porting'. No offense on use of 'porting', you tied several cylinder head references in their strongly hence my reply.

[DavyZ]

So what you're really doing is really "polishing" more than "porting," like the title on your post says, correct Ross?

 

[ May 08, 2001: Message edited by: DavyZ ]

[Kevin Shasteen]

quote:

---

Originally posted by Ross C:

[QB]...It wouldn't take a lot of work to reduce the surface area by 25% or so]

---

 

Ross,

 

I'm not offended as I am very thick skinned and would certainly never get miffed over something as small as semantics; I'm just trying to understand what you're talking about. I wasnt trying to convince you "I'm right/your wrong" as I was merely attempting to understand what your process is, what your intention is & what your final product will be...if I'm unsure of what you're doing by the words you've chosen-then others that read your post may also be confused.

 

The way I see it-as I read your post/the confusion lies in your choice of words; at least for me it does. Your quote above mentions reducing the surface area by 25%.

 

Either your reduction in surface area is referring to the reduction in the thickness of the intake port walls-which means removing metal and therefore decreases port pressure (raises the powerbands peak power); or are you referring to the reduction in CFM that the ports will flow, which refer's to the adding of metal to the port walls which would increase pressure (lowers the powerbands peak power).

 

Since you asked about Extrude Honing I assumed you were referring to the removing of metal...whatever term you want to give it.

 

I'm aware of porting/polishing (the act of removing metal) in the intakes as well as the cyl.heads; I only wanted to caution you about removing too much (25%) & wanted to know if you new how much could be removed(?) if you did know then I'ld like to know what is that amout, & what are their gains?

 

I'm not offended & I certainly hope I didnt offend you either: this is a discussion forum & not romper room-so you dont have to walk on egg shells when responding to anything I ever say. I always look forward to anyone's intelligent response as it is that response that keeps the discussion going till all info is obtained & everyone is smarter as a result of the discussion.

 

It sounded like you had an intelligent idea & I wanted to know the specifics! Talk to me w/details-how much metal/adding-subtracting metal/where is the adding/subtracting of metal taking place from? Are you removing it from the thickness of the walls or are you adding it to the port walls?

 

Kevin,

(Yea,Still an Inliner)

 

[ May 09, 2001: Message edited by: Kevin Shasteen ]

[Modern Motorsports Ltd]

Yeah Davyz 'polishing' as per subject.

 

 

If my posts have been hazy I apologize/I'm trying to maintain this verbosity to clarify it I hope.

 

Kevin, I think perhaps your confusing the cross sectional area of the actual structural portion of the intake as what I want to modify. 'surface area' is just that, surface exposed to the incoming air in the runners....you run your finger over cast aluminum and it's not smooth, just sand it down and you just reduced the surface area.....notice how a crumbly 'drier' cheese gets hard faster as it transpires moisture faster from it's rough surface than smoothy mozza , within a city block 100m long it may rise 25m and fall 25m to finish at same elevation (San Fran). That block has far more surface area to radiate or absorb heat with easily 11% more surface area than a flat one, our aluminum is far more up and down than this ie. A dead flat/level block in a prairie city has less surface area (your pythagoran theorem doesn't apply here/straight line, in San Fran you can pythagorize all day as the sum exceeds the single base plane) and consequently less heat can be absorbed or radiated.

 

My gains are not from removing material on the scale you describe but from smoothing out 1-2mm diameter and smaller casting 'bumps', not smoothing out an entire runner etc by straightening the airpath.

Clear as mud? Hope that might have clarified it somewhat.

 

On your topic of head porting a friend just returned some high dollar LT1 heads to Texas from his stroker setup.....only ran it a couple hours....they ported so much at least one wall was paper thin and as soon as it warmed up/pressurized it blew out

 

He was pissed! Had already waited months as IRS (internet racers supply) had led him on and sublet his heads to a shop without passing on the timeline....but I'm babbling now.....just glad I'm polishing and not porting per se!

[Kevin Shasteen]

Yea, I was previously thinking "Cross Sectionally"; its amazing-We all speak English & yet the words chosen between us continues to be misunderstood.

 

Its obvious now that you are not planning on removing 25% of the thickness; but (just to be anal retentive here) any removal of metal will increase the cross sectional volume of the port....even if it is only 1-2mm here & there/you've still increased the cross sectional port volume (this is the principle of porting); maiking the turns w/in the ports more efficient. Extrude Honing only uses a less abrasive material than a grinding stone-therefore you obtain that "Polished" appearance...but you are still removing metal & that increases the ports volume & its efficiency to flow air. The rules of porting (whatever you want to call it) remain the same....for an intake, cyl.heads or a carb. Anything that has air flowing thru it works on the same metaphore Vizard described in his book w/the air bing a car approaching the turn.

 

It's this principle that effects an engine's powerband; even if you only port/polish in strategic areas-you are effecting the port volume (increasing airflow/decreasing airflow) and its ability to navigate the turns w/in the ports in a specific location; its this process that determines an engine's efficiency at any one RPM.

 

I Appreciate your clearification; when/are you going to do this or were you kinda of just throwing the subject out there for responses & ideas? Let us know how it works if you decicde to do this.

 

I've only read about this process & never actually knew anyone that did it; BLKMGK is the only one I'ver ever ran into that has done this, & now you're comptemplating the polishing the intake. Do you have any documentation on this process making an engine run cooler? I've read Dyno runs after an intake has been Extrude Honed and they only comment on its 5-10 HP gain & never mentioned the temp's being cooler/hotter(?).

 

Kevin,

(Yea,Still an Inliner)

 

[ May 09, 2001: Message edited by: Kevin Shasteen ]

[BLKMGK]

Actually, if you've ever met anyone driving an SVT Contour you've met someone with an Extrude intake. Several Porsche have had this done as a production process I believe, and there may be other OEM cars out there that I'm unaware of.

 

Someone stated above the racecar on a track theory of air moving in an intake passage. Now, imagine that's abrasive goo! Anything in it's "way" gets abraded - to the point that they must put "shields" on things like valve stem seats where the valve enters the port! This is good, it really does abrade more in the restrictive areas than in the less restrictive areas. It's not so much the amount of metal that Extrude removes that's so good, it's where it removes it. What is also often missed is it's ability to even out flow - the Ford intake is way uneven but after Extrude it's pretty close

 

Honestly, this is the best way to port IMO and if I were to do it again I'd have it done on an intake that had already been hand ported. I've not checked into the cost of having it done lately but $200 isn't too bad for an intake IMO, it's work that can't easily be done by a human that's for sure! Closed chamber contorted EFI intakes have to be cut apart and welded otherwise - ick. I once polished a Ford EFI intake that had been ported this way, when I was done we found out that the weld was porous and leaked like a sieve, never again....

[Kevin Shasteen]

A mild Street Porting of a cyl.head can easily cost $300; so porting/Extrude Honing an Intake for $200 is pretty cheap!

 

I think Ross's (correct me if I'm wrong) approach was intended for cooling the temp's down....has anyone ever read/heard any documentation of the effects on engine temp as a result of Extrude Honing the intake?

 

Wouldnt the underhood intakes temps be countered better if the air was routed/vented out someway; as Ross stated earlier a spacer plate between the TB Intake as well as one under the intake (like an Olds Valley Pan) seperating the hot oil from the bottom of the intake will help lower intake manifold temp's.

 

Aren't the actual (Operating Temp's) going to maintain basically the same temp once it reaches operating temp. If the radiated air is not routed away from the engine bay-it will basically create a "Heat Sink" which only gets worse unless routed out of the engine bay area? Correct/yes-no? Just throwing ideas out here!

 

As I see it; the porting aids airflow and wont really aid lowering temp's; while the spacer plates will aid the lowering of the temp's of the intake.

 

Kevin,

(Yea,Still an Inliner)

[Modern Motorsports Ltd]

"its amazing-We all speak English & yet the words chosen between us continues to be misunderstood."

 

Agreed, just b/t you and I, other posters were in sync.

 

"....even if it is only 1-2mm here & there/you've still increased the cross sectional port volume (this is the principle of porting); maiking the turns w/in the ports more efficient."

 

Disagree, porting is far more involved that just enlarging for greater volume, this alone does not make a port more efficient. Maybe you're mixing your terms perhaps. I disagree that this is the 'principle' of porting. Yes it's material removal but not just for enlargening. It's more to do with altering the motion dynamics of the air.

 

"It's this principle that effects an engine's powerband; even if you only port/polish in strategic areas-you are effecting the port volume (increasing airflow/decreasing airflow).."

 

Nope, not as simple as that, simple flow laws don't linearly crossover if you manage to transition from turbulent (rough wall) to smooth wall (possibly laminar). A slightly enlarged port (mine will increase in area lets say ~5%) may flow faster if it's got smooth walls allowing more laminar flow and less turbulent flow, ie. more efficient.

 

"has anyone ever read/heard any documentation of the effects on engine temp as a result of Extrude Honing the intake?"

 

engine temp is what? coolant? as stated in each of my posts it's my incoming air to the cyliners I want to 'heat less' and thus keep it cooler

 

"Wouldnt the underhood intakes temps be countered better if the air was routed/vented out someway.."

 

We always make efforts to minimize underhood temps and certainly more airflow underhood or isolated 'hot air flow' routed away from engine is beneficial. That's one step but in either event the intake is heating from engine contact even though it has some fairly good thermally insulating gaskets b/t it.

 

"If the radiated air is not routed away from the engine bay-it will basically create a "Heat Sink" which only gets worse unless routed out of the engine bay area? Correct/yes-no? Just throwing ideas out here!

As I see it; the porting aids airflow and wont really aid lowering temp's; while the spacer plates will aid the lowering of the temp's of the intake."

 

Sure, if radiated air has no exit it'll continue to heat to it's saturation point given boundary conditions. I'd like to hear how you feel the spacer plate aids temp drops and not the polishing?? Spacer plate will isolate my TB somewhat so that surface the air passes is cooler (same as a carb but less dramatic as I'm not keeping fuel cool as well). Polishing reduces heat radiated to the incoming intake air. This air will NOT heat saturate as it's long gone down the bore and out the exhaust a few hundred degrees hotter as the new airsupply is coming in......this supply can absorb as much heat as I allow it to from air intake system/throttle body/intake manifold/intake valve etc (function of two items, their temperature/heat stored and their 'radiation' ability).....the more I inhibit the ability of these components to radiate heat into the incoming air the more I've enhanced efficiency and maintained a cooler temp of my intake air leaving it a happier/higher density etc etc/yadda yadda

 

Ross C

 

yeah, still typing )