a 655 after porting

[The Pope]

This is a head I ported for ohnotagain here. I don't do much porting, I just don't have time, but I spit out about 3 heads a year lol.

This is a 655. The 655 is interesting on the floor. You look at photos that Mopar / Directconnection (not steve) posted in books of the floor and you see big peaks and valleys, sharp. I do actually cut the floor flat. But your talking a tiny bump at the gasket and a larger bump at the seat. I am going to test the bump at the seat and without it, this head is without it. Also the inside turn stock is a short 90 degree edge, pretty bad. When you go big valve, which the head I believe was designed for, the floor gets thicker as you move the seat back. So I added my own inside turn there and reshaped the floor. Then the common V at the guides. There is some port shaping as you widen the port as it hour glass' stock. The exhaust port requires most work at the gasket. Normally I do a whole gasket port window. I am now not porting exhaust manifolds to the gasket on the floor. Just width and hieght. From Shadow / Robs performance I am going for velocity and not worrying about volume on exhaust. So since you drop a big valve from 140 CFM down to 113 with a manifold, no reason for the flow. Just more velocity for more pressure. Except for the TU header which basically flows a big valve..

It has been looking like power is off how much you get into an engine lately. Terry's numbers per PSI were very impressive. But one of these days I want to test a LW intake vs a heavy ported 2 piece on a 655 though. I'm pretty sure you can't completely feed this head right with out doing some fab work like Shadow did with his intake. The LW intake may have the port cross section and length to feed this head right.

I have a big valve 782 and a G head, looking like a Tyler head too to compare too. Even a stock Masi head. So I should have some curves next week I'm thinking to compare this head. It has been said the head doesn't flow at low lifts stock, I do have better low lift numbers with the 655 than a 782. Did I hurt low lift a bit or help it? This looks like Terry's ports and like the way I do V8s which works so I am really wondering how this will fare now with the right valves.

I ran out of 120 grit, so 80 grit then polishing leaves it pretty scotched looking lol But it is smooth to the touch I can tell you... So try not to harp on me for scratches too much lol.















No 655 opinions on bashing the casting, because we've all heard it. Feel free to bash the porting though with good language lol. I'll post 3rd party flow numbers again next week, I haven't checked what day Dick has time. Old man = don't like phones....

[The Pope]

found a couple more from my cam.

[nvysion]

I want this head plzzzzz

How a ported 8V head, like this or your Ghead or swirl head flows vs a stock 16V head ?

Thanks for sharing Rob

[The Pope]

Quote:

Originally Posted by nvysion I want this head plzzzzz How a ported 8V head, like this or your Ghead or swirl head flows vs a stock 16V head ? Thanks for sharing Rob

depends on the 16v, the masi has the lowest intake flow, the T3 and the Neon head really does well.

Interesting info is the Neon oval port opening is exactly the same size as a 655 though lol. Just not nearly the valve area.

Doubt it'll flow as much as a 16v, but with the right intake I don't think you "need" 16v for most cars, even a drag car. I like the head for doing a numbered car, which should stay 8v always. This head should push into 600 HP range, how much do you really need? This will go way past what you can really use on the street, guys like Shadow run HALF the boost on the street they run at the track. This with the rest of the parts would be over doing it at 15 PSI on the street unless your in a mini van lol.

I will know soon what cam is needed, I suspect you'd need to get boostgeeks cam to use it though. In NA form to use the 655 in the 80s they ran a Crane .610" lift cam and the longer valves. I would think the smallest cam to be in it to be the S60 and the next up the R2+. The other heads don't like a much past .500", they flow but not a steep climb in flow. The 655 ramps off stock at .600", so I'm sure it it going to want at least that now. But that's what you get with a big volume port, the need for a big cam. I've seen .645" lift Ford turbo cams......

[The Pope]

BTW, there is almost zero work to make the intake port bigger, floor bumps and a 1/16" off the sides maybe. 95% is the seats, 4% at the guide, 1% runners. Exhaust port is almost the same but you cut a lot at the gasket, it really needs the "match porting" at the gasket. The 655 is the whole gasket stock on the intake, maybe a 1/16" of an inch to remove. Actually makes it tougher to clean up the port and not go way past the gasket lol. When I go a lot on a 782 or G I can measure each out and make my own window basically. If you do that with a 655 your out past the gasket.

[nvysion]

Hi Rob,

What is a 655 head ? From which car do this head come ?
what are the differences between a 782 swirl head (faster combustion), a G head (less CR) and a 655 head ?

What is a LW intake ?

Cindy is selling a ported 16V head for $1200, vs $1400 for a stage 3 782 head.
If this 16V head is flowing more than any 8V head and cost less, what are the advantages of an heavily ported 8V head ?
I have bought a Holset HE351 with an exhaust header, Spearco 1080 fmic and FWD H beam rods and now I'm looking for a head wich would match the parts I have.
So I would like to know your opinion about 8V and 16V.
The 16V head will need cams, sprockets, ..., and would not be compatible with the exhaust header.

Why Shadow and you are racing with a 8V head ? Are you looking to get the best of an 8V head ?
Don't get me wrong, I'm not bashing you, I'm on the contrary admirative of what you are doing but I want to learn and understand.

Thanks
Louis

[glhs727]

My 16v head I'm selling would normally sell for a lot more than $1200... so don' consider that a normal price. Also the 8v head actually take a ton of work just to get it to flow almost as much as 16v. The 16v doesn't need a lot of work to flow even better than it does. Also comparing the two is like comparing apples and oranges.... having said that, unless you are starting with the t-3 lotus motor, trying to put the 16v lotus head on a 8v motor can be done but would be very costly (head, cams, rockers assembly, spockets, serp belt set-up, ps pump, valve covers, intake mani, ex. mani, electronics etc...) so that's why most people with a 8v spend more to make the 8v head flow better becuase it is still cheaper than converting to 16v

[nvysion]

Thanks Cindy
Damn if needed only your 16V head, I would jump on this deal.
Is there a lot of difference in performance between a stage 2 8V head and a stage 3 head ? Same porting with only bigger valves ?

[4Daytonas]

Rob-- How do you get these large pix posted on here? Let me know and I'll show you my 287 ports.

[The Pope]

8v even this head isn't considered best flowing ever, or any other guys 8v ported head. For the money you can't touch the Neon head, 300+ CFM on the intake for $400 in CNC porting from Indy. Then with a Ported Indy intake or another built 16v intake like LW / Lonewolfs to feed it. FWDperformance has sold LW parts over time too, never know what they may have in stock.

Keep in mind if you build any of the 2.2 / 2.5 16v engine it is going to be a lot of money. The T3 needs a lot of money in it and gone through if you buy that engine outright and you need all the wiring. Then the Masi, massive money everywhere. Then the hybrid, custom machine work and pulleys etc. So the 8v isn't that bad of an idea.

Then there is an engine swap. This is the most power per $, adding the PT / SRT 4 2.4 turbo engine into the older car. Hone it and add rods and pistons and a few little HD mods and your ready for big power. You don't "need" head work, intake work, or tons of custom little mods.

So going that route isn't a bad choice for the max power.

Now for the questions.

655, 81-82 Chrysler head. This head uses the full intake gasket port window and requires a custom intake to use it. Even if you don't go ported. This head is basically the same as the G head, even with parts. The difference is the ports, they are a lot bigger. The 782 is more different than any of the other heads.

Lonewolf / LW intake for 8v, pictures I've seen show the intake cut to a 655 port window and they opened the 782 to the port window. So maybe a little bit of porting and it'll work with a 655, or no work at all if they set it up for it.



Many of us old TD folks would rather play with the 8v, I don't think there is a logical reason for many just choice. The other reason for me is I have 2 numbered cars I don't want 16v engine swapped.

For you, your not in the US. Going out and doing a complicated engine swap over there is going to be up hill. I also don't know about the legal issues over there with it. For you buying a ported 8v top end and bolting it all together. Then using a stage 5 computer to tune it is going to be your best choice. But that is because of where you live and in the long run you may not need more. Shadow is already moving to the end of the HE351 with an 8v and with a stage 5 computer. So if you can max the turbo you have basically with 8v there is no serious need for 16v.

I would talk to FWD about filling in the blanks. I would at least have a fully ported 2 piece with plenum on any 8v head with that turbo. Those aren't cheap. So at that cost level the LW intake doesn't look so bad starting from scratch. I port and I own 2 piece intakes and I can make my own plenum, little cheaper that way lol. You you pay for it out right the LW intake combined isn't so ugly in cost. The 655 with big valves should be a little cheaper than the other heads, but only in labor as the head is faster to port. It isn't the MASSIVE work the 782 is.

I like my valve train the best lol, no supprise there. The Beehive thread and the PT thread. Cam has to do with which head, buying something out right the FWDperformance F4 with the D window heads and the TU R2+ for the 655. If you can buy custom a .550" lift version of the F4, same duration, centerline, LSA, etc would be best on the 655. There isn't really a cam made for it anymore. Depending on the flow curve it may need the .610" lift like Crane sold for it with turbo cut lobes, that would also mean longer valves (.1" longer installed) with either off set locks or a .050" spring shim. Then comes the lifter, I know the PT is fine with .551" and 7,000+. But .600"+ lift? People may need mechanical lifters and another .015" lobe for lash.

So like any engine you add a cam made for how the parts work together. In this case the 655 is going to work differently than the other heads because of port volume. The best cam for a ported 782 may not be the best cam for a 655, that is just the reality of it. With a 440 you can't run MP cams with Indy heads like you do with 906 heads, not too different really.

[The Pope]

Quote:

Originally Posted by 4Daytonas Rob-- How do you get these large pix posted on here? Let me know and I'll show you my 287 ports.

I insert them, then if you open the attachment it is full size. If you link to it the system shrinks it. Use the paper clip looking thing

[The Pope]

Quote:

Originally Posted by nvysion Thanks Cindy Damn if needed only your 16V head, I would jump on this deal. Is there a lot of difference in performance between a stage 2 8V head and a stage 3 head ? Same porting with only bigger valves ?

The higher stage head with the big valves requires new seats and then a lot of labor on the seats to cut them to 44mm. That is pretty tough, the ports also get bigger. So when ever you get a big valve head it gets expensive.

I wouldn't do a 655 without the big valves, and I may even do custom larger valves than our current big valves as I'm still not out to the bowls yet... I'll have to see how it works the way it is first. The 655 is easier than a G head to port, some one could copy what I've done pretty easy. Only the 782 has people doing really custom work. Opening a G head to a 655 is just too much work lol. Just buy a 655 and use all the parts from the G and clean it up. If I was building an NA I would consider that method of making a really custom inside turn / floor for high velocity and lower volume and higher engine vac. With boost your just trying to pile compressed air on the intake valve that doesn't decompress when the valve opens... Pressure changes the physics of how flow works, because it changes port density. You add the inside turn to a NA head to increase your high pressure area of flow in the port. You pull air to the side turn so it doesn't bunch up on the ceiling, creating more high pressure area. This is a path down the center of the port that your are trying to get to turn into the port without it "hitting" and disrupting flow. With boost that density is pushing the air to the sides of the port, the whole port window is flowing high desity. So you have a hydraulic friction loss to look at, not maintaining a high density flow path.

With hydraulics friction loss is everything. Because high density is made to run at low speed, not high speed. You add larger line to slow velocity for less friction loss and more total volume. Shadows intake has a much larger cross sectional port than stock. Boost fills the port and moves slower with less friction loss. When the intke valve opens it has more volume to decompress into the cylinder and it is feed as the valve opens. This also means your stacking air, not working off of a cycling air wave like NA.

With friction loss you hit a "max" velocity. Past that your volume gets greatly effected. There is also a lot of work involved with creating more velocity, to speed air through a smaller hole means a lot more drive energy. Granted my engineering I do daily is with different forms than a car. But it is the same physics. Lowering friction loss with an air blower or a fluid pump is massive when it comes to flow. The 655 with the right intake has less friction loss with high density flow. If water ran though a LW intake and my 655 it would really move the volume compared to a stock intake and G head. So you could say I work them to move water better, my opinion is that the physics under boost is closer.

[ohnotagain]

my head looks great rob! im looking forward to getting this engine together and in the car, my engine bay is freshly painted but looks so empty right now,lol.

as far as cams go im just going to have one custom ground to match the application. i found a company that specialises in regrinds , they arent far from rob and he's used them before. Delta Camshaft they charge $125 for a regrind that requires welding the lobes, far far cheaper than a $350 billet cam. it will be a roller cam, along with PT lifters and crane 996 LS springs to complete the valvetrain.

the intake will consist of a welded and ported lower half of a 2 piece and a custom made plenum that will look similar to the LW intake's plenum above.

trans will be a fully built 413 auto with a 3500 stall converter. i will probably add a transbrake to it as well, but no reverse pattern manual valve body, i really like the B&M ratchet style shifters and i would need one anyway for positive reverse lockout per NHRA rules that most tracks go by.

my goal is the quickest street legal 8v shadow. im hoping to push the car into the 9's by the time its all said and done. brian slowe has been there already in his shadow but he runs a pretty wicked hybrid engine-2.2 with neon dohc head. i want to do the same with less. i've shaved as much weight as i can off the car already without going to polycarb windows. all HVAC components have been removed, car will have no interior other than 2 lightweight racing buckets and a small fiberglass dash to hold gauges.

engine management will be MSIII running full sequential injection and coil on plug LS2 coils for ignition, with E85 for fuel. unfortunately due to MSIII using new code the 2.2/2.5 dual hep wheel decoder no longer works so i have to use a 32-1 wheel mounted to the pulley for an ignition trigger. but since i have to do that i've taken it upon myself to design and build a bolt on adapter that fits the 32-1 wheel and a bracket for the VR sensor to the 2.2/2.5 with no modifications. if im sucessfull with that i will be making a kit avaliable to the TD community.


the easies tway to post large pics is to use Image hosting, free photo sharing & video sharing at Photobucket create an account there- its free, upload your pics and it will give you imbed codes under each pic in your album, for either a thumbnail pic, a pic suitable for emails and a full size pic perfect for web forum posting, like this one--



the nice part about that is you dont have to worry about limits to the number of pics you upload to the forum.

btw thats the car this beast is going into. freshly painted inside and out over the summer. its a bit dusty from sitting in the garage but it turned out pretty good for a garage paintjob.

[nvysion]

Thanks Rob,

I have read your posts at least 4 times in order to begin to understand what you have written.
That is one of the best thread I have ever read.
Don't ever think to quit the forum like Shadow has written, you have too much knowledge to share.

Thanks for the advices, I will stay with the 8V.
In Europe you can find 2.4NA engines in the chrysler voyager and PT cruiser.
2.4L Turbo in the PT cruiser GT.

I have never seen seen 655 heads for sale.
I have a 2-piece ported by MPGmike but the LW intake is stunning where can I buy one ?

Last question, do you know a book where I can learn the principles of head porting (not to port my head but to learn) ?
I still have to struggle to understand some of the technical words you are using.

[The Pope]

when you go high lift with a regrind the follower hits the middle of the valve, then goes to the edge and off the edge in the old days. When you go stock the contact point is better but still goes for the side. Then with a larger than stock base circle like a PT and no washers the contact point works the center of the valve stem, with a follow angle at .3" at .5" after.


http://www.pnw-sdac.org/gallery/d/2824-1/scan0001.jpg

http://www.pnw-sdac.org/gallery/d/2827-1/scan0002.jpg

At high RPM there is a lot of load, then you have very short springs and guides in a 8v head. If possible going larger pushes straight down on the valve, going smaller with a regrind is scary. Also, the PTs don't work with a smaller than stock base circle.

I think FWD can get a billet cam blank a lot cheaper, but I'm not sure how big you can get it. Often people just use a slider blank, seams to work fine in a low mileage car for racing. The cam may need to be played with I'm sure, the R2+ is a new cam for $300.

What your going to do with it is what the head is best for. I don't think I'd run one with a little turbo lol.