Progress... 400/451 coming together

[70bigblockdodge]

Wow look at the material to remove intake windows, you can't tell me that doesn't affect flow. How is the other side gasket isn't hanging over is it? I usually profile the guide down/ smooth down but don't cut down the guide itself where the stem comes out, be careful with floor of exhaust port smooth it out but don't remove anymore its okay if it doesn't match. Looks good keep us up to date

 

[70bigblockdodge]

Looks like good therapy I might have to get back on the set of 516 castings I have

 

[flyinbrick68]

ive got a set of 516 a buddy already started porting got them for free so after I get the 346's done for the car if I think I haven't messed up to bad profiling the guides ect ill work on a set for the truck if I have the funds. It'll sure help the smogger rv 440 in it.

 

[70bigblockdodge]

Yeah they are good for a compression increase. I don't think you can screw them up if you stay on the conservitive side because they would run if you did nothing, as long as the sharp edges are blended in the direction of the airflow.

 

[flyinbrick68]

getting better

 

[commando1]

I never did a port n polish.
Too chicken.
Good for you!

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[flyinbrick68]

well yeah if I mess them up I have a set of 516's and a set of 452's in the garage and a spare rebuildable 400. I'm going to have to start selling off motors though to get some space. If all else fails and something goes wrong with I guess I've got a spare running 383 out of the 70 d100 for the car.

 

[Stormer]

Love it. You aint scared.

 

[flyinbrick68]

I'm trying, always good to try new things! And hey I'm a positive person ya never know could always be used later as a tech article. How not to port cylinder heads haha! bout 3/4 of the way done with one head. One more cylinder then sanding rolls and maybe deshroud the valves and possbly clean up the casting outside of the valves.

 

[thrashingcows]

I'm trying, always good to try new things! And hey I'm a positive person ya never know could always be used later as a tech article. How not to port cylinder heads haha! bout 3/4 of the way done with one head. One more cylinder then sanding rolls and maybe deshroud the valves and possbly clean up the casting outside of the valves.

I follow your outlook as well....I had never rebuilt a transfer case before...learned and did it. Same thing with my cummins 5 speed...learned and did it too! I really enjoy trying new things...and hey why pay someone else to screw it up...I can do that for free....;) :tongueflap:

 

[70bigblockdodge]

Thats how I ended up doing these stupid gm transmissions. Cooler line rotted dumped fluid on highway burned up 3-4 clutch pack which I learned calling around for prices, watched a couple of youtube videos and only had to go see the local trans guy once to bail me out with sealing rings ( messed one up trying to put it on, more youtube). I figure I have seen enough dummies that manage to keep jobs at these shops so I should be able to do it. LOL f.b. are you using the stock valves or one. piece stainless, the stock valves need backcut. You should go with one piece stainless its good insurance.

 

[70bigblockdodge]

hey why pay someone else to screw it up...I can do that for free....;) :tongueflap:

This must be common with truck drivers I agree!!! Like your new signature, I can relate more than mushy bananas lol.

 

[flyinbrick68]

I'm using milodon stainless 2.08 1.81 valves theyre back cut with a 30 degree angle i think.

 

[70bigblockdodge]

Thats good no lip.

 

[70bigblockdodge]

There is a thread on fabo" 318 head porting for the average joe" I would post link but I don't know how

 

[flyinbrick68]

Pistons arrived today in the mail finally! I went with the Icon 837's the machinist seems to think I shouldn't go over 9.4:1 Look to nice so well see! I think i'll set them for a bit higher perhaps at between 9:6.1 and 9:8.l due to my elevation. Wish I had a scale to weight them to see how much they weigh I think think the info is off on the website for keith black.

 

[coronet66jj]

I just started following your engine project. Is it a 400 block with a cut down 440 crank? And if I understand this right this design will yield a larger bore and require a custom piston and aftermarket rods. the benefit of the dish piston in the large bore is better flow?. Probably a design for big torque in a heavy street driven car? run on pump gas? I like it! plenty of 400 blocks around to use , and open chamber heads too! I am interested in how well this works out for you.

 

[flyinbrick68]

I went w a forged piston that's dished so i could keep the compression down and run pump gas. 9.5:1 to 9.7:1 is as high as i want to go. Its basically an oprimized 440 with a bigger bore of the 400. Stronger and lighter than factory parts. Im shooting for a ton of low end torque and hoping for a 1to 1 motor. 450 hp 450 ft. lbs. torque should be achievable. Im using open chamber 346 heads still working on porting them.

 

[moper]

You're doing well, but a couple notes...
You are wearing a dust mask or respirator - right?
On the intake ports - You need to concentrate on the port entry more - the main flow is along the roof and "inside" curve so make the corner radius cleaner to follow the gasket shape. Shape differences there can have a large affect. The port floor is better left untouched and lumpy. In the bowls with the templates - IIRC they are made for 2.08 valves. Follow the templates and leave the bowl smaller. Don't "hog it out". It will flow better properly shaped rather than larger. When you have the valve job done make sure the shop uses cutters for the seat angles, and have them to a 5 angle - that includes a throat cut and an unshrouding cut in the chamber. Don't polish it beyond the rough grit sanding rolls, and leave the floor untouched until the area where the approach to the short turn starts.
On the exhaust - Do not go to gasket opening size at port exit. Raise the roof to the gasket hieght, blend the lump (I'd be careful - there's coolant right there too) on the roof, and keep the finished port about .100" smaller than the gasket size. Blend that back to the bowl area and again - watch your corners. The exh port can be fully polished.

 

[flyinbrick68]

Thank you very much! Thats the kind of advise i was needing! Yup i'm using a dust mask! Just porting a bit at a time when i do have the time and the weathers nice.