grinding on the stealths

[70RR2GO]

i'm too cheap to pay for the cnc porting even knowing that it would be more precise. it's crazy how far the ports are off (mostly the exhaust). the edelbrock six pack is pretty bad also. this is the beginning stage and I will be pulling them completely apart so I can do the complete port. also the combustion chambers need some work as mine vary from 80cc's to 83cc's.

 

[GTX MATT]

I had 78-81 CC on mine, roughly the same variation

 

[Moparmatt72]

I did the same thing on my stealths just gasket matched and blended. Plus opened my intake, did it all at home with sanding bits.

 

[sam65]

I would focus more on the intake side than the exhaust.

 

[Moparmatt72]

I've actaully heard the opossite of that, but hey everyone has their own technique, Ive also hears that on the intake side ypu.focus more on the roof of the port and the sides then the floor as well

 

[dvw]

I've actaully heard the opossite of that, but hey everyone has their own technique, Ive also hears that on the intake side ypu.focus more on the roof of the port and the sides then the floor as well

The openings mean squat. Spend time in the bowls. If you don't understand that,STOP. Leave them alone before they're worse than when the started.
I've run a Max Wedge intake on stock 906 ports and gone 11.60. I strongly suggest you start here. Good info.
http://www.amazon.com/David-Vizards-Cylinder-Heads-Design/dp/1934709646

 

[70RR2GO]

thanks for the advice and heads up. I will be giveing the intakes some tlc also. I've been doing my own stuff for years with fair success. thanks again. I've got a friend that flowed the last set I did coaching me also.

 

[SwedCharger67]

...I strongly suggest you start here. Good info.
http://www.amazon.com/David-Vizards-Cylinder-Heads-Design/dp/1934709646

It would be nice to find a good book about porting...but reading the reviews I get the impression that this book doesn't seem to be it???

 

[Herr_Poopschitz]

It would be nice to find a good book about porting...but reading the reviews I get the impression that this book doesn't seem to be it???

It's a decent starting point.

If you have a couple of days, go through this thread...
http://www.yellowbullet.com/forum/showthread.php?t=129971

Pay attention to the details, and imagine how/why certain things were done.

Roof, guide boss, bowl, etc...it's all important.

Going to provide us w/ before and after flow numbers?

Going to be starting a set of Vic's soon myself...

 

[Moparmatt72]

The openings mean squat. Spend time in the bowls. If you don't understand that,STOP. Leave them alone before they're worse than when the started.
I've run a Max Wedge intake on stock 906 ports and gone 11.60. I strongly suggest you start here. Good info.
http://www.amazon.com/David-Vizards-Cylinder-Heads-Design/dp/1934709646

I agree about the bowls along with a good valve job but with out proper alignment of the ports you won't get get good flow characteristics. Everything would be hitting a shelf so to speak. To me every bit helps there are a few more critial areas that need more work then otheres like un shrouding of the valves.

 

[451Mopar]

Before you put them back together, mock them up on the block with the rockers and check for pushrod clearance. You may have to do some grinding there too. I am using 5/16"x0.120" pushrods from SmithBrothers on my engine with the stealth heads.

 

[Budnicks]

knowledge is the key, cause & effects

It would be nice to find a good book about porting...but reading the reviews I get the impression that this book doesn't seem to be it???

:iamwithstupid: a few good books not just about heads thou... some are old, some are not the best, but a mix of theories & tech. data, it never hurts to know cause & effect, especially on a race engine, where you are trying to get the best bang for the buck... also engines Mopar Performance Engines 9th edition #P5249704, has some good ol' easy tricks & tried & true combos... every book has something to offer

 

[dvw]

It would be nice to find a good book about porting...but reading the reviews I get the impression that this book doesn't seem to be it???

I agree this book doesn't tell it all. But the ideas discussed are valid. My point is port matching and thinking that will create power is mainly a waste of time. The bowl , short side, and valve job is where the biggest gains are. With out a flow bench and air speed measurement of various areas of the port you better have a good idea of what you're looking at.
Doug

 

[451Mopar]

I gasket matched and did some bowl cleanup, then just blended it in with a cartridge roll, and also lightly polished the chamber. I then had my machinist do a multi-angle valve job and flow a random port just to get some numbers.
.100" 82
.200" 157
.300" 221
.400" 260
.500" 278
.600" 283
.700" 289
.800" 289

 

[Herr_Poopschitz]

Get the heads taken apart? Any more progress pics?

 

[70RR2GO]

hey pooper, i'm waiting on a couple of hi helix grinding bits. i'll have four days when thanksgiving day comes and should have my grinding done. I'll post then. thanks.

 

[bobtile]

Before you put them back together, mock them up on the block with the rockers and check for pushrod clearance. You may have to do some grinding there too. I am using 5/16"x0.120" pushrods from SmithBrothers on my engine with the stealth heads.

I agree. I had a "professional" install my stealth heads with hughes roller rockers in the spring because I was too busy with work and didn't want to tie up my car. I picked the car up about three weeks later and noticed a racket from under the hood. I said something wasn't right and he told me those rockers make a lot of noise. Drove the car to one of the cruise nights around here and back to the house and parked the car. The next day, I took off the valve covers and found two broken intake pushrods and the remaining intakes bent slightly. He never checked the pushrod clearance. I bought new pushrods, clearanced the tunnels and voila', the rockers weren't so noisey anymore. While I was in there, I threw in a roller cam and lifters just to be safe. Sorry, just venting a little I guess.

 

[Herr_Poopschitz]

Update?

 

[70RR2GO]

I've made big progress and taken them to the machine shop for the hi-perf valve job and surface for the desired compression. I also I'm paying him to flow just one intake and exhaust port to see how I fared. i'll post the results when I get them back. here's a couple of progress picts.

 

[robinsonwr]

70RR2GO,
What gasket part numbers did you use for gasket matching? Really nice job by the way.