geckonz08

Haven`t seen any previous pics on this plate so here we are
Not sure how it will go but am sure it will do no harm.

Rickman48

Looks good - only thing I'd do different is find some copper exhaust gaskets - in my experience, cardboard doesn't last, and it'd be a real PIA to replace them!!

TripDeuces

That plate is designed to straighten the abrupt transition that the port floor makes as it exits the head. If I remember right it's worth about 15 cfm. If you look at an Edelbrock head you can see that the port is smaller as they filled in the floor to do the same thing. You're right, it shouldn't hurt anything.

geckonz08

Rickman--yes I have 2 cardboard and 2 copper --might try n get 2 more copper .

Tripdeuces
Mmm will be interesting ."Someone " said they did nothing for their engine ,others believe to the contrary.I think fitment is all important(time will tell) .I cut the 'fins?' off at 1 inch plus/minus and slightly over bent them maybe 1/32 .When compressed they snug in tightly to the floor. There is maybe 1/2 hr of die grinder/snips or whatever your poison is to cut n fit the 'fins'

mike

Texas Jim

I looked up that "exhaust plate" last night in the "Dick Miller" catalog. It does say that it adds 15cfm and can be used w/ headers or manifolds. I don't know how someone could tell if it gave up that 15cfm or not w/o a flow test, one w/ and one w/o. That's interesting, never saw that before.

507OLDS

If he would say that they do NOT add 15cfm,would they still sell?No.
I understand the idea behind them.I would just fill the floor of the exhaust ports.With the port plates,or the filled ports,you need to make a different header primary opening,as you now have a cliff for all of it to fall off of.Either make a square opening to match the new port opening,or possible do more shaping to the port,and make a D-shaped port,and match the headerflange/primary to that,then run a step-header design.
You could correct some of what you done by raising the roof of the exhaust port opening,and just slotting the header flange holes,and moving that up.

geckonz08

thankyou Brian.Then how about a plate over the length of each flange stub -starting in the same horizontal position as DM plate and tapering down over the flange stub length (2" ? ).Could attach it to the DM plate ?--sort of L shaped mirror image . Would that be effective ? Or I could weld the same to the stub with a taper and just butt this to the Dm plate ?
Brian, I can`t lift the ports really much more as the roof is already pretty much straight .It may not show as the top gaskets are just placed there but the holes on copper gasket underneath have been altered maybe 1/8"?
I guess it`s not now how far in the sh&* I am but how I extricate myself from it .
Mike

507OLDS

It's kinda hard to see from the pictures,but are your exhaust ports in your heads ported,and the roofs already raised?
As for the copper gaskets,there are a few different brands & shapes,but there are a few,like the ones I use,that I actually installed them upside-down.I just snipped the center bolt eyelet.By doing this,the gasket lined up much better with my ported iron heads,with the rasied roofs.

geckonz08

Brian , a couple of pics --not brilliant but

1. showing where ports were lifted to--black marker line--this was during the process . Ports have also been polished .

2. the copper gasket

tx mike

507OLDS

OK. My ports are slightly higher.I do know that before I started installing the gaskets upside-down,I was filing some of the exccess material away that was in the path of the port opening,but I didn't need to get anywhere near the sealing bead.I'll try & send some pictures,but it might be a few days.Kinda hard to explain.

geckonz08

Brian, I know exactly what u mean .I will have to do a little of that .Will wait till the flange is bolted down.

I have also taken note of what you said re the 'drop off ' from the DM plate to the ex pipe . It`s like going into a sports or hardware dept --once I start I can`t stop , so I have welded some little tongues that protrude into the ex pipe . That`s it , I am done .This is , all said-n-done a street driven car --lotsa other things I could do to it if I wish to continue being semi-****. Mind I am happy how they turned out !!

507OLDS

What car is all of this going into?

geckonz08

86 cadillac brougham --to replace the 307 olds motor. On a cad site some 2yrs back , the suggestion was made that instead of using a 472 or 500 that I should be looking at an olds 425 or 455. So, the engine is going to the 425 toro-66 . I have now purchased the majority of parts and have found an engine builder who is well aware this is an olds engine not a chevy.
The specs are as follows
reground crank, clevite bearings
rebored to 30 thou using hi comp cast pistons
zero decked and retaining 10 to 10.25 comp ratio
comp cams roller rockers kit
erson cam 284/295 228/235 110 509/523 (mark`s)
O4B intake with wee bit of grinding to fit the HEI
Recon qjet
tri y headers 2" > 2.5" > 3" > x pipe
beefed 200 4r
3.23 posi
Thats the main stuff with lots of small items such as enlarged oil drain back holes in heads, welded central port divider, Al filled x over , removal of hump in toro pan etc

mike

Rickman48

Sounds fun, in a Caddy! Whatcha doing for gears??
A '79 won all the marbles a few years back, in a 'real street car' test one of the mags put on, but I think he had a 500 in it!
Someone also said the Caddy 500 is close to SBC in weight, due to the thin-wall casting design - just some info -

geckonz08

200 4r ,3.23 posi --that what u mean Rick ?

geckonz08

a local chap has offered to get me some flow rates on these heads ( cheap cos they are different --they are around here.)I said I wasn`t that interested .Then I thought well maybe someone here is interested in some flow numbers --all adds to the info library . Anyone want the numbers I will drop the heads off ?. My Small monetary payment/contribution for all the info I have gleaned from here.

cutlassefi

Sure, why not?

J-(Chicago)

I'd enjoy seeing the numbers.
Looks like you're going to be having some fun.

Texas Jim

If at all possible, I'd love to see the flow numbers w/ and w/o the "Dick Miller Exhaust Plates." Then we can say f/sure what those exhaust plates do or don't do f/ performance.
I think that would be what most interests us about the head work you've done. It's too bad that you didn't have numbers from before and after all the machine/hand work you've done on the heads. In any event, sounds like you have the "bull by the horns." Good Luck and thanks in advance.

geckonz08

Yes jim , I imagine The DM plates flow numbers are which interest you . Everything else seems to have been done a zillion times and zillion n 1 since I have just "copied" lol. And those DM plate numbera are those I will be looking for .
Speaking of BULLS --short digression --ran into a wild one when deer hunting recently. Heard a noise but the dog wasn`t showing interest. Must have been 20 yds from the bull when I saw him in the fairly dense bush.Tell you I backed off real slow,with the rifle safety off , and my rect*^ doing dime to a dollar @ 1000 rpm .
mike

geckonz08

haven`t forgotten
ok got my new valves from valve technologies--I was happy with what John had supplied and what I owned but ... .... at least the builder is fussy.
So, am getting valve job soon followed by flow test (for better or for worse)

BTW--jIM AT VALVE TECHNOLOGIES IS ONE HELPFUL GUY --VERY