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Looking on line to valves, I find 2.07's no problem.
Cannot find 2.00, closest is 1.995. Same as the W31 head
Did fined 2.00,but them 4A heads from a 403.
More questions. lol
3rd main controls thrust, so it always looks like that. People melt old pistons etc aluminium to fill the heads, plenty of info when searching. Some use zinc.
And forgot any listed CC for heads, MEASURE them. Again, stock 7A are closer to 68cc than the 64cc listed everywhere. Plenty about that too by searching.
If your going to new valves, the machinist can tell if you need guide-work or not. If you need, $$$$.
Okay neat.
I have 7a's, will use them, just doesn't seem like enough for 2.07 intakes.
Them heads are 47 years old. Not a betting man, but I imagine the guides need changing.
Yes seen people using pistons, must work well if keep using aluminium. Can see the aluminium bonding to the iron
Hmm not exactly what i meant, i just meant that dont assume anything, measure. Building using specs thrown wildly around internet may get you to ballbark, or then not. Its almost 50 years old engine, ANYTHING may have happened to it during the decades.
Assuming things have destroyed many engines. I got a hard time lesson after machinery, even they can crap things. No harm thankfully done, since i measured their doings before assemling.
Last edited by Inline; April 10th, 2019 at 11:39 PM.
With the block 0 deck, you will be around 10 to 1 with those 7a heads. Yeah, technically the W31 valves are 1.995", close enough to 2". The W31 sized valves are fine. My current #6 heads have 2.05" intake valves, according to my caliper and the stock 1.56" exhaust valves. Bowls opened with a cutter, new guides, valve job, top of guides machined for positive seals and 62 to 64cc chambers, paid $400 fresh machined. The other set has W31 valves, bowl and port work, filled crossovers, positive seals and milled to 55cc. I plan on polishing and opening the chambers for my 403 stroker build. The 1800 stall is too small, you want 2000 rpm+ for sure.
On the filled heads, they cause a rough idle in cool weather. I ran them for a year on my 350, warm weather is fine. I am not sure what they were filled with but they did a good job.
On the filled heads, they cause a rough idle in cool weather. I ran them for a year on my 350, warm weather is fine. I am not sure what they were filled with but they did a good job.
Where did you find 2.05"? With 2.07, sure dont seem to be room between both valves.
As for material, alot use melted pitons. A thread on here"home porting techniques", seems to work very well. I cant see the aluminium bonding to the heads tho
Its a spring to fall car, so filling risers isn't a problem.
Take this with a grain of salt. I have my heat risers filled amd had my car out so far on many 30 degree days. Its a world aways from what you are building but my car would warm up and idle fine within a minute or 2 with no choke. Just my experience.
or do I need to count the teeth on the crown and pinion?
No need for teeth counting - the number of teeth is stamped into the edge of the ring gear and on the face of the pinion gear. Just divide the larger number by the smaller number and there's the ratio.
Below is a 4.10 ring gear - 10 teeth on the pinion and 41 on the ring
Last edited by Fun71; April 11th, 2019 at 08:27 PM.
Where did you find 2.05"? With 2.07, sure dont seem to be room between both valves.
As for material, alot use melted pitons. A thread on here"home porting techniques", seems to work very well. I cant see the aluminium bonding to the heads tho
Its a spring to fall car, so filling risers isn't a problem.
They may be 2.07", bought them that way. Going by my digital caliper measurement. The exhaust valve measured right around 1.56, so I must be close.
Supposedly the 2.07/1.625" or even 2.07/1.71 valves will fit. There have been some issues with the melting aluminum rattling. Whoever did my set did a good job, rock solid. Some have also used high temp epoxy with success.
Not commenting to usefulness of it, just offering alternative. Just block the passage between heads and manifold with a piece of sheet-metal.
It doesn’t do the same thing, y’all don't get it.
Without the crossover filled correctly you have the center 4 cylinders sharing exhaust pulses, not good.
When you fill them, AND weld the dividers you’ve now isolated each pulse, just like a header does. If you’re running manifolds this is a waste of time. But if you’re using headers this is the ONLY way you’ll get the whole benefit of them.
Forget about the heat aspect, just use an electric choke. The real benefit comes from isolating the exhaust pulse.
Not much material to take off compared to the old intake tray Some to remove around the chambers, compared to the old gasket.
10/4 Mark.
Well another good day on the block. She had a shower now off in the tub. Started removing valves from my 7a heads, finish the other tomorrow and clean them up. Surprisingly I didnt feel much play in the guides. Call the shop, confirming the block is coming next week
It doesn’t do the same thing, y’all don't get it.
Without the crossover filled correctly you have the center 4 cylinders sharing exhaust pulses, not good.
When you fill them, AND weld the dividers you’ve now isolated each pulse, just like a header does. If you’re running manifolds this is a waste of time. But if you’re using headers this is the ONLY way you’ll get the whole benefit of them.
Forget about the heat aspect, just use an electric choke. The real benefit comes from isolating the exhaust pulse.
Did i say it does the same thing? No i didnt. I offered him an alternative if he/ his boy wants to tinker with the heads, when he asked if its worth the effort.
Last edited by Inline; April 12th, 2019 at 10:46 PM.
Did i say it does the same thing? No i didnt. I offered him an alternative if he/ his boy wants to tinker with the heads, when he asked if its worth the effort.
But you didn’t explain it either.
People will assume if they don’t know, that’s why I believe it helps to explain it from the start. If nothing else it reduces the amount of redundant posts.
Mark, is there a flow gain on a bench or is it more of a dyno thing with filled crossovers? It basically makes the cold idle rougher but if ran from May to September, you will hardly notice. I run my cars on the road as soon as the snow leaves and comes back. This means some -10C cold starts in the morning. I am planning on going back to filled heads or Procomp heads for the 403 stroker. I am not a truck person, only one in Western Canada and these cars rot away with winter driving and heat is marginal. I need to get a second Challenger GT and a hidden hitch for a trailer, utility and drive my Dakota off a cliff.
It’s an exhaust scavenging thing. It would be difficult to do a before and after flow test when you have an open cavity in the middle.
Plus imo it sounds crisper when they’re filled and welded. I did mine first without them done, then about two years later with them done. Noticeable difference.
Understood. I agree, it does change the exhaust note. The video I posted of my G body did have filled heads and sounded amazing, it probably did sound better vs unfilled heads. Of course you can also hear the cold stumble which was also a symptom of the filled heads. Maybe some tuning or adjusting the choke pull off would remove it or it may not.
Not much material to take off compared to the old intake tray Some to remove around the chambers, compared to the old gasket.
10/4 Mark.
Well another good day on the block. She had a shower now off in the tub. Started removing valves from my 7a heads, finish the other tomorrow and clean them up. Surprisingly I didnt feel much play in the guides. Call the shop, confirming the block is coming next week
Notice how much bigger the crossover is on the #8 heads. It is the reason for the two different Turkey trays. A mute point if the heads are filled.
Before the block went for a soak 1st hours of cleaning 2nd hour of cleaning 3rd hour of cleaning 4th hour of cleaning 24 hours later from cleaning
After 24 hours of soaking, took her to the car wash and sprayed the block. Turned out well.
Soak again till tonight and,dry it up and oil the block to prevent flash rust. Install the crank and pistons, ship her to Winnipeg Monday/Tuesday
Okay so went onto summit, used their calculator.
At 60mph with about 25 inch height of rubber
This what I come up with
2.73=2200RPM
3.08=2483RPM
3.23=2604RPM
3.42=2757RPM
3.73=3007RPM
If this is the case, I am leaning to 3.23 in the car
I installed a 3.23 posi in the 80 Cutlass I had 28 years ago (ouch) and going from the 2.28 open that was in it...what a difference. I drove it every day, all over the place. Loved it.
I installed a 3.23 posi in the 80 Cutlass I had 28 years ago (ouch) and going from the 2.28 open that was in it...what a difference. I drove it every day, all over the place. Loved it.
Okay sweet, thanks.
lol on the ouch, here is 1 for you.
As we were hauling the olds home, looking at the car and thinking "dam she looks good for being 30 years old"
Then got me thinking of my 77 cutlass I have to restore, which is 42/43.
Wait a minute, its 40 years old!!!
Time fly's when you're having fun!!!!
Okay sweet, thanks.
lol on the ouch, here is 1 for you.
As we were hauling the olds home, looking at the car and thinking "dam she looks good for being 30 years old"
Then got me thinking of my 77 cutlass I have to restore, which is 42/43.
Wait a minute, its 40 years old!!!
Time fly's when you're having fun!!!!
Oh I know. My 2004 S10 that I bought in 2006 is 15 years old. How did THAT happen?
Many go with a 3 23 gear with a 3 spd. Also a taller tire like the 225/70R14 is a good idea to lower rpm a little more, if you are keeping the factory rims. Yes, both gears need changed. On thing I did was measure pinion depth and used a solid pinion spacer. Also either a Trutrac posi or at least Yukon spider gears if you leave it open. The factory spider gears are soft and explode, mine did. A girdle cover also helps that spindly rear.
The "crown" is called ring gear. Ring and pinion gears are installed as a set. Make sure you have the correct carrier to go from 2.73 to 3.23. And the correct carrier if you go to 3.42.
Last edited by OLDSter Ralph; April 13th, 2019 at 10:15 PM.
Reason: edit
Another good day on the block.
Finished its bath and shower, sprayed it with fluid film to prevent flash rust. Crank, rods and pistons all back in and ready to send to the shop.
Heads soaking tonight, hope to be ready for magnafluxing Monday/Tuesday
The "crown" is called ring gear. Ring and pinion gears are installed as a set. Make sure you have the correct carrier to go from 2.73 to 3.23. And the correct carrier if you go to 3.42.
The posi comes out with the ring gear. The 7.5" carrier split is 3.08 and down, 2 series and 3.23 and up, you need a 3 series posi. Also you have 26 spline axles, the 28 spline axles are an upgrade if the drag strip are part of the future plans.
April 10th, 2019, 10:43 PM
