First valve job with stones

General engine tech -- Drag Racing to Circle Track

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mag2555
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Re: First valve job with stones

Post by mag2555 »

My way of deciding if steep angle seats and there related flow changes will help performance in a race motor running over .500” lift is to perform a flow test such that once you get to .200” lift you test in ,050” steps for both intake and exh.

In fact even better yet if you don’t mind paying near 100% more for a flow test, then test in steps of .025”.

If your running good race headers then add 3% more flow to the exh numbers above .350” lift.

Next average out those intake and exh numbers and divide the averaged intake numbers into the exh numbers.

If these results pick up the average flow as compared to a similar test done before the valve job, then there’s a good chance the change was worth while, and assuming the intake manifold can pass the additional flow mass,
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
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Re: First valve job with stones

Post by ClassAct »

I do a 50 degree seat on anything I can get the 50 on the valve. I couldn’t care less about what the flow bench says. It’s all about the shape. Lift and RPM doesn’t matter. I don’t hear the lift rule guys clamoring for a 30 degree seat. I don’t know anyone who would consider a 30 degree seat under .500 lift where it really shines. That’s because it’s all about the SHAPE.
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Re: First valve job with stones

Post by zums »

steve cowan wrote: Sat May 08, 2021 3:47 pm Update-
Finally got to the track yesterday after a couple of false starts.
Car weighs 3650 with me
11.25:1 comp 383 010 block
Dart cast iron 165cc heads out to 182cc,1.94" - 1.5" valves
Flow 266 - 228 . 50 deg seat intake and exhaust.
Port matched Vic jnr,a bit of plenum work but more to be done.1" tapered spacer and shear plate.950hp carb
Howard's shelf solid roller
241-251 @ 0.050"
1.6 - 1.5 rockers.600"-570" lift
108 lsa in at 104.
1 5/8" tri-y headers
Testing with 30% MS 109/ pump
Turbo 400 with 8"5600 converter
9" rear gear 4.1:1 255/60/15 radials.
20210508_170042.jpg
Sampled weather-
82F,29.73",56%H,2344DA,91GOW,0.614VP,64.6DP,1.053CF.
20210508_183134.jpg
79F,29.77",59%H,2087DA,87GOW,0.586VP,63.3DP,1.046CF.
First pass is with 30deg timing,shift points 6500 1st ,7000 2nd.AFR reading 11.7 plugs show a bit rich.
2nd pass 34 deg timing, dropped fuel pressure to 5psi from 5 3/4psi,shift points 6000 - 6800 and finish line 6500rpm
AFR shows 12.6 .
I am pretty happy with results considering how basic the engine is and my skill level as a engine guy,plenty of things to try,spacers. Different headers and exhaust, more intake manifold porting, different fuel ratios,go to 4.5 rear gear,different drag radials etc
Any comments welcome.
Hi Steve, not bad for the weight, its a balancing act with a heavy car, i think more lift can help you, maybe 1 3/4 tube and raise the stall if your after et, take the lash down to .010 in .013 ex to see if it responds for starters, your a little rpm limited with 2.07 avg csa, looks like you do clean work, nice job
Tom
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Re: First valve job with stones

Post by BCjohnny »

Nice work Steve

Even with 'unfashionable' equipment, with an amount of care and thought the right person can achieve good results, which is ironically part of the 'problem'

Otherwise, as regards equipment to spin the stones, I don't always use the original 'grinder' ..... if you fashion or buy a suitable (6mm / 0.250") drive stub online it can be done with a normal straight electric die grinder, adjustable speed

Feels more natural on smaller stuff where, say, the original Sioux grinder feels a bit cumbersome

Just do your homework on safe stone speed relative to diameter first
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Re: First valve job with stones

Post by mag2555 »

It’s about the most flow efficiency in the lift range that the valve averages it’s most open time residing in!
If this where not true then there would be no benefits to 3 or 4 valve heads, end of story !!
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
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Re: First valve job with stones

Post by vortecpro »

Nice work!
Racing a NA NHRA stocker should be mandatory before any posting.
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Re: First valve job with stones

Post by jed »

I guess I'm a little out of touch with seat grinding equipment. You stated you use "live pilot and adjustable clutch stone holder"
I have not heard of using eather when grinding seats. I'm only familiar with Souix and Kwik Way. can you reference manufactures of the the pilots and stone holder, also you show a air driver and a Milwaukee cordless driver.
Which one do you most use and prefer. I'm very interested in your equipment and manifactures and where to purchase them.
Good job on your project very impressive.
you can PM me if you wish I have more questions that others may not be interested in.
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Re: First valve job with stones

Post by steve cowan »

mag2555 wrote: Sun May 09, 2021 7:47 am It’s about the most flow efficiency in the lift range that the valve averages it’s most open time residing in!
If this where not true then there would be no benefits to 3 or 4 valve heads, end of story !!
Mag,
I respect your opinion but how I look at is-
Min CSA and avg CSA through intake and intake port will set peak hp in my opinion
This engine of mine would not peak at 6500 more like 6000rpm being just over 2" avg CSA on intake port and manifold runner is bigger in avg CSA.
For this cubic inch at peak piston demand probably requires 300cfm give or take,this intake manifold has approx 6% flow loss bolted to head on the bench hence my earlier post of 300cfm @45" depression.
How much depression does the piston pull on the intake at peak demand?? At a guess more than 45" ??
At 400" valve lift this port flows 90% max flow and gains are very little after that to 700" and I would say its because the area is not there to flow more.this head has pretty good cfm/in2 at the throat,valve and the MIN CSA the pinch,these are what I work on.
I don't look at in/exh ratio - with the exhaust port in my opinion you are governed by the area of the header flange and throat /valve % you want to use for the application,the CSA falls in between the 2 and flow # are what they are.i did not aim for 228cfm on the exhaust port that's just where they are,we have discussed turbulence before so not going back over that.
Just for information this exact same combination lat year ran a best of 11.71 @113.80mph with a 500" lift SFT 235 - 242 @ 0.050" 106-106.
10.6:1 comp
As cast vic jnr
Heads flowed 260 - 177 they were 178cc.
As I said I am happy with the gains first time out,there is a chance that I have no clue what I am doing but happy to learn along the way :D
steve c
"Pretty don't make power"
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Re: First valve job with stones

Post by steve cowan »

jed wrote: Sun May 09, 2021 2:11 pm I guess I'm a little out of touch with seat grinding equipment. You stated you use "live pilot and adjustable clutch stone holder"
I have not heard of using eather when grinding seats. I'm only familiar with Souix and Kwik Way. can you reference manufactures of the the pilots and stone holder, also you show a air driver and a Milwaukee cordless driver.
Which one do you most use and prefer. I'm very interested in your equipment and manifactures and where to purchase them.
Good job on your project very impressive.
you can PM me if you wish I have more questions that others may not be interested in.
Jed,
I will send you a PM next day or so
steve c
"Pretty don't make power"
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Re: First valve job with stones

Post by F-BIRD'88 »

Good job good result. You may have been running into a bit of a headwind...
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Re: First valve job with stones

Post by CGT »

steve cowan wrote: Mon May 10, 2021 5:15 am I don't look at in/exh ratio - with the exhaust port in my opinion you are governed by the area of the header flange and throat /valve % you want to use for the application,the CSA falls in between the 2 and flow # are what they are.i did not aim for 228cfm on the exhaust port that's just where they are,we have discussed turbulence before so not going back over that.
Just for information this exact same combination lat year ran a best of 11.71 @113.80mph with a 500" lift SFT 235 - 242 @ 0.050" 106-106.
So you picked up 50hp give or take. Nice. I could see the new cam being worth 25ishhp.....so the head work had to be worth around that much as well. What was the DA?
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Re: First valve job with stones

Post by Hrdlx62 »

steve cowan wrote: Mon May 10, 2021 5:16 am
jed wrote: Sun May 09, 2021 2:11 pm I guess I'm a little out of touch with seat grinding equipment. You stated you use "live pilot and adjustable clutch stone holder"
I have not heard of using eather when grinding seats. I'm only familiar with Souix and Kwik Way. can you reference manufactures of the the pilots and stone holder, also you show a air driver and a Milwaukee cordless driver.
Which one do you most use and prefer. I'm very interested in your equipment and manifactures and where to purchase them.
Good job on your project very impressive.
you can PM me if you wish I have more questions that others may not be interested in.
Jed,
I will send you a PM next day or so
That's a new one to me also. Would really like a little info on that setup
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Re: First valve job with stones

Post by steve cowan »

CGT wrote: Mon May 10, 2021 10:03 am
steve cowan wrote: Mon May 10, 2021 5:15 am I don't look at in/exh ratio - with the exhaust port in my opinion you are governed by the area of the header flange and throat /valve % you want to use for the application,the CSA falls in between the 2 and flow # are what they are.i did not aim for 228cfm on the exhaust port that's just where they are,we have discussed turbulence before so not going back over that.
Just for information this exact same combination lat year ran a best of 11.71 @113.80mph with a 500" lift SFT 235 - 242 @ 0.050" 106-106.
So you picked up 50hp give or take. Nice. I could see the new cam being worth 25ishhp.....so the head work had to be worth around that much as well. What was the DA?
1 st pass 2344DA
2nd pass 2047DA
full weather sample on bottom first page :D
steve c
"Pretty don't make power"
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Re: First valve job with stones

Post by CGT »

steve cowan wrote: Mon May 10, 2021 1:17 pm 1 st pass 2344DA
2nd pass 2047DA
full weather sample on bottom first page
Oh I see that now :lol: . Your previous bests....were they in similar weather?
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Re: First valve job with stones

Post by steve cowan »

CGT wrote: Mon May 10, 2021 2:35 pm
steve cowan wrote: Mon May 10, 2021 1:17 pm 1 st pass 2344DA
2nd pass 2047DA
full weather sample on bottom first page
Oh I see that now :lol: . Your previous bests....were they in similar weather?
Very similar weather Chad,our racing season is march to September, to hot and humid for me otherwise
Tom suggested backing the cam up a couple of degrees- should mph a couple more maybe :D
steve c
"Pretty don't make power"
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