Are the Afr 185cc heads to big for a stock 302 short block?
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Depends on the cam intake combo. They would be fine on a combo that stays above 4500 most of the time. But for a daily driver with just mild, driveable mods, they are too big.
Bump that 302 to a 347 and now you are talking.
Bump that 302 to a 347 and now you are talking.
Starscream88
New Member
DropTop,
Do the AFR 185's have 2.02 valves stock?
You said you ran them on a stock Block,
Did YOU have any piston to Valve issues?
This is the reason I ask
http://forums.stangnet.com/showthread.php?t=474865
im going to be using Stock Cam, 1.7 RR,
But 2.02 valves,
Was you ok?
Do the AFR 185's have 2.02 valves stock?
You said you ran them on a stock Block,
Did YOU have any piston to Valve issues?
This is the reason I ask
http://forums.stangnet.com/showthread.php?t=474865
im going to be using Stock Cam, 1.7 RR,
But 2.02 valves,
Was you ok?
69Rcode_Mach1
Active Member
They aren't too big for a daily driver windsor though?? Because that is the head that I am looking at. I will be adding cam intake etc.... also. Sorry don't mean to piggyback just curious about spending $1300.
With a stock cam the 2.02 vlv will clear and they are not too big for a stock 302. Go over to Corral.net and do a search for ndpm40, he installed them on a 302 with stock cam and heavily ported stock intake and made more torque and HP from idle up. You won't see much benefit from using them unless you change the intake though. Nothing wrong with big heads if it's cammed right.
here read for yourself:
http://www.corral.net/forums/showthread.php?s=&threadid=483002
here read for yourself:
http://www.corral.net/forums/showthread.php?s=&threadid=483002
88stangmangt
Active Member
even with a stock cammed 302 bottom you still got to notch the hell otta the piston's so unless you plan to pull the lower....................go with 165's those heads are better for more low end torque too...........Starscream88 said:
I was considering the same thing and sent Ed Curtis at FTI an email. He said the 185's would be way too big with a stock cube motor. The 165's would be the better choice. Another thing to consider with those big valves is the 1.7 rr's add .030 to your cam's lift. Most cams are spec'd out with 1.6 ratio. I think you'll definately have to notch the pistons if thats the direction you are going.
Michael Yount
Mustang Master
davs5.0 - peak lift has zero impact on piston to valve clearance; the rocker ratio change in lift you've quoted (which by the way is only an accurate number for a cam with .498 lift at the valve with 1.6's) occurs at peak. Re-read 90Notch's post - p to v clearance occurs during the overlap period - when the intake is just opening, the exhaust is just closing and the piston is passing through tdc at the end of the exhaust stroke/beginning of the intake stroke. At that point, valve lifts are usually somewhere in the .08" range -- which means your rocker ratio change (.08" X 1.7/1.6 = .085") only reduces clearance by about 5 thousandths of an inch -- a non-issue unless you're right on the edge anyway.
It's bigger valve heads, and earlier opening intake events/later closing exhaust events (more duration, more overlap, smaller LSA's) that reduce clearance.
A very strong motor can be put together with either the 165's or the 185's and the stock cam - very reasonable bottom end can be achieved with either. But in my mind, if you've picked a cam which isn't gonna let you rev high enough to take advantage of the greater flow potential of the 185's, why not go with the 165's anyway? All else equal, piston to valve clearance will be greater with the 165's because of the smaller intake valve head, and with the stock cam you're not gonna max out the flow potential of either head. I can't see any benefit to the 185 unless you're contemplating future mods or use on another engine down the road.
I think 90Notch is on the right track here.
It's bigger valve heads, and earlier opening intake events/later closing exhaust events (more duration, more overlap, smaller LSA's) that reduce clearance.
A very strong motor can be put together with either the 165's or the 185's and the stock cam - very reasonable bottom end can be achieved with either. But in my mind, if you've picked a cam which isn't gonna let you rev high enough to take advantage of the greater flow potential of the 185's, why not go with the 165's anyway? All else equal, piston to valve clearance will be greater with the 165's because of the smaller intake valve head, and with the stock cam you're not gonna max out the flow potential of either head. I can't see any benefit to the 185 unless you're contemplating future mods or use on another engine down the road.
I think 90Notch is on the right track here.
Michael Yount
Mustang Master
LOL Davs5.0 -- according to Mr. Alice Cooper, and I quote, "school's Out for the summer"...
Maybe Ed will jump in here and elaborate, but I'm guessing when he says the 185 would be too big, he probably doesn't mean they'd be harmful; just that if you can't take full advantage of them (higher flow rates, higher rpm), then why go with the larger size - it's a wasted resource.
Maybe Ed will jump in here and elaborate, but I'm guessing when he says the 185 would be too big, he probably doesn't mean they'd be harmful; just that if you can't take full advantage of them (higher flow rates, higher rpm), then why go with the larger size - it's a wasted resource.
stangboy
Founding Member
I'm glad this came up. I just finished putting 185s, f303, and Edelbrock Performer intake on my car last weekend. I reached my 500 miles over the weekend and I've been feeling my car out. I rebuilt my bottom end too and I put in stock replacement forged piston. I didn't know they were stock replacement pistons until I check for clearance. The clearance issue is the edge of the intake valve just barely goes outside of the valve relief. I had to slightly notch the pistons and I didn't have that clearance issue anymore. Now, as for the power that the motor is making now. It starts pulling hard at about 3000rpms but it pulls like a raped ape at 4000rpms all the way to redline...I can't wait to get a chip so I can get rid of that damn rev limiter. If you have nice sticky tires and launch hard off the line you won't be disappointed. I'm very pleased with it. I'm supposed to be racing a friend of mine tonight. He has a 90GT with a 306, Trickflow heads, nice solid lift cam(flat tappet), GT40 intake, 65mm TB, 1 5/8 e/l headers, 4.10s, and Nitto DRs.
I'm not sure how the race will be but I just want to see how my car compares. I think the weight difference might be the determining factor but we shall see.
Oh, I forgot to mention that I got the 185s because I plan to get a 331 shortblock soon. I didn't want to use 165s on a 331 and I didn't want to have to sell the 165s and buy the 185s.
I'm not sure how the race will be but I just want to see how my car compares. I think the weight difference might be the determining factor but we shall see.
Oh, I forgot to mention that I got the 185s because I plan to get a 331 shortblock soon. I didn't want to use 165s on a 331 and I didn't want to have to sell the 165s and buy the 185s.
Micheal; Ed was definately thinking along those lines. With anything less than a 3000 stall in an aod like mine or a mostly street/some strip combo, the 185's are going to kill the bottom end torque until you build revs. When I decided to go with the 331, he was much more willing to recommend the 185's.
Michael Yount
Mustang Master
Davs - "the 185's are going to kill the bottom end torque until you build revs"
I thought so too - but I've revised my thinking. There've been a couple of guys who posted here and on Corral (ndmp40) that have built 302/185 combo's with the stock HO cam and have amazed me with how strong the bottom end is. Someone up above said it - if it's cammed properly, the 185's can support good bottom end production. Not that the 165's won't work well too.
I thought so too - but I've revised my thinking. There've been a couple of guys who posted here and on Corral (ndmp40) that have built 302/185 combo's with the stock HO cam and have amazed me with how strong the bottom end is. Someone up above said it - if it's cammed properly, the 185's can support good bottom end production. Not that the 165's won't work well too.
MustangPunk302
Founding Member
Michael Yount said:
ndmp40's bottom end is so strong because the stock intake and small tb. It allows the air to come in super fast at lower rpm (and still prolly isn't using the heads to max) and just chokes the motor for air at higher rpm..
Besides we all know what cures a weak low end or a lumpy as hell cam.. Gears
Michael Yount
Mustang Master
MustangPunk - I see it differently than you - he's got mega hours into porting the stock intake; it flows quite well -- in fact from reading his posts, I believe the engine/combo was done in large part to see just how well the stock cam and intake could be made to work - any intake that supports almost 400 HP on the engine dyno flows quite well. You can't pin it on his intake. Throttle body size will ultimately restrict total airflow into the engine - but it has virtually no bearing at all on the runner/port flow/velocity equation you allude to. That tract begins at the manifold plenum - and in the case of the long runner efi intakes, the throttle body is well upstream of that. Besides - he's not the only one that's done it; others have done it with proven well-flowing aftermarket intakes.
In my opinion gears only mask a soft bottom end problem - they don't cure it. If you want to be able to tool up relatively steep hills in 4th and 5th at 1100 rpm or so without downshifting, you need bottom end - no way around it.
In my opinion gears only mask a soft bottom end problem - they don't cure it. If you want to be able to tool up relatively steep hills in 4th and 5th at 1100 rpm or so without downshifting, you need bottom end - no way around it.
