Looking at a used set of aluminum Yates heads.
Titanium valves, 2.15 intake & 1.6 exhaust.
T&D rockers.
Are these heads any good? (Quality/Performance)
What should I pay?
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Steve,
As far as I am aware, your motor has a set of C302 heads on it, with the appropriate intake & exhaust manifolds. Cleveland heads really don't get much better than that. I would not trade my C302 heads in on a set of Yates heads, never!
The Yates heads are good heads, but they are NOT Cleveland heads. They have no side cant to the intake valve, what this means to you is that your motor would require new pistons, AND there are possible issues with the intake & exhaust manifolds too. I have no hands on experience with Yates heads to be absolutely sure; I've been told Yates & SVO intake manifolds are interchangeable. If so, you could use your existing intake. If not, you would have to purchase a Yates intake. The Yates exhaust port is rectangular & the SVO exhaust port is round. I'm not sure about the compatibility of port heights or bolt patterns between the 2 heads. There are Pantera owners running Yates heads, I don't know what they have done regarding their exhaust systems.
Dan Jones, your experience would be welcomed to fill in the gaps.
The point I would like to get across is that the C302 heads can make all the horsepower a street motor is capable of making, and then some.
Your friend on the DTBB, George
As far as I am aware, your motor has a set of C302 heads on it, with the appropriate intake & exhaust manifolds. Cleveland heads really don't get much better than that. I would not trade my C302 heads in on a set of Yates heads, never!
The Yates heads are good heads, but they are NOT Cleveland heads. They have no side cant to the intake valve, what this means to you is that your motor would require new pistons, AND there are possible issues with the intake & exhaust manifolds too. I have no hands on experience with Yates heads to be absolutely sure; I've been told Yates & SVO intake manifolds are interchangeable. If so, you could use your existing intake. If not, you would have to purchase a Yates intake. The Yates exhaust port is rectangular & the SVO exhaust port is round. I'm not sure about the compatibility of port heights or bolt patterns between the 2 heads. There are Pantera owners running Yates heads, I don't know what they have done regarding their exhaust systems.
Dan Jones, your experience would be welcomed to fill in the gaps.
The point I would like to get across is that the C302 heads can make all the horsepower a street motor is capable of making, and then some.
Your friend on the DTBB, George
> Looking at a used set of aluminum Yates heads.
There are a wide range of Yates heads: C3L, C3H, SC1 and D3. Actually, the SC1
and D3 are not technically Yates heads (the cant angle in back in the D3's,
BTW) but most people lump them in.
> I've been told Yates & SVO intake manifolds are interchangeable.
Intakes are *not* interchangeable. A C302B intake will physically bolt up to
to early C3L Yates heads but the ports are shifted fore-and-aft. Later heads
like the C3H have higher intake ports and the intake manifold bolts
perpendicular to head. The valve locations are not the same either, so you'll
need new pistons. Most but not all Yates heads have very small combustion
chambers, on the order of 37 to 43 cc's so you'll need a dished piston to run
pump gas.
> The Yates exhaust port is rectangular & the SVO exhaust port is round.
> I'm not sure about the compatibility of port heights or bolt patterns between
> the 2 heads. There are Pantera owners running Yates heads, I don't know what
> they have done regarding their exhaust systems.
I've never tried to bolt C302B headers to C3L/C3H heads but the bolt pattern
looks similar. They do take a different p/n header gasket so they aren't
identical. Later heads like the D3 have higher port locations.
> The point I would like to get across is that the C302 heads can make all the
> horsepower a street motor is capable of making, and then some.
The early Yates heads did not flow any better (worse in many cases) than the
C302's but were optimized for restrictor plate racing requiring very high
static compression ratios. This required reducing the cant angle to make a
shallower chamber. The valve angles were changed to 7.5 and 8.0 degrees with
no side cant to reduce piston valve relief depths and permit higher ring
packaging. The resulting head requires an aftermarket rockershaft system,
different intake, pistons, valves, and pushrods compared to C302B's and 4V's.
Dan Jones
There are a wide range of Yates heads: C3L, C3H, SC1 and D3. Actually, the SC1
and D3 are not technically Yates heads (the cant angle in back in the D3's,
BTW) but most people lump them in.
> I've been told Yates & SVO intake manifolds are interchangeable.
Intakes are *not* interchangeable. A C302B intake will physically bolt up to
to early C3L Yates heads but the ports are shifted fore-and-aft. Later heads
like the C3H have higher intake ports and the intake manifold bolts
perpendicular to head. The valve locations are not the same either, so you'll
need new pistons. Most but not all Yates heads have very small combustion
chambers, on the order of 37 to 43 cc's so you'll need a dished piston to run
pump gas.
> The Yates exhaust port is rectangular & the SVO exhaust port is round.
> I'm not sure about the compatibility of port heights or bolt patterns between
> the 2 heads. There are Pantera owners running Yates heads, I don't know what
> they have done regarding their exhaust systems.
I've never tried to bolt C302B headers to C3L/C3H heads but the bolt pattern
looks similar. They do take a different p/n header gasket so they aren't
identical. Later heads like the D3 have higher port locations.
> The point I would like to get across is that the C302 heads can make all the
> horsepower a street motor is capable of making, and then some.
The early Yates heads did not flow any better (worse in many cases) than the
C302's but were optimized for restrictor plate racing requiring very high
static compression ratios. This required reducing the cant angle to make a
shallower chamber. The valve angles were changed to 7.5 and 8.0 degrees with
no side cant to reduce piston valve relief depths and permit higher ring
packaging. The resulting head requires an aftermarket rockershaft system,
different intake, pistons, valves, and pushrods compared to C302B's and 4V's.
Dan Jones
Thank you Mr. Jones.
Thanks guys,
I guess I should have explained more of the thoughts I have. See, I have a 373C stroker with the C302 heads, however the power didn't come thru like I hoped it would. (405 HP
) The answer is to rebuild the engine to make the power. Yes, I believe the heads I have will do this. I happened to find a gentleman in Indiana who has a 408 stroker for sale. This engine is using a Dart block with the previously discussed Yates heads. I know the value of the block, but not the heads. I guess I was just wondering what you guys would have to say about the parts. The 408 has Carillo rods and all forged internals. 13:0 to 1 compression and requires 110 race fuel. Engines producing 688 horsepower.
I thought this may be an alternative to the costly rebuild of the engine I have now. I can purchase this 408 for around $6500. Then just keep my current engine so that if I ever sell the car there would be a complete engine that would be a little more user friendly for the next owner.
My brother does not believe this engine would work for street use, suggesting that an engine of this nature would only make this power on the high end and have a poor torque curve for drivability.
I'm not sure what to think.
Steve
I guess I should have explained more of the thoughts I have. See, I have a 373C stroker with the C302 heads, however the power didn't come thru like I hoped it would. (405 HP
) The answer is to rebuild the engine to make the power. Yes, I believe the heads I have will do this. I happened to find a gentleman in Indiana who has a 408 stroker for sale. This engine is using a Dart block with the previously discussed Yates heads. I know the value of the block, but not the heads. I guess I was just wondering what you guys would have to say about the parts. The 408 has Carillo rods and all forged internals. 13:0 to 1 compression and requires 110 race fuel. Engines producing 688 horsepower. I thought this may be an alternative to the costly rebuild of the engine I have now. I can purchase this 408 for around $6500. Then just keep my current engine so that if I ever sell the car there would be a complete engine that would be a little more user friendly for the next owner.
My brother does not believe this engine would work for street use, suggesting that an engine of this nature would only make this power on the high end and have a poor torque curve for drivability.
I'm not sure what to think.
Steve
Steve,
listen to your brother
that is not a street motor
fixing what you have is the most cost effective way to proceed. Your motor with new pistons to lower compression and with a good hydraulic roller cam is capable of 450 ft/lbs torque and 450 bhp or more, in a streetable package you would be quite happy with.
George
listen to your brother
that is not a street motor
fixing what you have is the most cost effective way to proceed. Your motor with new pistons to lower compression and with a good hydraulic roller cam is capable of 450 ft/lbs torque and 450 bhp or more, in a streetable package you would be quite happy with.
George
Yeah, suppose you are right.
I'm looking at over $8000 to rebuild and come out with more power than the car has now. Guess I was just hoping to stumble across a cheaper alternative. Let someone else throw down the money up front and not me!
George, I can't say that I would happy with the 450/450. I would like to see 600. This probably seems silly to you guys, but the car has the look of a true exotic. I want it to have the capabilities to run down anything on the road if I need.
My dad use to always tell me that it was better to have a gun and not need it then to need a gun and not have it!
Thanks for the info though, I would think between you and Dan, there will be nothing we can't figure out!
Steve
I'm looking at over $8000 to rebuild and come out with more power than the car has now. Guess I was just hoping to stumble across a cheaper alternative. Let someone else throw down the money up front and not me!
George, I can't say that I would happy with the 450/450. I would like to see 600. This probably seems silly to you guys, but the car has the look of a true exotic. I want it to have the capabilities to run down anything on the road if I need.
My dad use to always tell me that it was better to have a gun and not need it then to need a gun and not have it!
Thanks for the info though, I would think between you and Dan, there will be nothing we can't figure out!
Steve
Steve,
I quoted 450 because it is EASY to obtain with your parts, and relatively inexpensive. You can make more than 450 bhp with your parts, but at 500 bhp you are pushing the limit of the production Cleveland block. At 600 bhp you will be spending a lot of money replacing broken ZF parts.
At 500 bhp you'll have enough power to meet 99.99% of any challengers on the road. You'll NEVER have enough to be unbeatable.
George
I quoted 450 because it is EASY to obtain with your parts, and relatively inexpensive. You can make more than 450 bhp with your parts, but at 500 bhp you are pushing the limit of the production Cleveland block. At 600 bhp you will be spending a lot of money replacing broken ZF parts.
At 500 bhp you'll have enough power to meet 99.99% of any challengers on the road. You'll NEVER have enough to be unbeatable.
George
The compression alone makes the engine you reference an impractical street engine. With that kind of squeeze, and Yates heads on a Dart block, my guess is it would not be cammed accordingly either. If you did buy it, it’s doubtful that the short block would be useable as is. You likely would require different pistons as well.
I wouldn’t get too wrapped around the axle about the peak HP figure. It’s a pretty common misconception that leads toi a lot over over cammed and over carbed engine builds. I realize I’m about to start the whole thing all over again but strictly speaking, race engines make poor street engines and vice-versa. It’s an artful compromise for street performance. For the street, you need to consider many things including, reliability, required maintenance, required fuel, starting, idling, cost, etc. Few of the aforementioned are of much concern on purpose built race engines.
HP statements are merely a statement about that rate at which you’re making torque at a specific rpm. However, it rarely tells the whole story. But….everyone tends to compares peak HP figures and believe this means the engine will outperform others of lesser peak HP. For street cars and virtually every form of racing, maximizing the area under the torque curve in the rpm range you live will add up to harder acceleration and general performance. Drag racing usually can tolerate the narrowest rpm bands so peaky engines are the norm. IMO, the issue of reliability is a big driver and is a divergent parameter with power. Many people with the pocket book to put a race engine in a street car don’t have the skill or desire to maintain it like a race engine requires. Nascar engines don’t run in the same band as NHRA. That’s the difference between being built to live for 500 miles versus ¼ of a mile at a time.
From my perspective, street performance means 3000-6000 rpm. Will I ever see above or below that range? Of course. However, if you look at your tach during spirited street driving that covers a lot of ground. Some would bias my range up 500-1000 rpm or so but that’s all part of the compromise. With a 427 CI small block and hydraulic roller, I’m North of 500 ft-lbs at 3250 rpm, peak torque of 555 ft-lbs at 4750, and high 400’s at the top end of that rpm range. I’d have to go look at my dyno sheet (or retrieve my calculator) to tell you the HP but it will undoubtedly be well into the 500s and occur somewhere between peak torque and 6krpm. Will you win the Silver State with this engine? -Nope. But, for my money, any time you get a low maintenance (small block) street engine to give you North of 500 ft-lbs torque over that range, it’s bound to put a smile on your face. My 2 cents.
-Good luck with your build.
Kelly
I wouldn’t get too wrapped around the axle about the peak HP figure. It’s a pretty common misconception that leads toi a lot over over cammed and over carbed engine builds. I realize I’m about to start the whole thing all over again but strictly speaking, race engines make poor street engines and vice-versa. It’s an artful compromise for street performance. For the street, you need to consider many things including, reliability, required maintenance, required fuel, starting, idling, cost, etc. Few of the aforementioned are of much concern on purpose built race engines.
HP statements are merely a statement about that rate at which you’re making torque at a specific rpm. However, it rarely tells the whole story. But….everyone tends to compares peak HP figures and believe this means the engine will outperform others of lesser peak HP. For street cars and virtually every form of racing, maximizing the area under the torque curve in the rpm range you live will add up to harder acceleration and general performance. Drag racing usually can tolerate the narrowest rpm bands so peaky engines are the norm. IMO, the issue of reliability is a big driver and is a divergent parameter with power. Many people with the pocket book to put a race engine in a street car don’t have the skill or desire to maintain it like a race engine requires. Nascar engines don’t run in the same band as NHRA. That’s the difference between being built to live for 500 miles versus ¼ of a mile at a time.
From my perspective, street performance means 3000-6000 rpm. Will I ever see above or below that range? Of course. However, if you look at your tach during spirited street driving that covers a lot of ground. Some would bias my range up 500-1000 rpm or so but that’s all part of the compromise. With a 427 CI small block and hydraulic roller, I’m North of 500 ft-lbs at 3250 rpm, peak torque of 555 ft-lbs at 4750, and high 400’s at the top end of that rpm range. I’d have to go look at my dyno sheet (or retrieve my calculator) to tell you the HP but it will undoubtedly be well into the 500s and occur somewhere between peak torque and 6krpm. Will you win the Silver State with this engine? -Nope. But, for my money, any time you get a low maintenance (small block) street engine to give you North of 500 ft-lbs torque over that range, it’s bound to put a smile on your face. My 2 cents.
-Good luck with your build.
Kelly
"HP statements are merely a statement about that rate at which you’re making torque at a specific rpm. "
That's the shortest and sweetest description of the difference between HP and torque I've ever seen! And God knows those terms have been debated ad infinitum.
____
I don't know about you all, but for me, driving my car regularly means driving in the 2,000-4,000 rev range, stoplights, traffic, etc. The 4,000-6,000 range is not very practical for 90% of my driving.
Jeff
6559
That's the shortest and sweetest description of the difference between HP and torque I've ever seen! And God knows those terms have been debated ad infinitum.
____
I don't know about you all, but for me, driving my car regularly means driving in the 2,000-4,000 rev range, stoplights, traffic, etc. The 4,000-6,000 range is not very practical for 90% of my driving.
Jeff
6559