Roller Cam Bearings?
Platinum Member
12-20-2015, 12:41 PM
#12
.600 raised cam = no grinding rods.
10.6 deck = a lot less side loading on the piston with a big boy crank
Donovan pan rails = much better windage
And if you ever seen a Dart Race series block you would know it's a bad mofo and I just had to have it.
At this point I'll have a clean slate blank hull so it just made sense to to purchase the block. Machine shop bought it for a guy and the guy stuck them with the block. So I purchased it for a lot less than WD cost.
10.6 deck = a lot less side loading on the piston with a big boy crank
Donovan pan rails = much better windage
And if you ever seen a Dart Race series block you would know it's a bad mofo and I just had to have it.
At this point I'll have a clean slate blank hull so it just made sense to to purchase the block. Machine shop bought it for a guy and the guy stuck them with the block. So I purchased it for a lot less than WD cost.
12-20-2015, 02:05 PM
#14
.600 raised cam = no grinding rods.
10.6 deck = a lot less side loading on the piston with a big boy crank
Donovan pan rails = much better windage
And if you ever seen a Dart Race series block you would know it's a bad mofo and I just had to have it.
At this point I'll have a clean slate blank hull so it just made sense to to purchase the block. Machine shop bought it for a guy and the guy stuck them with the block. So I purchased it for a lot less than WD cost.
10.6 deck = a lot less side loading on the piston with a big boy crank
Donovan pan rails = much better windage
And if you ever seen a Dart Race series block you would know it's a bad mofo and I just had to have it.
At this point I'll have a clean slate blank hull so it just made sense to to purchase the block. Machine shop bought it for a guy and the guy stuck them with the block. So I purchased it for a lot less than WD cost.
Sounds like a nice build does it have keyway lifter bores? And now what crank and rods you going to use?
12-20-2015, 02:40 PM
#15
I feel your pain. I'm probably going to run the .937 Jesel tall bodies i already have (probably). Callies Crank and rods. Was considering the Molnar rods but having a set of pins that are almost double what the price of the rods are didn't sit very well. Everything was already bought and ready to go into the 10.2 block. I'll just buy a new belt and plate for the belt drive. Luckily the pan I had made has the Donovan pattern on it. All in all the change isn't to hard on the wallet. But if I had two motors I wouldnt even consider making the change.
12-20-2015, 02:58 PM
#16
I feel your pain. I'm probably going to run the .937 Jesel tall bodies i already have (probably). Callies Crank and rods. Was considering the Molnar rods but having a set of pins that are almost double what the price of the rods are didn't sit very well. Everything was already bought and ready to go into the 10.2 block. I'll just buy a new belt and plate for the belt drive. Luckily the pan I had made has the Donovan pattern on it. All in all the change isn't to hard on the wallet. But if I had two motors I wouldnt even consider making the change.
12-21-2015, 06:15 AM
#17
Registered
withe the reg bearing oil travels around cam and thru hole in bearings(why the oil holes must lined up) and that is the feed to the heads for rockers etc, roller bearing loose oil pressure at the cam it would seem to me and not supply as much up the the heads, now in drag race apps some engine builders run no oil to heads and only pour enough to lube everything for 1 run and know the valve covers are coming off after every run to ck springs etc...
12-21-2015, 07:05 AM
#18
Banned
A lot of guys have e gone from roller cam bearings back to babbitt because of valve train harmonics.. I personally have never seen any gains from the roller bearings. I know that in some cases babbitt bearings have shown more power. I would also not consider shimming cam bearings.
The heads are fed oil via the lifters which is a different oil circuit than the cam bearings. Cam bearings are usually fed after the mains and that's the end of that run and should have no effect on oil going to the top end. Also, roller cam bearings are splash fed, not pressurized like a babbitt bearing. Personally, I wouldn't lose a lot of sleep over a roller cam bearing as long as everything else is right like spring pressures, a forgiving cam lobe, the biggest push rods you can run and spot-on rocker geometry. Don't get caught up in thinking that just because you already have something, it's a good idea to use it just to save some $$$. If it's the wrong part, the money you think you might be saving could end up costing you way more in the long run. I will also add this: upgrading to the larger cam journal (and larger base circle)is one of the best upgrades you can do to an endurance engine. It would be a shame to have the potential of this new block (they made the cam tunnel that size for a reason) and not use it. Problem may be that you aren't running a big enough cam to really take advantage of it and in fact, there may not be a large journal core with a lobe small enough for you to use. What are your current cam specs?
The heads are fed oil via the lifters which is a different oil circuit than the cam bearings. Cam bearings are usually fed after the mains and that's the end of that run and should have no effect on oil going to the top end. Also, roller cam bearings are splash fed, not pressurized like a babbitt bearing. Personally, I wouldn't lose a lot of sleep over a roller cam bearing as long as everything else is right like spring pressures, a forgiving cam lobe, the biggest push rods you can run and spot-on rocker geometry. Don't get caught up in thinking that just because you already have something, it's a good idea to use it just to save some $$$. If it's the wrong part, the money you think you might be saving could end up costing you way more in the long run. I will also add this: upgrading to the larger cam journal (and larger base circle)is one of the best upgrades you can do to an endurance engine. It would be a shame to have the potential of this new block (they made the cam tunnel that size for a reason) and not use it. Problem may be that you aren't running a big enough cam to really take advantage of it and in fact, there may not be a large journal core with a lobe small enough for you to use. What are your current cam specs?
Last edited by horsepower1; 12-21-2015 at 07:12 AM.
12-21-2015, 10:00 AM
#19
I already have a 55mm cam with a 60mm barrel on it. Sourcing a 60mm cam core is not a big deal. I could have the cam in my hands tomorrow if I wanted it. But what really is to gain? .472/.465 lobes
The Race blocks actually come with a DRCE2 housing bore which is smaller the 55mm I had it opened up and was going to run a 60mm cam then my brain started working and I asked myself is it really worth it...
The Race blocks actually come with a DRCE2 housing bore which is smaller the 55mm I had it opened up and was going to run a 60mm cam then my brain started working and I asked myself is it really worth it...
12-21-2015, 10:44 AM
#20
Banned
I already have a 55mm cam with a 60mm barrel on it. Sourcing a 60mm cam core is not a big deal. I could have the cam in my hands tomorrow if I wanted it. But what really is to gain? .472/.465 lobes
The Race blocks actually come with a DRCE2 housing bore which is smaller the 55mm I had it opened up and was going to run a 60mm cam then my brain started working and I asked myself is it really worth it...
The Race blocks actually come with a DRCE2 housing bore which is smaller the 55mm I had it opened up and was going to run a 60mm cam then my brain started working and I asked myself is it really worth it...
