Help With Blower Cam.
01-20-2005, 07:52 AM
#21
MarineKinetics
Platinum Member
Re: Help With Blower Cam.
GPM
No, the lobes in the blown 383, are CamMotion not Comp, and not even close to the lobes in this thread.
The “Race Only” designation for the lobes 3299/3295 recommended in post #11 is actually Comp Cams designation for the lobe. By referencing page 246 of the Comp Catalog at this page the specified lobes are clearly marked in bold print as Race Only.
http://www.compcams.com/Technical/Ca...ML/JPG/246.jpg
Also on page 15 the print version of the 2005 Comp Cams Master Lobe Profile Catalog they issue additional information.
“These lobes are very aggressive and are “race only” designed lobes”
I posted this information because anyone who would seriously consider having the “Cheater HR Lift Rule Competition Hydraulic Rollers” lobe ground on a BBC core, for a marine application, should be aware that some extensive valve train tweaking would be necessary to have any reasonable expectation of any durability. My question was to you the advantage of the “restricted rule”(their design is essentially a compromise) lobes over all of the other lobe profiles available.
Bob
No, the lobes in the blown 383, are CamMotion not Comp, and not even close to the lobes in this thread.
The “Race Only” designation for the lobes 3299/3295 recommended in post #11 is actually Comp Cams designation for the lobe. By referencing page 246 of the Comp Catalog at this page the specified lobes are clearly marked in bold print as Race Only.
http://www.compcams.com/Technical/Ca...ML/JPG/246.jpg
Also on page 15 the print version of the 2005 Comp Cams Master Lobe Profile Catalog they issue additional information.
“These lobes are very aggressive and are “race only” designed lobes”
I posted this information because anyone who would seriously consider having the “Cheater HR Lift Rule Competition Hydraulic Rollers” lobe ground on a BBC core, for a marine application, should be aware that some extensive valve train tweaking would be necessary to have any reasonable expectation of any durability. My question was to you the advantage of the “restricted rule”(their design is essentially a compromise) lobes over all of the other lobe profiles available.
Bob
Last edited by rmbuilder; 01-20-2005 at 07:55 AM.
01-20-2005, 08:23 AM
#22
Re: Help With Blower Cam.
I actually meant the duration, BOB, It's probably the biggest cam I've seen on OSO.
Back to the Comp cam, It was only a suggestion, the shorter seat timing would idle better, the bigger .200 duration would make more hp. and maybe the low lift would actually work without hitting retainers to guides. That would have to be checked. My
suggestion would be see what fits before making the decision.
Back to the Comp cam, It was only a suggestion, the shorter seat timing would idle better, the bigger .200 duration would make more hp. and maybe the low lift would actually work without hitting retainers to guides. That would have to be checked. My
suggestion would be see what fits before making the decision.
01-20-2005, 10:38 AM
#23
Guest
Posts: n/a
Re: Help With Blower Cam.
GPM,
It is not a good idea to use those lobes in a marine application. Some of those lobes require the changing of valve springs after a weekend of racing. They also require "modified" hyd roller lifters and the use of restrictor pushrods. Your thinking is going in the right direction but the "liveability of the engine" would be greatly sacrificed for the gain.
Chris
It is not a good idea to use those lobes in a marine application. Some of those lobes require the changing of valve springs after a weekend of racing. They also require "modified" hyd roller lifters and the use of restrictor pushrods. Your thinking is going in the right direction but the "liveability of the engine" would be greatly sacrificed for the gain.
Chris
01-20-2005, 12:57 PM
#24
Re: Help With Blower Cam.
Originally Posted by cstraub69@comcast
GPM,
It is not a good idea to use those lobes in a marine application. Some of those lobes require the changing of valve springs after a weekend of racing. They also require "modified" hyd roller lifters and the use of restrictor pushrods. Your thinking is going in the right direction but the "liveability of the engine" would be greatly sacrificed for the gain.
Chris
It is not a good idea to use those lobes in a marine application. Some of those lobes require the changing of valve springs after a weekend of racing. They also require "modified" hyd roller lifters and the use of restrictor pushrods. Your thinking is going in the right direction but the "liveability of the engine" would be greatly sacrificed for the gain.
Chris
01-20-2005, 01:55 PM
#25
Guest
Posts: n/a
Re: Help With Blower Cam.
Flat Tappets:
I would strongly suggest upgrading to hyd roller if you can. In my industry lifter production of flat tappets was greatly affected when 1 company was closed due to financial reasons and one company just quit producing flat tappets. This coincided with the gov. mandating that since OEM's weren't producing cars that needed harmful additives that reduced wear in flat tappet applications that the oil companies were banned from putting these additives in except for oil to be used in AG vehicles. And last but not least the parkariztion of lifter faces had become so expensive it had to be dropped. . .critical in initial cam lifter break in.
Since this the amount of cams going flat has gone through the roof with cams getting blamed. Well it is not their fault. The lifters are to blame. The crown on some lifters is none existant to minimal. The reduction in the amount of crown reduces the lifters spinning motion which it must do to work.
Now lifters from China are entering the country through sub par sources. Although some of the stuff from over there is good quality when QC is inforced, some of the stuff is copy cat.
If you half to use flat tappets here's what I would suggest:
1. Get some GM EOS (engine oil suppliment). This is a must when breaking the cam in.
2. Buy lifters from the camshaft mfg. Most now will do nothing if you mix lifters with their cams.
3. Use light break in springs and don't let the engine go below 2000 rpm for the first 30 minutes.
4. Use a straight 30 oil during break in.
5. Some engine builders over fill the crank case by 5 or 6 qts. This won't hurt anything at low rpm below 3000, but what it will do is allow the crank and rods to splash and throw oil on the cam for extra lube. Once cam is broke in, fill pan with correct amount of oil.
6. Last but not least cross your fingers.
Chris
I would strongly suggest upgrading to hyd roller if you can. In my industry lifter production of flat tappets was greatly affected when 1 company was closed due to financial reasons and one company just quit producing flat tappets. This coincided with the gov. mandating that since OEM's weren't producing cars that needed harmful additives that reduced wear in flat tappet applications that the oil companies were banned from putting these additives in except for oil to be used in AG vehicles. And last but not least the parkariztion of lifter faces had become so expensive it had to be dropped. . .critical in initial cam lifter break in.
Since this the amount of cams going flat has gone through the roof with cams getting blamed. Well it is not their fault. The lifters are to blame. The crown on some lifters is none existant to minimal. The reduction in the amount of crown reduces the lifters spinning motion which it must do to work.
Now lifters from China are entering the country through sub par sources. Although some of the stuff from over there is good quality when QC is inforced, some of the stuff is copy cat.
If you half to use flat tappets here's what I would suggest:
1. Get some GM EOS (engine oil suppliment). This is a must when breaking the cam in.
2. Buy lifters from the camshaft mfg. Most now will do nothing if you mix lifters with their cams.
3. Use light break in springs and don't let the engine go below 2000 rpm for the first 30 minutes.
4. Use a straight 30 oil during break in.
5. Some engine builders over fill the crank case by 5 or 6 qts. This won't hurt anything at low rpm below 3000, but what it will do is allow the crank and rods to splash and throw oil on the cam for extra lube. Once cam is broke in, fill pan with correct amount of oil.
6. Last but not least cross your fingers.
Chris
01-20-2005, 02:04 PM
#26
MarineKinetics
Platinum Member
Re: Help With Blower Cam.
I think a post may have been lost during maintenance where fastlane40 said he wanted to keep the non-adjustable rockers also. If that is the case, it limits the options available.
Bob
Bob
01-20-2005, 05:32 PM
#30
Registered
Re: Help With Blower Cam.
Several friends of mine and I have run the 288/296 (231*/239*) Ultradyne flat tappet hydraulic cam. However, the lift specs I recall used to be something more like .550"/.558" and then later it was changed to .550"/.575".
Merc used it in their 454cid 440hp Cyclone engines back in the 1980's. It is a little too large for a 454 in my opinion. I believe Merc also used the same exact cam in their 482cid 460hp engine if that tells you anything. Merc ran both of these engines with a GIL exhaust system. I think you especially needed to at least run the GIL's with that cam in the 454 just to get it to work properly. I saw some guys use this cam while upgrading their 454cid 365hp Merc engines and while still retaining the stock Merc cast iron exhaust manifolds (very crude) and they were disappointed. Back then they didn't have GPS available to really see any gains. With the stock Merc cast iron exhaust they did happen to notice more torque...in the middle, but the cam needs to breath better, especially in a 454 and the GIL's helped a lot, but some guys couldn't afford to go out and by aftermarket exhausts. As time went on some were able to afford the GIL's or Stainless Marine exhausts and once they bolted them on they noticed much better performance and were much happier. I always liked that cam, but from what I know today I wouldn't recommend it any longer for a 454cid marine application---it's a bit too large.
By the way, my cousin still has one of those cams brand new in the box if anyone is interested.
Merc used it in their 454cid 440hp Cyclone engines back in the 1980's. It is a little too large for a 454 in my opinion. I believe Merc also used the same exact cam in their 482cid 460hp engine if that tells you anything. Merc ran both of these engines with a GIL exhaust system. I think you especially needed to at least run the GIL's with that cam in the 454 just to get it to work properly. I saw some guys use this cam while upgrading their 454cid 365hp Merc engines and while still retaining the stock Merc cast iron exhaust manifolds (very crude) and they were disappointed. Back then they didn't have GPS available to really see any gains. With the stock Merc cast iron exhaust they did happen to notice more torque...in the middle, but the cam needs to breath better, especially in a 454 and the GIL's helped a lot, but some guys couldn't afford to go out and by aftermarket exhausts. As time went on some were able to afford the GIL's or Stainless Marine exhausts and once they bolted them on they noticed much better performance and were much happier. I always liked that cam, but from what I know today I wouldn't recommend it any longer for a 454cid marine application---it's a bit too large.
By the way, my cousin still has one of those cams brand new in the box if anyone is interested.
