Has anyone put in a performance cam - i.e. dbilas?

[dallarax19]

I am looking for feedback from anyone that has put a performance cam in their engine. How did it work? Did you need to degree it in? Was there any special process for the install? I would appreciate the help.

[jmettee]

I don't know what 'dbilas' is, but I did install DMC-CA cams. The heads have to come off, so you're talking valve job & cylinder head cleanup. You also need to get rid of the stock muffler as it's the single most restrictive item in the system. Exhaust manifolds/crossover pipe are next most restrictive. I went the route of keeping the manifolds & crossover, but have a Flowmaster muffler. It really livened the car up & one day I will likely do headers.

Timing is set at 17 or 18 degrees & I use 89 octane to avoid ping.


http://www.youtube.com/watch?v=S_7rzp44gqU

[dallarax19]

I don't know the specs on the DMC cam so I don't really know what you had to do to set it up. I have installed several cams in 4cylinders but they needed to be degreed out and needed a vernier (adjustable) cam gear to set it. The cam gears in the PRV look to be stamped and there doesn't look to be room to fit an adjustable pully. My guess is you are limited on timing of the chain link. I have not done the math to see how much the timing could be off. I figured I would ask around first to see how people have installed the cam; like what did they do exactly. I have not had a good look at the exhaust port yet but it looks like there is an air injection port blocking the port exit. I think removing that plus a good blending of the ports would go along way on this guy. The icing on the cake would be a set of high lift cams with moderate duration.

some background on my project
http://dmctalk.org/showthread.php?5960-Looking-for-technical-information-PRV&highlight=dallarax19

dbilas cams
http://www.dbilas-shop.com/advanced_search_result.php?XTCsid=qreha1pk2i6kveq8 hijivj0nn3&keywords=alpine&x=-949&y=-379

[vwdmc16]

I believe the cams are just installed like a stock cam nothing different.

There are no air injection systems on these engines, the port should be open, not sure what you saw then.

[BABIS]

I have dbilas camshafts in my engine ;) you have to send yours for regrind.. great service, super fast and good price at all.
in the end I chose a 280° profile for a 2.8 atmo Alpine , with custom made matching pistons with 10,8:1 CPR..

[jmettee]

As far as I know, all DMC cams are simply bolt-in without any other engine adjustments. The stock cam timing gears just bolt on & have no adjustment.

I don't remember the values of the DMC-CA cams vs. the stock numbers. I vaguely remember stock being a .190" lift & DMC-CA being a .275" lift, but not 100% sure & also don't know the duration values. We're pretty limited with this engine & not many options out there to make it matter in the scheme of things.

You should hit up Josh from Delorean Performance. He has done quite a bit of engine stuff including port/polish & found it's not really worth the effort. I believe there's a thread on this forum where he discusses his findings with dyno results.

[BABIS]

As far as I know, all DMC cams are simply bolt-in without any other engine adjustments. The stock cam timing gears just bolt on & have no adjustment.

I don't remember the values of the DMC-CA cams vs. the stock numbers. I vaguely remember stock being a .190" lift & DMC-CA being a .275" lift, but not 100% sure & also don't know the duration values. We're pretty limited with this engine & not many options out there to make it matter in the scheme of things.

You should hit up Josh from Delorean Performance. He has done quite a bit of engine stuff including port/polish & found it's not really worth the effort. I believe there's a thread on this forum where he discusses his findings with dyno results.

reprofiled camshafts start to work only with some serious modifications to the heads, like in this engine :


http://img89.imageshack.us/img89/4585/26ax.png

http://img824.imageshack.us/img824/1224/w16.png

http://img607.imageshack.us/img607/5938/dncn.png

[dallarax19]

The pictures are very helpful. All my analysis says the bang for the buck is in exhaust porting and a high lift cam - see link in earlier post with a sensitivity analysis. The pics show the feature I was referring to - air injection or some other emissions deal. There is a passage that goes from the exhaust port floor to the manifold flange surface.

I will try to find the post you were referring to for porting. I don't really know how close the water jacket is to the port wall and before I start attacking it with a burr I would like to get some feedback - not sure how good the section cuts (technical drawings) of the ports are relative to reality. At the moment I am about 2/3 through the clean up of the castings for the block and covers and will be getting to the heads this weekend. I will be do port matching/blending to improve the flow. Flow bench and port data would be great if there is a post on that too so if you have it shoot me the link.

[DMCMW Dave]

There is a passage that goes from the exhaust port floor to the manifold flange surface.

.

It is a non-used exhaust air injection passage. You can block it off. Just avoid cutting into it. . . .

[dallarax19]

Filled air injection port:
http://i54.photobucket.com/albums/g89/dallarax19/DSC01490.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01490.jpg.html)
http://i54.photobucket.com/albums/g89/dallarax19/DSC01489.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01489.jpg.html)
http://i54.photobucket.com/albums/g89/dallarax19/DSC01496.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01496.jpg.html)
http://i54.photobucket.com/albums/g89/dallarax19/DSC01723.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01723.jpg.html)


My cams and springs arrived today from Germany
http://i54.photobucket.com/albums/g89/dallarax19/DSC01728.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01728.jpg.html)
http://i54.photobucket.com/albums/g89/dallarax19/DSC01729.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01729.jpg.html)
http://i54.photobucket.com/albums/g89/dallarax19/DSC01733.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01733.jpg.html)
http://i54.photobucket.com/albums/g89/dallarax19/DSC01735.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01735.jpg.html)

Basis for cam selection:
http://i54.photobucket.com/albums/g89/dallarax19/EffecitivityChart.jpg (http://s54.photobucket.com/user/dallarax19/media/EffecitivityChart.jpg.html)

I have not degreed them yet but the caliper check of the lobe vs base circle shows it is the right cam. Good news is I have nearly all the parts but the bad news is I have run out of time for this year. Looks like it will be set for next spring.

[BABIS]

what they have done to the valves springs?

[jerzybondov]

For what it's worth, I've just taken my reprofiled cams out of my engine (a B28E) as they'd eaten the rockers. Worn them down massively. Put stock cams back in. They were nice for a while when they were first in, but ultimately not worth it IMO given all the hassle I've been through since.

[dallarax19]

On the cam rocker wear how many miles (or kilometers) were on car since the install and what kind of oil were you running? How aggressive was the cam profile? You wouldn't happen to have degreed it out to check the ramp up/down profile? I will throw out the question to the UK Alpine guys and a couple of other folks to see if they have had the same issue and if so what they did. Maybe hardening the surface of the rocker pads or likely they will suggest later year alloy rockers. I assume after that you now have a set of cams for sale - figures right?

I have not yet measured the spring dims to compare to stock. I will likely do so this weekend. I wanted new springs just because of issues I have had in the past with other engines. I do not know the age or history of springs in the engine but with the high lift cam I want to know they will do the job. I also know not all springs are created equally - these were "race springs"

IAP "RACE SPRINGS" for a Fiat - maybe 2000 miles and reved up 7500rpm
http://i54.photobucket.com/albums/g89/dallarax19/120_2033.jpg (http://s54.photobucket.com/user/dallarax19/media/120_2033.jpg.html)

Fortunately Crane and Isky offered springs that fit the car and were tried and proven. I rev them up to 9500rpm without issue. I am putting faith in the French Alpine guys recommendation that the Dbilas springs will do the job. They have been pretty spot on their facts so far.

[Delorean Industries]

I never trust the stock springs especially on an engine that has been sitting. With the valve train timed properly the springs are sitting loaded at different tensions for long periods of time. Like anything this will stress the component. More or less depending on where the rocker is sitting on the cam lobe for that cylinder.

The biggest thing to take into account on regrinds. Base circle orientation is very important. To break it down as simply as possible: your center line to the top of the lobe to the lowest point on the base circle needs to match consistently from lobe to lobe on the intake and exhaust. If your lowest point isn't the same and you adjust your valves by degrees of rotation on the crankshaft you will be out of adjustment. We do not have this problem as our grinds are of a high quality. I guarantee on some of the other grinds floating around if adjusted by crankshaft degree the valve train will be noisy. The only way to properly adjust a low end regrind is to find the exact low spot on the the base circle and adjust at that point.

[jerzybondov]

On the cam rocker wear how many miles (or kilometers) were on car since the install and what kind of oil were you running? How aggressive was the cam profile? You wouldn't happen to have degreed it out to check the ramp up/down profile? I will throw out the question to the UK Alpine guys and a couple of other folks to see if they have had the same issue and if so what they did. Maybe hardening the surface of the rocker pads or likely they will suggest later year alloy rockers. I assume after that you now have a set of cams for sale - figures right?

I started to have running issues within 2000 miles of putting the reprofiled cams in the car. I was running 15W40 semi synthetic, although hadn't run the cams in - as I'd figured both cam and rocker were still 'used' rather than brand new. This may have been an error. The cams were reground to a 'fast road' set up by these guys:
http://www.kentcams.com/ which was the middle of three reprofiles offered - (mild / fast road / race).

I don't have any of the particular measurements for the cams, but I'm going to send them back to Kent Cams for them to measure and tell me what wear - if any - is on them. I will post the results. If they are saleable, then they will be for sale...

[dallarax19]

Stock Valve Spring
#active coils 5.5, total coils 7.25
wire dia = 4.21mm
OD = 30.11mm
ID = 21.59
Free Length = 47.55

Dbilas Valve Spring
#active coils 4, total coils 5.75
wire dia = 3.9mm
OD = 30.94mm
ID = 23.1mm
Free Length = 49.36mm


Lots and lots of time porting
http://i54.photobucket.com/albums/g89/dallarax19/DSC01776.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01776.jpg.html)

Before
http://i54.photobucket.com/albums/g89/dallarax19/DSC01773.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01773.jpg.html)

After
http://i54.photobucket.com/albums/g89/dallarax19/DSC01778.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01778.jpg.html)

Exhaust
http://i54.photobucket.com/albums/g89/dallarax19/DSC01780.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01780.jpg.html)

http://i54.photobucket.com/albums/g89/dallarax19/Slide1-4.jpg (http://s54.photobucket.com/user/dallarax19/media/Slide1-4.jpg.html)
A bit more checking
http://i54.photobucket.com/albums/g89/dallarax19/DSC01748.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01748.jpg.html)
http://i54.photobucket.com/albums/g89/dallarax19/DSC01781.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01781.jpg.html)

http://i54.photobucket.com/albums/g89/dallarax19/DSC01777-1.jpg (http://s54.photobucket.com/user/dallarax19/media/DSC01777-1.jpg.html)

I have to do a final check of each port with the calipers and do some final blending and finally done!