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I have a completely stock 1971 S2 spider 1750 spica injected. I'm looking to give it a little more top end, some people say go with euro cams for a decent butt dyno increase and I see Centerline has a 10.5mm cam they are calling euro plus.

My question is this: Will anything other than cam timing need to be modified in order to install and run a single 10.5mm cam on the exhaust side? Its a healthy low mileage engine (38k on the clock) and the spica is also healthy. At this moment I'm not looking to go nuts or do a wes ingram pump.

Thanks for any input in advance. I'm new to modifying alfa engines but I have experience wrenching and have a decent set of tools at my disposal.
 

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Alex Bassilia said:
...to install and run a single 10.5mm cam on the exhaust side
When you run mismatched cams in an Alfa, one "hotter" than the other, you typically put the hotter cam on the intake side - not the exhaust.

Will anything other than cam timing need to be modified in order to install and run a single 10.5mm cam
Most likely, your engine will handle an extra mm or so of lift with no interference problems. But no one on the internet can tell you that for certain. A lot depends on how much your head has been milled, how your valve guides are positioned, type of piston, cam timing, etc. etc.
 

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I have the 11.1mm Centerline cams in both intake and exhaust position.
I had the intake cam first with the Spica exhaust cam, then added the exhaust cam. Both cams timed at 102* lobe centers.
This is on a 2.0 Spica car at 5300 foot elevation.

Runs great!!
 

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I'm running the 11.1 on the intake and the 10.5 on the exhaust. When the head was RR'd a little more clearance was made for the 11.1. Also when the spica pump was RR'd, Wes produced a HP pump to match the higher performance. But to answer your question... with just the 10.5 in the intake you probably don't need another changes. I would give Wes a call to confine you don't need to do anything with the pump.
 

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I'm on a stock pump with no mods, and the pump is likely original.

Pulls strong and revs to 7,000 RPM.
 

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I would ask Centerline if there is a chance of interference between the cam lobes and the follower bores. Probably not, but I would ask. With a new cam, you will need to check and adjust valve clearances. As matter of course, you should confirm there is no piston/valve interference.

Is there a particular reason the Centerline camshaft is intended for the exhaust side? Normally the better cam would go on the intake side, as Jay pointed out above. While the engine will run ok using the stock lobe centers, it is likely that there is a benefit to slightly different cam timing.
 

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The way I understand it is this:
Hotter intake cam and keep stock exhaust cam. I had the 11.1 intake cam and ran it with stock exhaust cam.
Or, go 11.1 on the intake cam and the 10.5 on the exhaust.
Or, go 11.1 on both, which is what I ended up doing.
The upgrade to the 11.1 exhaust cam was really worth it.
 

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Discussion Starter #8
I would ask Centerline if there is a chance of interference between the cam lobes and the follower bores. Probably not, but I would ask. With a new cam, you will need to check and adjust valve clearances. As matter of course, you should confirm there is no piston/valve interference.

Is there a particular reason the Centerline camshaft is intended for the exhaust side? Normally the better cam would go on the intake side, as Jay pointed out above. While the engine will run ok using the stock lobe centers, it is likely that there is a benefit to slightly different cam timing.
Yes sorry that's my mistake I meant to write intake side. Head is not shaved it's all original. Is doing the valve shimming necessary? I would like to do it in the future but we are quickly approaching driving season here in Canada and I'd rather have time over the winter to get that done. I also don't absolutely need to upgrade the cam just yet. I was curious if it was a direct bolt in affair, the BB is infinitely more experienced than I am in what other factors could be important.
 

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You will need to have correct valve clearances (lash) set before running the engine with the new cam. You won't know with absolute certainty what will be required until you install the new cam and measure clearances. And, you might as well check and potentially adjust clearances on the exhaust side as well. Just normal, periodic maintenance. It should not cause excessive downtime. Maybe a week if you have to order new shims.
 

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Discussion Starter #10
You will need to have correct valve clearances (lash) set before running the engine with the new cam. You won't know with absolute certainty what will be required until you install the new cam and measure clearances. And, you might as well check and potentially adjust clearances on the exhaust side as well. Just normal, periodic maintenance. It should not cause excessive downtime. Maybe a week if you have order new shims.
Ok noted. Thanks for your help!
 

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I have a completely stock 1971 S2 spider 1750 spica injected. I'm looking to give it a little more top end, some people say go with euro cams for a decent butt dyno increase and I see Centerline has a 10.5mm cam they are calling euro plus.

My question is this: Will anything other than cam timing need to be modified in order to install and run a single 10.5mm cam on the exhaust side? Its a healthy low mileage engine (38k on the clock) and the spica is also healthy. At this moment I'm not looking to go nuts or do a wes ingram pump.

Thanks for any input in advance. I'm new to modifying alfa engines but I have experience wrenching and have a decent set of tools at my disposal.
Do you know what the cam timing will be with the new cam?

miles is not the only factor when changing cams. How old are those valve seals? Are they OEM?
Are you prepared to experience an increase in oil consumption?
IMHO: save your money and energy until you’re ready for a head rebuild and Spica modifications. Get your cams, new modern seals and higher performance valve springs.
If you want to squeeze some extra umpf.. get some bolt on mods first: headers and exhaust, electric cooling fan....
 

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No to the above post.
All the info that you need is on the Centerline web site. Info on installation tips, valve lash, timing, etc. Cam comes with timing template. Pull an all-nighter, slam the cam, pedal to the metal at sun rise. Miles of smiles.
 
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