Cost to change camshafts

.PORSCHE. · 03-29-2014, 04:48 PM

I am planning to change my camshafts out for a different grind on my early 2.4 911 at some point in the foreseeable future. In order to save up for the work involved, can anyone please tell me how much I should expect to pay a mechanic to do this for me? Roughly how many hours of labor are involved? I am guessing the engine will have to be dropped to do this, right? Thanks!

yelcab1 · 03-29-2014, 05:19 PM

$2000

.PORSCHE. · 03-29-2014, 06:24 PM

Thanks. How many hours labor is that calculated on? Does the engine need to be removed from the car? Thanks.

Steve@Rennsport · 03-29-2014, 09:20 PM

Make sure your pistons have sufficient valve clearance for the new cams you are contemplating.

I've seen people make an expensive mistake by not making accurate measurements before starting the engine.

snbush67 · snbush67's Garage

Quote:

Originally Posted by .PORSCHE.

Thanks. How many hours labor is that calculated on? Does the engine need to be removed from the car? Thanks.

I think that to remove the engine, replace the cams, replace the engine and tune would take roughly 15- 20 hours. That's if everything goes right and nothing else is lurking that needs attention.

Yes, the engine needs to come out, that is the easiest part of the job.

pors1968 · pors1968's Garage

What is CIS MFI or carb that make diff on price.

.PORSCHE. · 03-30-2014, 04:22 AM

Thanks. It is a 2.4S engine with E cams at the moment. The plan will be to put original 911S cams in. The pistons are 2.4S Mahle, so they should have plenty of room for the more aggressive cams/valve lift. Am I right? It's an MFI engine, BTW. Does that make it more expensive? Thanks.

snbush67 · snbush67's Garage

Yes MFI will likely add a few hours to the cost.

I am assuming that you are trying to get more torque and horsepower from your engine, if so are there any limiting restrictions that you have. There are many great advisors here that can help you reach your goals

Bob Kontak · Bob Kontak's Garage

Quote:

Originally Posted by pors1968

What is CIS MFI or carb that make diff on price.

Not a pro but CIS would be easiest and would probably not need any adjustments at all.

Carbs a little adjustment - $

MFI a little adjustment - $$

HarryD · 03-30-2014, 01:36 PM

I would also think you will need a new MFI pump $pace Cam to match the new engine cam. More money.

Bob Kontak · Bob Kontak's Garage

Quote:

Originally Posted by HarryD

I would also think you will need a new MFI pump $pace Cam to match the new engine cam. More money.

I don't know squat about MFI except that you don't rely on vacuum, pressure, air sensors, barn doors, MAP sensors or MAF sensors to meter fuel. You have to "tell" the MFI what to deliver mechanically.

Trial and error with space cams sounds like you would be wise to invest in the time of an experienced pro, and they ain't that plentiful.

Just talking.

HarryD · 03-30-2014, 03:18 PM

Be aware that E cams make for a less "peaky" engine than S Cams by giving up a bit of hp at max revs. In fact many like the E engine setup for street during as it does not make you rev as much for power.

What your intent for the change?

If you are just driving on the street, you might want to keep things the way they are.

.PORSCHE. · 03-30-2014, 04:55 PM

Yup. I've made no decisions, at least not yet. My objective is simple: to get my engine running perfectly in all conditions.

In speaking with a factory-trained MFI expert, I learned that MFI systems are very sensitive to matching not only the MFI pump (or just the space cam) to the camshafts -- which I have already done-- but also to matching the intake and cylinder head ports to the camshafts and MFI pump. Everything must be matched to the system as designed. And if I were to match my heads to my camshaft and MFI pump, I'd also have to swap out my stacks and throttle bodies to match the intake ports on the 2.4E heads. In essence, I'd be building a 2.4E engine...

So, to have an 2.4E MFI pump with E cams on my engine is great, but it's difficult to perfect the setup when intake and exhaust components are mismatched. He said the factory engineered each system the way they did for a reason, and after a lot of research and trial and error. For me to mismatch components -- to try to somehow improve on the lavish R&D poured in by Porsche -- is a bit naive of me, and just like asking for an engine that won't run perfectly.

In sum, I'm thinking that maybe I'm better off returning this engine to all factory-designed 2.4S components. The peaky 2.4S engine is obviously wonderful (according to the market, at least). I'm told that If I want the car to run like. 2.4E, I might as well find myself a complete 2.4E motor and stick it into my chassis. I'm finding it hard to punch holes in that logic...

What are your thoughts?

HarryD · 03-30-2014, 05:04 PM

So for starters. You need to determine what you have. Has the car been converted to E spec? Which pump, cams, valves etc ?

Once you know the answer, you will know how to proceed.

.PORSCHE. · 03-30-2014, 06:27 PM

Totally 2.4S with the only exceptions being the E camshafts and 2.4E MFI pump. Unless I can buy into a different logic stream, I'll likely install my original 2.4S cams and 2.4S MFI pump. I'll have to rev the engine higher to find the torque and HP, and get stopped by the cops for racing the engine, but I know the engine will run perfectly, as designed,