308 engine rebuild

I am hoping to attempt an engine rebuild on by GTB. I haven't done a full rebuild before on a Ferrari engine and will call on the help of experts for some aspects. I have carried out cambelt changes, full rebuild of carbs, general service items, clutch replacements etc.

The engine in question has leaking rings causing the engine to breath heavily. I am planning to remove the engine and strip it down. Then get a engine specialist to assess the block and crank and install new pistons and rings etc. Heads I will again get a specialist to reseat change valves if necessary.

I will then reassemble myself.

Is there any comments / advice before I embark on this project, special tools required etc. Is it sensible to attempt this?

 

You will need the various ringnut sockets for the drop gears and the cam drives, hill engineering is your best bet for quality tools

 

If you have not done a number of engine re-builds already learning on a 308 engine is maybe not the best of ideas. The engines are not terribly complicated but the cost of a mistake (even a little one) is very high so you are well advised to leave the re-build to someone with experience.

In your shoes I would do the following:

1. Remove and re-install the engine yourself. While the engine is being re-built do all of the 'while you're at it might as well' tasks both in the engine bay and externally on the engine. You can save a bundle doing this.

2. Give the engine to a good engine builder that has all of the tools required to do all of the machining, measuring, and assembly IN HOUSE. I cannot stress this enough. Having one shop do the machining while another finishes their work with final assembly opens up a whole can of worms when something goes wrong as each guy will always blame the other and it is you that gets screwed in the end. Have one shop do everything start to finish. Stripping the motor does not take long and the engine builder can learn a lot that will help him with the machining and final assembly.

Choose a shop with a good reputation but also with people that you can have a conversation with. Know it all Prima Donna's and guys who insist they are the best and everyone else is a hack should be avoided at all costs. It is the humble guys who let their work speak for them that ALWAYS deliver the best results.

3. With the engine apart re-build the heads and replace the sodium valves for stainless ones. It is not a huge expense and fresh heads are worth it at this stage.

4. With the engine out remember you will have the gearbox in your hands as it shares the bottom extremity of the engine casing. Here is a job for the ambitious DIY where you can disassemble and check the gearbox. Invariably a few bearings and synchros will need replacing but it is all something you can do yourself and it is hard to build the box wrong. In the end you can save a ton of money here and do the job yourself.

 

How many miles on the engine?

 

Very good points. And yep parts are starting to climb fast already. More then likely it's only going to need gaskets and seals, possibly bearings. But it also brings up the issue of does one do a simple refresh and move on or the complete inspect and measure every part and replace what's out of spec? infinite orders of magnitude difference in costs!

The bugger part is pulling the liners and replacing the 'O' rings. Yeah it's a real PITA job without a proper liner removal tool, but foolish not to if your stripping it down. The head studs bring up another problem, the studs available at the moment I wouldn't use. I'm fresh out of the aftermarket sets that were mfg a couple yrs back. Getting another order done will cost me a min of $10k!! that's not happening at the moment. So if the studs are good one is faced with a dilemma of pulling them or not! Why pull them? sometimes it's corrosion, sometimes it's due to needing to fix a warped block. It really comes down to condition and mileage.

It's doable by most anyone with competent knowledge of engines and the right tools. Sure there are quirks and particular ways of doing some things but it's not impossible. Mistakes though can get really expensive really fast! just something to keep in mind.

 

Bore it out and drop a 360 crank in there! It won't cost that much more and you will wake up laughing for the rest of your ownership days...I do!

 

Oh...that sounds interesting...what pistons and rods are you using?

 

You may also need a hed puller when I ripped my engine down I had big probs with one of the heads being stuck on the studs I had to make up a puller plate it was tough going even with the puller plate. Gud luk
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Since A-1 Technologies went out of business the only game left in town is ARP and they charge what the market will bear.

 

I've rebuilt other engines before doing a 308 engine. I would agree, it's a really bad motor to "find out" you did something wrong given the expense, but having said that, I was pretty meticulous and careful, and didn't rush the job, and the engine has proven to be a very strong and reliable track performer, and I got a lot of pride from that and a closer appreciation of Ferrari engineering. You didn't say how deep you've gotten in motors besides heavy service work.

I love the advice on how to interview the shop. Also, what machine shop you choose is key. Go by references, not price. When you clean up the sealing surfaces of the heads, remember that material is removed that cannot be put back. Like surgery. I recall the machine shop I used pulled the studs. By the way, this was ~20 years ago, and the machine shop bill was thousands. Then there was parts on top. This adventure is probably more expensive than others, because this motor was broken as opposed to worn. You should come out ahead given you won't need to replace some of the expensive bits. In my rebuild, the heads came off fairly easy, but there are some stories on F-chat that are incredible.

Also, the 360 mod does sound tempting. I'd like to know how easy tuning was for the new displacement?

Whatever you decide, I hope this goes well for you.

 

Your first challenge will likely be removing the heads. It can be a massively difficult job requiring a sophisticated puller, several days and a lot of penetrating oil. If you're not up for this you probably need to pass the job to someone else. Once in a while they come right off without much trouble. That has not often been my experience.

Once the heads are off you can evaluate the condition of the bores. You might get by with as little as a 0.010" overbore. This can likely be done without removing the studs or liners. Removing and reinstalling liners requires another special tool and should be avoided unless really necessary. Unless the studs get damaged removing the heads "hillbilly style" they will probably be fine right where they are.

My advice is to think things through first and avoid hammers and chisels. The last picture shows what someone else did just removing camshafts.
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Thanks guys I will get the engine out of the car and start to stripe it methodically. I don't know and engine builders in the UK who do there own machining. Serdi UK seems to do the majority of machining for southern garages

 

There are a couple of threads here with pretty complete how-to on dropping in a 360 crank. It's pretty involved if you really want to get the real benefits of doing the swap. Valves, pistons, cams, breathing issues etc.

 

Update on this, one head came straight off simply pulling it by hand, the other took a bit more work but came off with no real effort. Now I need to buy a ring socket to remove the transfer gear.

 

For the ring nut sockets best getting the Hill Engineering parts really well made and mount straight up to an electric impact gun

 

Thanks sp1der I presume once I have taken the gearbox off it is a case of an engine specialist measuring the bores / Pistons and telling me what needs doing. The condition and ease of disassembly suggests the engine was rebuild relatively recently so I am guessing the pistons have been incorrectly selected for the bores. The top of the bores look immaculate although one piston shows marks from a valve clash. The other Pistons look fresh

 

Would suggest anything that you are not confident with take to the nearest specialist, people like Rosneath or South Cerney engineering should be able to help with any measuring machining etc.

 

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Are these sodium filled valves? Can you tell by looking?

 

That exhaust valve does not look stock. I'm certain that's a Ferrea exhaust valve. Not sodium. I'd replace them anyway

 

I recall a few years back maybe 5-8 I read that the costs to rebuild a 308 engine was around $10-$15K. It would be interesting to see how much the cost has increased. Hopefully the OP is keeping tabs on his time but in this case it's the parts cost that would reflect price increases. As we all know our labor is cheap compared to dealer or professional mechanics costs. Good luck

 

Just pricing up for my rebuild as follows all GBP;
HC Pistons 1.1k wossner
Cams, springs retainers 3.5k (formula gt shim under)
Gasket set 0.6k
Bearings, fasteners etc 0.7k
Machining 2k (alternative is new liners at 120gbp each) inv valve seats
New valves 0.7k
Cleaning 0.3k (vapor blast)
Balancing 0.5k

The above assumes no major issues with decks/heads

 

Tap them on a vice and see if the break, they are that weak.

I would replace Brian, not worth the hassle of pulling the heads / engine out again if they fail!!

 

Why HC pistons?

 

Just the way I am going with mine as will have much more aggresive cams, probably little point for a standard engine but worth changing to modern pistons anyway With 3 rings.

 

My Dino engine and gearbox cost about £20k to rebuild by a reasonable priced engine builder, it was in a bad way.