8000 rpm/300 bhp 3.2 rebuild

[neilbardsley]

Really twiddling my thumbs now...

The racing springs are correct with slight interference fit according to Kent Cams. Stops the springs from vibrating.
Have to use the titanium caps with the springs, stock steel ones will not fit, 12 caps here thanks to a ddk'r.
Installation length of the racing springs is 36mm. Not sure what tolerance is on that. (+/- 0.1mm?)
Stock installation length for both valves is 34.2/34.5mm

Not convinced the shims in the heads removed will give me 36mm so fingers crossed. Approx. 1.6mm to come out.

Heads should be back in 2 weeks time from m/c to twin plug, so can be built up while the long wait for pistons/rods continues.(update requested)

Might have to do the garden instead....

Just to und this correctly. The problem is that the rockers are expecting 34.5mm springs. If you use 36 then the other side of rocker, assuming the pivot is in the middle, will be 1.5mm too low? Long solution is to raise the rockers using shims but you are sure they get you 1.5mm? What is you look 1.5mm off the other size of the rocker? Would the angle be wrong?

Sent from my M2004J19C using Tapatalk

[911hillclimber]

There is nothing you can do with the rocker positions to height. The drop you think is there is not Neil. The rocker/top of valve/ cam profile all remains the same. The bottom spring seat that sits atop of the shims will be 'allowed' to drop closer to the head casting by the 1.5/1.6mm extra length.
All the bottom spring seats sit atop of a shim pack, generally 2mm of them, 4 shims as each is 0.5mm thick.

Thus, generally I will remove 3 shims from each valve bottom seat as you must have at least 1 shim (steel) to prevent wear to the alum head as all these parts shuffle around at 8000 rpm and less.

Problem will be if some valves only have 3 shims....
Not all the valves have 4 shims. If the seat /valve head shut face is deep then there will be more shims under the bottom spring seat and not all the valves sit the same in the 6 heads.

As the shims are 0.5mm that is the tolerance I have to play with, so EXACTLY 36mm is not possible with stock shims every position, there is a compromise somewhere.
If I had a surface grinder to hand, then things would be different.
I must check to see if thinner shims can be bought.

Had a busy day in the gaage. with no engine parts in sight I turned to the oil system and removed and cleaned the cooler and the huge dry sump tank.
Car was very dirty when they were removed, but everything good now.

It was with some trepidation I split the dry sump tank to see what was in the bottom after 5 years use. Swarf, bits of steel, shards of aluminium?

Nope, clean as a whistle, so chuffed.
This was a very good engine!

Dirty:



Dry sump apart:



Together again:



Cooler, cleaned and back in. So much dirt trapped in the cooling fins!

[neilbardsley]

I think we would all like to find oil pans that clean

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[andytat]

S cams have a spring height of 35mm intake and 35.5 exhaust so
it should be doable. As you mentioned there is a tolerance of plus or
minus 0.3mm so you should be able to get it there or there abouts.

Andy

[911hillclimber]

Hope so!
heads come back in 10 days from twin-plugging so I can build them up and see for sure.

Can you get thinner shims?

[911hillclimber]

finally, a bit of garage action.

Got my heads back from The Head Shop in Warrington who have machined them for twin plugs.
Great to deal with, promised 3 weeks and a good price, ready by 3 weeks at the same price, no surprises, price quoted inc VAT, what a refreshing change.

Bought a nice new valve lapping stick with supple rubber cups so grip these huge valves, and after clearing the carbon from the exhaust ports and re-fitting some studs (removed to access the area for machining) finally ground the valves on one head, set the small temporary springs to hold the valves tight and all fitted to the heads with shim-less assembly but the titanium top caps to measure the height for the racing springs.
This method works a treat, no fancy £110 tools, just 2 simple springs, £2.00 each.

With the tension on the two valves, 2 plugs in tight, inverted the head and filled the combustion chamber with white spirit to wait for leaks. One drop came free after 35 mins when a fellwe DDK'r arrived!

Drained the spirit off and measured the distance from the underside of the top cup and the lower spring seat.

For the springs I need close to 36mm on both valves, so by adding the right number of shims managed to get to 35.8 and 36.2mm. Can't get closer as the shims are in 0.5mm thickness only.

Springs in tomorrow and that will be one head done, 5 to go.

My main crank bearings and chains cleared Customs today, so they will be with me end of next week.
Another long wait then for the pistons and rods.

[Gary71]

Looking good Graham I quite enjoyed shimming the springs on mine, but then I’m sad like that!

[911hillclimber]

Thanks Gary, me too, but irritating I cant get the '36mm' datum closer in reality.
With shims only as 0.5mm it feels like +/- half a house brick.

Woke up this morning to a day to myself due to weather keeping us indoors ( )

Set about doing all 6 heads all ready to go on the engine, so once the smells have dispersed they will migrate to the 3rd bedroom...

Methodically did the following
Lap the valves, fit the temporary springs to both valves, fill combustion chamber to the top with white spirit, pause a few mins and check for leaks (none!)
Drain, measure the distance to fit springs with digital Vernier, calculate the shims needed to get close as possible to 36mm. Managed this exactly twice.

Strip, oil valve stem and insert, fit guide seal nice and snug using the tube sleeve provided to prevent lip seal damage, remove sleeve.

Fit springs and titanium top hats. The collets were a test, but the last of the 12 I did flew together
Using my motorcycle valve spring compressor is a darling, so light and easy, highly recommended.

[911hillclimber]

Photo test only.

[911hillclimber]

The Carrillo rods are in the UK with the UK agent. The pistons are an unknown so far, but I fear the worst. (later than expected)

I've asked for the rods to be sent now and the pistons later so I can at least build the crank and crank cases up ready while I wait.

I hope for an answer Monday.

The word 'hope' is used a lot in this part of the game which is a worry, BUT the rods are at least in the UK. Just got to get the agent to ship them!

The gearbox has been done in 4 days and back in the garage, so all I need is the rods and a promise on the pistons.

Question: Do JE own Wossner?

[Nine One One]

About Wössner Pistons

Wössner is part of the Wössner group which also includes FGM (Forging Group Monale) our Italian forging house for which we supply parts for notable companies such as Fiat, Ducati, Triumph just to name a few as well as Wössner NA, our distribution facility in Willoughby, Ohio.

Wössner pistons are still produced exclusively in Germany. The growing demand for high-performance forging pistons led to the founding of Wössner Italia Srl. in Monale. The pistons produced in Germany are also marketed there.


The origins of what we know today as JE Pistons can be traced back to 1912 and the Los Angeles foundry of William Jahns Sr. and his company W.H. Jahns. Employing the tagline, “Nothing but Pistons,” the W.H. Jahns company produced pistons and semi-finished pistons until 1948, when Jahns Sr. retired. Meanwhile, Jahns’ son, William “Uncle Bill” Jahns Jr., started and had been working on his company Jahns’ Racing Pistons since 1947. Shortly after, the business became Jahns’ Engineering Pistons, and was finally shortened to JE Pistons.

Through the following years, JE Pistons’ technology evolved, from mastering casting technology in the 60s to researching and implementing forging technology in the 70s. Numerical Controlled (NC) machines were introduced to manufacturing in the early 80s, which was quickly improved to the use of Computer Numerical Controlled (CNC) machines and a proprietary piston design and machining program in the mid-80s.

JE Pistons has continued to evolve their manufacturing processes, currently offering racing pistons either off the shelf or fully custom. JE pistons are all designed, forged, and machined in-house, allowing control over every step of the piston-making process. JE’s 7+ decades of experience in high-level racing has led to offering premium racing features, including full billet construction, EN plating, and purpose-designed coatings, to name a few.

[911hillclimber]

Thank you, most interesting.
I was told the other week JE and Wossner were the same company.
That made me wonder If the JE pistons on order and delivery looking shaky I could 'transfer' my JE order and get the Wossner instead. Design911 are also just offering a good discount on Wossner, bloody typical!!

I just might see them Xmas time, but I'm doubting it now and will put real pressure to get this engine sorted in time for the April kick-off.

[911hillclimber]

Time to get going on this little engine.

The debate about how to measure to 1 thou the stretch of the con rod bolts is resolved, I will use my digital verniers.
They give easy access and (in my hands) a repeatable result, despite my nerves.

I did 'make' a dti gauge like those sold all over the USA and used by the professionals, but I find them clumsy.

I've washed the crank, poked and washed the oilways with proper oil way brushes and carb/brake cleaner rattle can.
Dowsed the thing in WD40 after mounting it on the old flywheel.

The rod bolts need a 1/2" 12 point socket and I only have metric, too loose @ 13mm. A mate is bringing a selection of 1/2" for me to try later this week (ex Snap-On dealer).

The lower crank case has been cleaned 5 times using brake cleaner, oil drillings brushes and a scriber. All old sealant is off and all flushed out.

Black bin bags all cover the parts ready for an assembly. I expect to do the rods/crank Thursday and lay the crank/inter shaft and chains in the new mains after Xmas.

As to bonding the cases, that will be between Xmas and NY when I have the day clear in the garage.

The garage is getting as messy as Rob's!

[Nine One One]

Not sure what rod bolts you are using, but remember seeing this some time ago........

ARP 2000 series bolts they are super sensitive to corrosion and hydrogen embrittlement and you are not supposed to clean them with chlorinated solvents such as brake cleaner. Guess what I did - Yes, I gave them a good spray with brake cleaner!! You are even supposed to handle them wearing gloves because body sweat can be a problem.

[911hillclimber]

Yes, and the instructions say do not Magnaflux the rods with bolts installed.
Thanks though for the heads-up.
Bolts will be degreased with alcohol.