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Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Sat Jan 15, 2022 1:59 pm
by 911hillclimber
Ill see if it fires using a safe advance setting and timing.
I'm sure Clewett will advise me.

The rollers are 25 mins away so will discuss it all with Ben.

Engine won't get much running in.
Few do and most get run hard from the start.
I've done this engine twice and there was no running in at all but the crank and barrels etc are good after stripping down.

This engine did 250 miles or so between rebuilds in 5 years.

Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Sat Jan 15, 2022 2:31 pm
by Cortina
RobFrost wrote:Presumably it needs a good run in before you can do those wise open throttle max rev runs on the rolling Road?

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............. very wise throttle ?? (I assume) :wink:

Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Sun Jan 16, 2022 4:34 pm
by neilbardsley
Doesn't it take a little running for the rings to seal? On my new engine I ran mineral for 1000 miles before switching to synthetic. I know you don't have that time but ...

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Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Sun Jan 16, 2022 6:02 pm
by 911hillclimber
Hill climb car dilemma.
Nowhere to do many miles, track use only etc.
Never bothered before, so will carry on as always.

Car does around 50 miles / year.

Today, spent hours checking the cam timing and putting those silly RSR rocker shaft seals on ( :roll: ) and setting the valve clearances, checked everything 5 times.
All pressure tensioner lines cleaned, new seals and in. all covers on.
This finishes the actual Porsche engine build, the rest is now plain sailing for the flat fan, the carbs and exhaust. Waiting for the next Big Step, the Clewett ignition system and all those wires.
Great fun...

No pics as it now looks a bit of a boring 3.2 Porsche flat 6.

Long way to go, 6 weeks left.

Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Sun Jan 16, 2022 6:08 pm
by RobFrost
I'd give it what you can at low revs and throttle, just to gently rub off any high spots of interference rather than ripping them away. Even a couple of hours would take off the worst bits.

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Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Sun Jan 16, 2022 6:15 pm
by KS
I think Graham has more than enough experience to know what he’s doing. My drag race engines barely had a chance to get run in. Not ideal if you’re after 100,000 miles between rebuilds, sure, but as Graham says, he’s after 50 miles between builds. I changed rod bearings after 30 passes - that equalled roughly 7 miles. Main bearings were checked after a season - maybe 80 passes, or 20 miles…

Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Sun Jan 16, 2022 6:25 pm
by Cortina
RobFrost wrote:I'd give it what you can at low revs and throttle, just to gently rub off any high spots of interference rather than ripping them away. Even a couple of hours would take off the worst bits.

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Please - NOT "low revs" on a new cam ( G will know that I assume) ... there is a "proven path" ?

Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Sun Jan 16, 2022 6:49 pm
by PeterK
Cortina wrote:
RobFrost wrote:I'd give it what you can at low revs and throttle, just to gently rub off any high spots of interference rather than ripping them away. Even a couple of hours would take off the worst bits.

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Please - NOT "low revs" on a new cam ( G will know that I assume) ... there is a "proven path" ?

Indeed, at least 20 minutes at 2k revs to bed in the cams.

Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Sun Jan 16, 2022 7:00 pm
by 911hillclimber
My plan I to break the engine in so to speak on the rollers, 20 mins will be a bit of a treat for my engines, but the new Cams might need some tlc.
I'll ask Kent about it.
20 mins on the rollers will be cheap, and give Ben a chance to see what it is doing.

After that and setting the ignition 'curve' on the Clewett, it will be balls out on the rollers.

If I have the time I will then check the head nuts and valve clearances, might take the engine out for that and onto the stand, only take a day that lot.
Fresh oil and filter and we are in business!

Championship kicks off in April at Prescott.

Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Thu Jan 20, 2022 1:04 pm
by 911hillclimber
A few more hours doing the simple stuff on this engine before the next challenge of the ignition system.

The oil lines are all in, simply cleaned and new alum alloy seal washers everywhere, nice and simple.
The custom made fan shroud next after a re-paint. This is a master class of thin aluminium sheet formed and rivetted to go around the engine, made by Crispin Manners I think about 25 years ago.
Followed by the DIY paper gaskets and insulators and finally the carbs.
Gave the carbs a good external clean down, been 5 years since they had some tlc. These are a sod to fit due to the two nuts on the middle cokes where they bolt to the heads, access is certainly limited, but all on using K nuts.

Next will be making the stands for the Clewett ignition coil packs which I intend to mount on the engine front cross beam a cut-n-shut 911 item.

No news from Clewett on delivery (story of USA parts for me) but could be next week..maybe.

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Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Thu Jan 20, 2022 1:24 pm
by andytat
Looking good Graham.
Have you ever thought about making a fibreglass fan shroud?
Andy

Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Thu Jan 20, 2022 2:54 pm
by neilbardsley
Have you ever considered not running a fan for your 45 second blast?

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Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Thu Jan 20, 2022 3:29 pm
by 911hillclimber
Andy, not much to be gained in weight, and the fit Crispin managed around everything is superb, must have taken ages.
Neil, not a chance!
The car sits ticking over for about 5 mins, maybe more before the off. Temp would be high to say the least!

Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Wed Jan 26, 2022 4:51 pm
by 911hillclimber
Clewett box arrives tomorrow, so have been detailing the engine to get the system wired-up.

The lower rocker covers need mods to get access to the extra plugs, so holes drilled, webs trimmed to allow the plug cap boots to fall flat and seal to the covers, additional support brackets added to keep the plug cap in the right position and a few other things.

When I first built this engine in 2009 (!) I added turbo bottom covers, bought from Andylightweight and one had been drilled for twin plugs, so I had a good template after checking dimensions.
This all took many hours, oh for a nice milling machine!

The Clewett comes with 2 x 3 coil packs that have to be mounted somewhere; some space was found and a custom light bracket made and bolted to the engine using holes already on the cam sprocket cover. I hope this will slightly hide away the modern look on the engine, will find out soon...

This is the last big task on this rebuild, but I'm not looking forward to all the wires and good routing. About 15 meters needed!

As famously quoted, "What can possibly go Wrong?"

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Re: 8000 rpm/300 bhp 3.2 rebuild

Posted: Fri Jan 28, 2022 5:09 pm
by 911hillclimber
After some faffin' about with FedEx, the Clewett box arrived. Heavy comes to mind!

Opened it all up to check everything is there, looked good.
Started to assemble the parts on the engine, looked good.
Fitted some looms that were ready terminated and worked out some routing to suit the car and how the current loom runs, looked good.
Crank wheel and sensor dropped into place once a small corner of the engine mount was trimmed off, looked good.

Wedding anniversary day today, but Mrs HC insisted we waited in to get this box grounded, so out in the Boxster tomorrow.
Forgotten what the 911 even looks like, been in storage for an age now, but all dry and warm.

Next step is the horrid bit, running all 12 plug leads to the plugs.

On the subject of plugs, added the spacer crush washers to space the Iridium plugs back a bit, gained 1mm, but feels more comfortable.
Gapped the plugs to 0.9mm gap, the correct gap for this level of tune.

Rapidly getting there unless the crimping tool fails.

Have to say, the Clewett product quality so far is 100% on the spot. :alien:

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