Sam's build thread

[Sydneykid]

well I can say after driving the car around with the new timing gear on it that it is really crisp, boosts faster with a much more responsive bottom end and has lost nothing discernible at the top. How much can belts stretch? The old belt/original pulley appeared a smidge behind the cam timing mark before I removed it - can a belt stretch far enough in its normal service life to have the cam off a touch. Well with the new belt and CatCam pulley on, the pulley timing mark (which I transferred across) was if anything the width of the mark advanced. This would be most likely due to keyway freeplay in the new pulley (which wasnt as precise as the OEM) and a fresh tight belt yeah? Either way the car definitely feels better down low, undeniably so, so in the short term I'm happy.

I can't say for VW's but Skyline cam belts stretch enough to make around 1 to 2 degrees of cam timing difference, which occurs very early in their life and then they don't stretch much after that. So we usually check and adjust the cam timing after 1,000 k's or so. Might be worth checking yours around then.

Advancing the inlet camshaft timing 1 or 2 degrees is not a bad thing, could account for the increased mid range response. But advancing the exhaust camshaft timing, whilst OK at low rpm, is not so good as the rpm rises. If I had to guess I'd say 2,000 to 4,000 rpm it might be a tiny bit better, but I suspect that over 5,000 rpm it will be tiny bit worse. Which for what you use it for is probably not a bad result.

Cheers
Gary

[sambb]

ok cool that's interesting. yeah there's no way I'm off a tooth as I'd be getting codes straight away. Its just subtley advanced now and was subtely retarded before. Judging by the difference in the position of both cam pulleys timing marks (before and after) it could easily be 2 degrees advanced, which coincidentally seems to be a sweet spot people arrive at with adjustable pulleys on this engine. Like you said the midrange is what has gotten a boost (inadvertently) which isnt to say the top end feels weaker. I guess that's the strength of this engine with this turbo so its enhanced that strength a little more. I'd nearly pulled into the driveway at home and then had to do an important U-turn when I remembered I was out of beer and as I gave it a (fair) bit in second it ripped up the hill like a little terrier. This was exactly why I'd bothered doing the pulley in the first place but have kind of gotten the effect I was after without having to muck around on the dyno which is a nice win. Yeah I'll keep an eye on stretch that's for sure - just wish the tensioner could be accessed with the engine mount /bracket still attached! but I'll be pretty quick at that in the future now that I bothered to log all the socket sizes, torque specs, and have mounted a jacking point onto the block behind the sump for quick and easy enginee mount removal.

[metalhead]

That's no good, you're not allowed to be finding more hp!

I finally got a seat and harness mounted in my car last night, I'm trying to avoid any further complaints from scrutineers about my 40 year old factory seats and belts. Actually added a bit of weight to the car unfortunately, but will definitely hold me in place better.

Been meaning to reply to you about the 5th September, is it going to work for you?

[sambb]

I'm not I'm finding torque! That's cool re the seats. Cant wait till I can be properly seated/harnessed in with a rock solid steering wheel rather than my squishy thing. Makes a big difference. If you think you are on for that day then i'll move stuff around yeah. I like the idea of a mid weeker. Did I email you the Luff lap of Ludenham the other day - was a long night shift, who knows who I sent that to. It looks like a great little track with some good elevation change. We'll have to get along to there at some point too.
One of my 215/50/15 yokos just landed on the door step. 60 bucks for a week 43, 2016 with lots of tread isn't too bad. I'll just have to get a duro on it to check that its still usable though. Hopefully it will be then I'll just have to buy a fresh one off Levens to complete a front pair. weighs 9kg and is visibly a lot more tyre than even the 205's and makes the 195's that's are still on the Enkeis look like little pimples.

[seangti]

howdy, the timing belt (water pump and tensioner) on that car was done ~3yrs ago, gear all purchased through Imparts. Yeah I remember it driving noticeably nicer after doing the belt. The belts must stretch a bit. My mechanic has said it's quite common for people to report the car drives crisper after doing the belts...

[sambb]

Bit of an update. I have some stuff in the pipeline now for going to a race sump. Still wet sump, but as far as you can go down that path with full aluminium sheet construction (that is inclined to bend in a strike and not split/rupture like the cast ones), it has a lower height to avoid ground strikes yet an extra 0.7L capacity due to its rearward wing and it has a full gated oil pickup pen.

So the story with the sump is that this particular one doesn't have the relief cut in the base to house the OEM oil/level temp sensor. The good news is that these do not input at all into the engine ECU, they only go to the cluster/instruments where oil tempis not displayed and oil level is used to bring up the low oil level chime/light on the dash. The car can run without those no worries. I'm going to weld in a bung and fit a dedicated VDO oil temp sender and have a gauge mounted in the cabin. Oil level sensing is no big deal so that wont be used and i'll use an oil pressure sender in the port that currently houses the oil pressure switch that runs to the intruments too. I think an oil pressure gauge with an alarm is a far better method.
The other thing with this sump is that you don't need to run the OEM black plastic windage tray that goes under the crank. With these sumps, that is discarded and all the oil control duties are handled by the sump. I'll also have to shorten the stock turbo oil return pipe too but that's no biggy.
The big difference though is that this sump does not have the huge amount of cast material on it that butts up against the bellhousing. The OE sump has three tapped holes for the lower 3 bellhousing bolts to go into. I had a heart attack when I discovered this thinking that the sump is not going to work. But this sump is designed this way deliberately. The full house race engines usually run girdles that preclude the use of the bottom 3 belhhousing bolts anyway even if they go to a hybrid sump and they do just fine. As Issam (the designer at iABED industries - formerly INA industries) said to me - he's been brilliant by the way, advising me on fitment etc when I didn't even buy it off him, the gearbox is held in by 5 x M10 bolts and the sump bolts are mearly token - the sump is NOT a stressed member. So i'll most likely order the bellhousing cover plate (pictured) through him if postage from Canada isn't too bad or do a dummy fit up on my spare engine and make a template myself and cut something up at work. It'll fit like the example pics to cover the otherwise exposed flywheel.
Anyway that's the plan. Tracking an engine with 120,000km on it has its risks but I'm hoping that guaranteeing that the oil system is tip top it will stay as bullet proof as its been.

[simon k]

snazzy...

[sambb]

coolest F1 turbo era (the good turbo era) doco I've seen yet. Flares, lamb chops and lab coats. About how Renault pioneered their car - first turbo F1, first car with radials. My French is no good but the visuals are awesome.

YouTube

[Sydneykid]

So here's where I rain on your parade a little Sam.

The plastic windage tray is very important, it's not there only as a baffle, its function is to removed (scrape) oil off the crank as it rotates. High rpm crankshafts create a partial vacuum behind them as they spin, which the oil hangs in. That has both aerodynamic resistance (it increases the size of the partial vacuum) and it adds effective weight to the crankshaft (the reverse of a light flywheel). Plus it effectively reduces the amount of oil in the sump. The idea of the scraper is to (as the name suggests) scrape the oil trail off the crankshaft by disrupting the partial vacuum. For engines with a chain camshaft drive we also extend the scraper around the crankshaft sprocket so the chain doesn't carry oil upwards away from the sump.

This is an early VW engine scrapper from Ishihara Johnson;


Secondly the cast alloy sump is most definitely a block stress handling measure. They more rigidly tie the engine block at the main bearing journals. As you mentioned the full house race engines run a crank girdle as an upgrade from the cast alloy sump. I wouldn't be running an engine without one or the other.

That sump design has advantages but it also has disadvantages.

Cheers
Gary

[sambb]

Thanks Gary. RE the windage tray I was having the same thought. I'd found people who were running this sump with the OE windage tray still fitted - the sump doesn't preclude the use of the windage tray its just that you can run without. So yeah I was going to run with it because if the factory does then I will if I can basically.
RE the non stressed member bit I'm not surprised you thought that. I've been switching how I feel about that minute to minute. Part of me thinks if the girdled race engines (that don't seem to tie into the bellhousing) hang together then leaving my bellhousing 'hanging' would be fine. ie its not that the bellhousing gives strength to the block is it, and that an un girdled engine without the bottom 3 bolts would be weakened? or to put it another way if I thought that the engine would be ok it was more that the bellhousing would have more stress on its other bolts - more of an issue for the gearbox if anything. But it sounds like you think that it may compromise the block which I hadn't thought of. Hmmm
Don't get me wrong I'd love to use it but I'm very bad at putting things on the car that I don't have absolute faith in. I'm a worrier in case you haven't noticed. Thanks for the heads up. Ultimately its not going to be worth it. Thinking now I'll just go ahead with the oil cooler and get a few good gauges in there and monitor things that way.