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Tech Spam thread - because 1/4" BSP gets 5 hand spans to the jiggawatt


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1 hour ago, ajg193 said:

Does anyone on here know much about valve clearances and ramps on flat tappet, solid lifter cams?

 

For example, aftermarket camshaft profile calls for 0.3 mm inlet clearance and 0.35 mm exhaust clearance

 

Factory profile specifies 0.2 inlet and 0.3 exhaust

Will setting the aftermarket cam to 0.275 inlet and 0.325 exhaust in order to reduce noise cause too many problems long term?

The duration for the cam is like 180 or 190 deg at 0.05", with advertised duration of around 260 deg. Would this make the ramps about 35-40 deg duration?
 

most will allow .05 either way.  so .025 will still be well within spec.    I could be completely wrong,  but would assume at least part of the reason  aftermarket cams call for bigger clearance. Is said engine with the cam swap is a whole lot more likely to be raped within an inch of its life than a stock engine.  so bigger clearance to take up the thermal expansion.

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All fair enough.

I inspected the valve clearances, about 4 of them tightened up by 1 thou, one loosened by a couple of thou and the rest were stable.

 

Other side of it is how does one actually set the valve clearances accurately on a hot engine? The engine cools down so rapidly that by the time you get to the last ones the engine has dropped about 40 degrees.

 

What I do, I don't know how legit it is though, is I set the clearances cold and do it about 0.07 mm / 3 thou tighter than the hot temperature. This is how the Toyota manual specifies it for when assembling engine. I've checked the clearances hot afterwards and they were pretty much on the money immediately after engine shutdown. Another thing to note is that it takes about 10 minutes to get to the rockers as the EFI plenum and intake ducting need to be removed

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2 minutes ago, kpr said:

most will allow .05 either way.  so .025 will still be well within spec.    I could be completely wrong,  but would assume at least part of the reason  aftermarket cams call for bigger clearance. Is said engine with the cam swap is a whole lot more likely to be raped within an inch of its life than a stock engine.  so bigger clearance to take up the thermal expansion.

They guy who ground the cam reckons run a little tighter than cam card to shut it up and get a little more top end or run as loose as I can tolerate the noise if I want more bottom end. I'll see how it goes with 1 thou tighter. As it was I hadn't lost any power at all below 3000 rpm compared to factory cam so I could afford to lose a couple of percent.

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8 hours ago, kpr said:

doubt there would be any measurable difference in power.

With the other cam I had in it I lost a tonne of power on the bottom end by tightening up the valves a little bit. I don't think it did too much to the top end though, was too afraid to rev it past 7000

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 I am trying to help someone with a distributor for a 351 Cleveland I am told the Australian 351 and 302 Cleveland has a slightly different drive end to the USA Cleveland they will interchange but one will be lose in the drive slot, can some one confirm this?

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1 hour ago, SOHC said:

 I am trying to help someone with a distributor for a 351 Cleveland I am told the Australian 351 and 302 Cleveland has a slightly different drive end to the USA Cleveland they will interchange but one will be lose in the drive slot, can some one confirm this?

https://www.fordforums.com/threads/identifying-aussie-blocks.150135/

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apparently the size is 

 bore diameter for the dizzy pilot in the block is 0.5160" to 0.5175"... for all US blocks and Aussie blocks up until the day they changed the size of the hole.

he Aussie Black Block which was in 1979 XD Falcons on had the factory Electronic Distributor, which has .490 where it goes in the block and also up higher where the gear runs is .490

 

If it is a black block it will be 12mm, earlier blocks 1/2 inch.

 

changed to smaller size part way through 1979

 

 

and you can ream out the small one to fit a use distributor, otherwise need bushings

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Gluing in windows. At some point i'm looking to fit the front windscreen and rear 1/4 windows back into my car. 

Selleys do a silicone sealant which i'm looking at for the windscreen (was recommended). https://www.supercheapauto.co.nz/p/selleys-selleys-autofix---windscreen-sealant-310g/219451.html?gclid=EAIaIQobChMI17C_3qTA7gIVDhwrCh3a6AU-EAUYASABEgK0-PD_BwE&gclsrc=aw.ds&fbclid=IwAR1Ym3KlDfOmfBYExTcBO4Ntf82yJDLDoSq6_8y4HNMWG_cadbNG8Zn5sp0

However, the rear 1/4 windows looked to be held in by mastic of some description. Is there any reason to not seal these in with the same product? Having removed the mastic stuff, I don't think it would allow for any more movement than the rubber silicon product. So just thought i'd see if there is a reason I shouldn't just use the same product everywhere. I plan to run a bead of sealant around the frame edge as it previously trapped water in the gap and rusted out the whole frame.

 

tl;dr any reason not to glue in rear 1/4 windows with sealant rather than mastic stuff?

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26 minutes ago, Bling said:

Gluing in windows. At some point i'm looking to fit the front windscreen and rear 1/4 windows back into my car. 

Selleys do a silicone sealant which i'm looking at for the windscreen (was recommended). https://www.supercheapauto.co.nz/p/selleys-selleys-autofix---windscreen-sealant-310g/219451.html?gclid=EAIaIQobChMI17C_3qTA7gIVDhwrCh3a6AU-EAUYASABEgK0-PD_BwE&gclsrc=aw.ds&fbclid=IwAR1Ym3KlDfOmfBYExTcBO4Ntf82yJDLDoSq6_8y4HNMWG_cadbNG8Zn5sp0

However, the rear 1/4 windows looked to be held in by mastic of some description. Is there any reason to not seal these in with the same product? Having removed the mastic stuff, I don't think it would allow for any more movement than the rubber silicon product. So just thought i'd see if there is a reason I shouldn't just use the same product everywhere. I plan to run a bead of sealant around the frame edge as it previously trapped water in the gap and rusted out the whole frame.

 

tl;dr any reason not to glue in rear 1/4 windows with sealant rather than mastic stuff?

Polyurethane windscreen glue is good, it’s a little harder than silicon, mastic is for old rubber seals 

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Sweet thanks team. Will look into the sealant options then. Getting a pro in to do it is an option, trying to organise that will just be a punch in the dick though. So if I can DIY it, I will. Rear windows still have the foam rubber strip mostly in place for keeping the seal in check. So i'll likely measure it up and clean the windows 100% before adding back a new seal to goo against.

Something like this should do the trick https://www.wyatt.co.nz/shop/REPAIR/ADHESIVES+%26+SEALERS/Pro+Form+Urethane+Sealer+Adhesive%3Fsku=PF1812.html But will also enquire about getting it pro done. But then i'll probably want a new screen put in and it snowballs.

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My mk4 zyepher zodiac gearbox jumped out of 2nd twice wile engine braking on a super steep hill, what would cause this? last time it was jumping out of 3rd because of the shifter rod hitting the floor. 

 

I wonder if the extra engine braking was shaking shaking it out?

 

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