What would people like written.

campbellju

Moderators
Staff member
Diff's, what mods or tricks are there to improve the performance of the standard ones? What options are best and why (response, locking effect)

I have a good general idea but it's something I'd like to refine my understanding
 

PobodY

Moderators
Staff member
That's a good idea Jim. - I'd be interested to know if there's anything a "home mechanic" can do; maybe what oils are/aren't worth using to get the most out of the standard components you've got.
I figure dropping the oils and refilling is easy enough, but re-shimming a differential or swapping the internals is probably beyond me.
 
Who has the money? Rockers will be an issue at that so you are then onto vvl heads....basically you would need copper beryllium valve seats,stainless one piece valves,90lb valve springs and lightweight retainers, good light weight rods like carillo,an 82mm stroke crank (steel sr18 one),89mm cp or similar pistons,cosworth 90mm gasket,decent liners, everything dynamically balanced,stock head bolts,arp l19 rod bolts,arp main studs, crank scraper, dry sump kit, and a good machinest to do the bits to exact tolerances , 10,000rpm and reliable.
A dude in The US was running 10,000rpm on a pretty stock VE head (springs and retainers). The stock oil pump was the weakest link.

There are a few guys in europe (greece and eastern europe are you best bet) that will cut copper beryllium valve seats if you feel so inclined.
 

The Doc

Moderators
Staff member
Was it the oil pump or was it a flexing crank that caused the failure? As that will knock out bearings as well, ideal would be to use a dry sump if using that rev ceiling as one small amount of aireation in the oil will cause huge huge failures.
 

red reading

Active Member
As above, I have heard of people revving stock gtir engines to 8200 rpm with no short term issues....as for long term we know the answers on that, only reason I specked what I did was for longevity of the engine and that with long rods and short stroke you will get longer dwell time at TDC for a better burn at high rpm and still have reasonable mean piston speeds as well, btcc use to do the same thing with the sr20 engine and used the gtir block with 82mm stroke and 88mm bore,....they made 300bhp on a n/a setup with no rocker trouble and no vvl heads too.
 
Completely agree Danny, if I was asked to spec an engine for 10k rpm I would end up with a very similar spec to the one you listed. I just thought it was interesting that someone decided to push a pretty stock SR20VET that far.

Here's the pictures of the damage: http://www.sr20-forum.com/turbo/45952-new-setup-build-updated-5-25-12-723whp-32.html I'll let you guys diagnose the failure mode, the owner suggested the oil pump was at fault but it could well have been crank flex.
 

watoga

Member
step by step "how to" rebuild a solid bottom end (include basic tools, parts that should be replaced, tips and tricks)
Yes, I agree that this would be very useful indeed. Also, I would be grateful for some information on when to use a head torquing plate during an engine rebuild. These head torque plates can be found (for example) here:

HEAD TORQUE PLATE

I know they should be used during the honing process, but many also seem to recommend using them when measuring clearances, etc., but how important is this for a decent rebuild? I'd be interested to hear your thoughts......

Cheers,
Dave
 

red reading

Active Member
Right, when I get back from holiday I will be doing the write ups that have been suggested , will prob start with bottom end engine builds, whys, what's and torque plates and when you need stuff, then head work and so on. It will all be posted up once the mods have ok everything and stuff.

Just a quick answer to the torque plate thing, yes they are a good idea if you can replicate the plate to behave exactly like a cylinder head as bore dimension do change quite drastically on some engines when the head is bolted down, do you really need it for a up to 500hp road engine gtir...no tbh as you are not searching for perfection.....if you wanted that you would also need to measure the bores when the engine is at its design operating temps ala formula 1 etc
 

watoga

Member
Just a quick answer to the torque plate thing, yes they are a good idea if you can replicate the plate to behave exactly like a cylinder head as bore dimension do change quite drastically on some engines when the head is bolted down, do you really need it for a up to 500hp road engine gtir...no tbh as you are not searching for perfection.....if you wanted that you would also need to measure the bores when the engine is at its design operating temps ala formula 1 etc
That's what I thought, but it's nice to hear feedback from someone who actually knows what they're doing! :-D I am looking forward to reading your write-ups, they should be very helpful indeed!

Many thanks,
Dave
 

stevepudney

GTiROC CHAIRMAN
Staff member
Right, when I get back from holiday I will be doing the write ups that have been suggested , will prob start with bottom end engine builds, whys, what's and torque plates and when you need stuff, then head work and so on. It will all be posted up once the mods have ok everything and stuff.
That'll be great Dan, look forward to reading it.
 
W

webadmin

Guest
Buyers guide would be great too. I dont think we have one of them.
 

shroom

Active Member
Would be quite easy...

Dont buy one



In all seriousness it would be good, the amount of people whp buy cars with forged engines etc later to find they dont is daft,
 

red reading

Active Member
Buyers guide would be great too. I dont think we have one of them.
Ok I think that is a good idea, especially after seeing the recent stories of cars blowing up etc after purchase and the others who have bought forged piston engined cars and then found that it is standard etc, I will eventually do a write up on gearboxes and diffs as I have good knowledge of those and the tell tales as what is what and guides on how to tell certain things like is it stock or aftermarket.
 
W

webadmin

Guest
lol shcroom.

Lots of work for red reading to do there but all great stuff.

:-D
 
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