Have bought some turbo ones so slight upgrade....
But now have found out have a cracks in the head, anyone got a spare one ?
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| hotter cam and valve springs - confused.com https://forums.tipec.net/viewtopic.php?f=25&t=24309 |
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| Author: | jenko [ Tue Feb 25, 2020 10:29 pm ] |
| Post subject: | hotter cam and valve springs - confused.com |
Hi, Can someone help put my mind at rest? I am fitting this : https://www.augmentautomotive.co.uk/por ... xdQn5SQYaY to my 83 944. 2.5 8v. I spoke to the supplier at Augment who suggested stock valve springs will be fine however my mechanic has suggested stronger springs? After falling down an internet rabbit hole I am really in two minds if it needs stronger springs? Augment were pretty adamant that stock springs would be fine... It's a occasional track car and fast road, head is off and being re-skimmed and all seals and gaskets changed - should be okay? It's running Lindsey MAF and NA tune... What do you guys think? |
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| Author: | Waylander [ Tue Feb 25, 2020 11:18 pm ] |
| Post subject: | Re: hotter cam and valve springs - confused.com |
Just buy some new springs originals, as the ones you have will have lost a little power over 37 years and reduce the risk of breaking |
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| Author: | jenko [ Tue Feb 25, 2020 11:35 pm ] |
| Post subject: | Re: hotter cam and valve springs - confused.com |
after much digging I am opting for turbo valve springs..... will post the results:) |
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| Author: | sgl1966 [ Wed Feb 26, 2020 8:21 pm ] |
| Post subject: | Re: hotter cam and valve springs - confused.com |
I would follow Waylander's advice on new original . However I did do a 8v 2.7 head for a turbo using Isky Racing Springs for Nissan sohc part number 7005-8 following the lead from a gentleman on rennlist , very good price . They fit and are a stronger spring but never used the head so cant comment on use . |
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| Author: | GlennS [ Thu Feb 27, 2020 7:04 am ] |
| Post subject: | Re: hotter cam and valve springs - confused.com |
jenko wrote: It's a occasional track car and fast road, head is off and being re-skimmed and all seals and gaskets changed - should be okay? As long as you have fitted some extra bracing to the oil pickup or addressed the issue of sump baffles, yes. Otherwise... well, things will probably get a little unpleasant. |
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| Author: | tr7v8 [ Thu Feb 27, 2020 10:48 am ] |
| Post subject: | Re: hotter cam and valve springs - confused.com |
I'd assume being a performance cam that the lift & possibly ramps are more aggressive than standard. How much so dictates whether stronger valve springs are needed. Generally you'd be at doubles, but without looking it up pretty sure all 944s are. Stronger valve springs generally give a higher rev limit although this is also a function of the cam. Double valve springs are generally to protect against damaging harmonics. The springs should be as weak as possible, commensurate with controlling the valves. Strong valve springs waste power as well as harming the cam. If you can lighten the valve & retainers then that will help. I'd certainly use new springs on a rebuild, also carefully check the collets are still sharp edge, any that look suspect bin & replace. I've broken a few valve springs in engines & the result has varied from a slight misfire to carnage. |
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| Author: | jenko [ Thu Feb 27, 2020 9:43 pm ] |
| Post subject: | Re: hotter cam and valve springs - confused.com |
Have bought some turbo ones so slight upgrade.... But now have found out have a cracks in the head, anyone got a spare one ?
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