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Crank Oil Seal Diameter Damage

roy33

By roy33,
in Engines & Forced Induction

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roy33

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hi, building up an rb30 in my back shed, and the crankshaft has been worn about ten thou by both oil seals, just wondering if people have used a sleeve or just put it back as is and if so did it leak, idealy i would like to put a sleeve on but this would involve machining the crank, i'm trying to keep it cheap as possible, as i've blown enough cash on recent cars as it is. also one of the cylinders has a small score in it, but below what seems to be the travel of the piston, (which i did of course removing the piston, damn!), would i need to get the block bored now or will it be ok?

cheers for any help,

troy.

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roy33 Collaborator

roy33

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also does anyone have the stock crank diameter tolerances, aswell as the cylinder bore diameter tolerances, just so i can check the block and crank before i put it back together. how much power can the stock rods handle, sorry i know its been covered but i can't find it.

roy33 Collaborator

roy33

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600hp, if the crank is badly scored, then you can fit a "speedy sleeve" without the need for any machining

ok, so the speedy sleeves have been used sucessfully by people building these engines? so i take it upgrading the rods to forgies wouldn't be worth doin for 350 kw atw car, just get the stockos treated

Adriano Grand Master

Adriano

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I would definately upgrade the rods for 350rwkw, thats about the safe limit of the stockers. By the time you fit ARP rod bolts, and get them sidepolished and shotpeened, big and little ends resized there isnt much difference in the cost.

R32 Driver Mentor

R32 Driver

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the cost difference between a 25 and 26 head

is around 600?

but 26 head goes straight on

25 head u need to weld/mod/tap

26 also has a forward facing plenum

26 has solid lifters

what car is it going in?

roy33 Collaborator

roy33

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the cost difference between a 25 and 26 head

is around 600?

but 26 head goes straight on

25 head u need to weld/mod/tap

26 also has a forward facing plenum

26 has solid lifters

what car is it going in?

the engine will be goin in my r33gtst, but i need the car to be running to get to work, so i'll have to purchase a head for the rb30, got qouted 350 for a 25det and 1200 for a 26, i know that the 25det has problems with the valve float under high power, but will chucking a set of 26 valve springs in it fix the problem? just wondering what peoples opions are about the two heads side by side, waying up the cost difference. for those that have welded the 25det head, what was the preferred method, the block is cast iron so just wondering what people have used, eg mig with cast iron wire etc. i'm trying to do as much as i can, with no engine building experience, but i'm a fitter and turner so i'm able to drill, tap, modify etc. i wouldn't have even tryed without these threads.

roy33 Collaborator

roy33

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To mod the rb25 head, i drill and tap the oil gallery and fit a m8 grubscrew in there, then get the head welded where the water gallery is close to the edge of the head gasket, i had a head welded and surface ground for $100.

ok, well that sounds pretty basic, 100bucks aint to bad either, looks like i'll probably be goin the 25 with 26 valve springs, i noticed that alot of people are choosing the 25de (na) heads over the 25 det heads, whats the reason 4 this, please excuse my ignorance but couldn't find anything

roy33 Collaborator

roy33

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i know its a long shot but does anyone have the approximate dimensions of the jun crank collar, gunna make one, can't see how they can jusify the 200 odd bucks they sell them for. any help would be greatly appreciated just after some rough sizes.

Edited by roy33

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