im trying to find out what type of engine case to go for
im building a 2275cc and on the verge of buying a bubble case but
still cant decide can anyone help me out at the momment i have my 94mm pistons, 82mm stroker crank, straight cut cams gears 125 scat rockers and a few
other parts
any help much appreciated
cheers jamie
I am currently building my second engine using a CB aluminium case, no issues at all, a better foundation than the mag case. you can get it in a lot of different configerations to suit your current parts.
I'm in the middle of using a CB case here too. so far no issues apart from one stud that broke when only cranked up to half the specified torque. I
rekon it already had a fracture in the stud anyways judging by the cross section. Thats the only compliant, but it was one and i had a spare so no
biggy. Just a pain in the case having to part the case, clean the sealer and restart again.
Alum is heavier, and runs hotter (only issue). CB cases in stock form already have substantial clearancing for stroker cranks too (unlike magnesium
where you'll have to machine it), i don't know if its enough to clear for a 82mm crank though (you'll have to check), but its saving you from
having to clearance it like the magnesium. CB performance also offer in there alum cases drilled and tapped for full flow and can in a big range of
different bore deck heights to prevent the need for mass loads of barrel shims which you'll need to resolve given your stroke you want to use.
If you still feel need for magnesium, dual relief 1600 is what you are after. Ensure it isn't too old / had a long service life due to fatigue and
eventual cracking. Best way to 'estimate' that is to measure the main bearing journals of the case to see how oversized it is. Therefore you can
judge how many line bores it has (IE: how many times its been rebuild already in a past life). Have a chat to Mr. Matt Berry
wheres the best place to buy a cb case cause ive been quoted 1500-1700 is there anyone that sells them cheaper? i want to go with all brand new parts so i know nothing is second hand and that less will go wrong with it
I bought it from CB performance on their website. Was the cheapest.
i think it was $900 for case and a couple hundred for postage. It got held up at customs for tax purposes, given they wanted 10% for imported goods of
value greater than $1000. They had an option on the letter I recieved from then (stating that they were withholding it until tax was paid), that if i
felt the item isn't worth greater than $1000 and I show the invoice to prove, i could avoid it and they would release it for delivery.
I sent Aust customs the invoice, stating it was worth $900 or so, and they released it with no tax.
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http://forums.aussieveedubbers.com/viewtopic.php?tid=104849
When I was 'weighing up' the difference betwen the 2 cases, Rod Penrose pointed out the weight difference. The last thing I needed was another 12 or so kilos hanging out the back, so it was the magnesium case for me. So far, so good. 2276, by the way.
The material in the aluminium case is a lot more durable than magnesium and will last longer , they also come pre machined to very good tolerances, seen to many mag cases crack and the quality of the new mag cases are not as good as they used to be.
Mag cases may crack but how many of those cracked cases were caused by other factors like poor cooling systems and bad tunes?You can't buy an ally replacement case for your 73RSR Porsche they run a magnesium case.Also aftef market stud kits are not a 100% correct replacement for og german and nuts which have diffrent expansion rates which all have to work togeather to have a happy engine.IMO a happy hot street VW uses as many VW parts as possible including thermostat flaps in a german fan shroud with german barrel covers etc.I'd rather have a reco'd $250 mag case and $750 worth of reco'd german tin than a $1000 ally case and chinese tin,but thats me and im crazy ask anyone.
The case for the porsche is magnesium because it is a race car and weight matters, regular replacement of it would be normal. problem with the mag case is it ages and becomes brittle, there would be no way i would use a second hand magnesium case on a new performance engine, i run both case and have good resalts with both, studs are a different story, the case studs have a job to do, that is provide the clamping force to hold the case together, head studs are something else, i would also dispute they run hotter, i have seen no controlled tests that proved that, my 2275 in my ghia with 10.8 to 1 compression has no issues with overheatiing, both oil temp and cylinder head temps run fine.
thanks for everyones help im gonna go for a cb case ive realised my engine will cost me alot more then i though and its gonna be a bigger engine that
i thought also but it doesnt bother me.
i want a strong engine and sound like a cb case will be the go.
The aluminium case is designed for the job and the mag case has to be modified to do the job when the factory only intended it for a 1600.
go the ally case if you want a bullet proof motor
yeah i was going to get a cb ally case craig cant wait to be at the point were im putting my engine together and going to start it for the first time 8 months is my goal
I am currently building a 2054 on a CB case
Ditto! 2054cc on CB
Personally the attraction wasn't so much the material, but the 100% zero km brand new case, with no extra machining costs at all for 94mm, clearanced
for stroker crank, tapped for full flow, strengthened behind cyl 3 etc.
Magnesium cases would attract all that extra machining, so for cost effectiveness, i went alum (with no compromise on reliability etc.)
As far as the Auto Linea after market cases go, the CB or Scat are the best. They seem to be machined in different places but both I've used with
good results, as opposed to the Empi ally cases, these are still Auto Linea (the foundary that casts them) but I have seen problems with a few cases
so would not recommend them.
Personally, I do prefer the light weight of the mag case and the way everything then fits together but horses for courses.
Maybe a little off topic but, how does a type 4 case compare to the ally case? Is one a lot better than the other to use when building up a
performance motor?
Yogie
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