8-71 NA marine diesels
8-71 NA marine diesels
(OP)
We are looking at purchasing a boat with a pair of 8-71 Naturals in it. We know in a few years we are going to repower it but right now we're gonna have to run these. do they make a turbocharger or supercharger kit for these motors? and if so which one provides the most power?





RE: 8-71 NA marine diesels
I cannot speak for the marine world but I do have that engine in my bus. The intake has a positive displacment supercharger/blower on the intake, it is a 2-stroke diesel. I have some info from people who put turbos on theirs and kept the boost low (6 psi & 12 psi). One had a waste gate and one did not. They used truck turbos and bought them relatively cheap. I have heard mention of being careful not to blow seals on blower. The 6V92 and 8V92 normally are turbocharged. They both claimed power increase was marginal at best but it didn't smoke in the mountains (less air). Since you are going to repower anyway, then it may be better to just tune those 2 since you probably won't be going to the mountians. If your interested respond and I'll post some partnumbers that they sent to me. Let us know what you do.
Sticking with the landyacht,
jomor
RE: 8-71 NA marine diesels
Blacksmith
RE: 8-71 NA marine diesels
I'm looking into the possibility of building small 2-stroke diesels with the poppet/port design and a small turbo. Any suggested websites or reading? What were the shortcomings of these 71 series 2-strokes (and other similar models?) Were they discontinued and why? Thanks a lot.
Wilksch is doing an aero diesel in this design. Interesting little engine. We've booked one of their first 160hp models for one of our Saab/MFI BA14 prototypes.
www.wilksch.com
cheers, derek
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RE: 8-71 NA marine diesels
In truck and bus the 8v-71 came in two popular itterations. 318hp was the most popular with 350hp produced with the turbocharger. The inline 6 came in 238hp and the less popular 260hp(I think it was 260) with the same situation with the higher hp being exhaust driven turbocharged.
Both the 318 and 238 were popular and well regarded. The most common problems were the constant oil leaks both from air box drains and from rear seals and the normal gasket leaks that come with age. The next most common problem that I recall was the jumper fuel lines either loosening or cracking and then leaking which would fill the crankcase with deisel fuel if not caught. Generaly they were both good engines. The turbo engines however had a major problem with camshafts and cam roller follower failures. It was determined that the combination of lubricating oil breakdown from turbo heat and or increased pressure on the exhaust lobes and rollers from opening the exhaust valves against the turbo pressure(The exhaust lobe or follower failed in 99% of the cases. I don't ever remember seeing an injector lobe bad.) Newer governor design with better fuel economy in the 92 series doomed the 71s.
RE: 8-71 NA marine diesels