mark kibort

No, not with the small US runners, but I thought this discussion was about the Ljet system not being able to support fuel for the larger flow components.
the intake is 1.6" vs 1.5" diameter. If i was going to guess about power loss on the runners alone, i would say, it would be negligible. after all, the smallest most restrictive part of the intake is the AFM, with only 4.14 square inches area.
the U is 7square inches area
the throttle body is 4.9 square inches
and the euro runners are 2.01 square inches area each x 2 is 4.02A
and US runners are 1.76 square inches area each x 2 or 3.52A 12% diff

RennPartsDirect

So how hard is it to swap in a complete 5 liter engine from an '86 into my '82? I've found one that the PO dropped close to $6K rebuilding it and replacing all of the valves and such. All I'd do is replace the belt and the rubber products and try to drop it in. My '82 has a small head gasket leak so it needs considerable work to be done if I go through the effort to repair it. Thoughts on that approach?

mark kibort

its pretty easy and straight forward if you have a good 5 liter short block to work with. are you doing it yourself? not hard work replacing bearings and pistons with rings. most of the stuff, your machine shop can do for pretty cheap... the entire thing shouldnt be very expensive at all.
my usual plan is:
re-ring
re-bearing
new head gasket
machine surface of heads... check for leaks in valves if heads are good

new water pump , timing belt etc....

but, what are you going to do for heads and intake?? all US stufff? might be worth getting the to end from someone for $2k or so used.

RennPartsDirect

I was going to use the entire engine from the '86. What top end are you referring to?

mark kibort

I might have missed that. sorry.... if you have the euro 86 stuff, then you are golden. just bolt it all on (with some very slight mods) and you are good to go. If that '86 is a US 4 valve.. then you are looking at a lot of work. the US 86, (as there is another thread about this) is a major amount of work to do the electronics to make it work. euro 86 engines make the euro 5 liter a possiblity its a pretty easy change and gives some great power when you are done mating the euro 86 with a US Ljet 80-84 engine electronics and fuel metering system

the slight mods include re-routing the cold start ciruit (easy as you can just port that to a port in the plennum. (fittings already there , just a simple hose and clamp) plug the back head ports of the euro heads (as the US ports are used for cold start by fuel going to intake ports ) the euro heads have ports going to exhaust ports. so, you just plug those with the same plugs as the heads have in the front of the heads on the timing belt side. (very easy). then the only other thing to do is a slight mod to the idle switch and WOT switch, which the euro TB has a more modular connection (also easy).

notch the pistons at the machine shop to match euro 86 specs (easy)

re-ring, rebearing and check the heads out and install.

Ducman82

if you swap in a later engine, 32v I'm guessing, how do you plan to control it? the early L-jet will not work.

mark kibort

you could adapt the Ljet to work , and that would be easy... the hard part is spark and timing.. how would you wire the ignition system.. it would be a big mess.

best thing to do is just do the proven suceessful way ... part euro 5 liter! just bolt the euro stuff on a 5 liter block

rcrone928

Mark. Euro top ends aren't falling off the shelf that I can see. Where can these be found?

mark kibort

I know... i stumbled upon my 20 years ago. they are out there, and its worth buying an entire euro engine if you can find one (85 to 86).

otherwise, best to find an entire car if you want a 5 liter 4 valver.

karl ruiter

The bigger Euro S valves can be part of a substantial performance improvement to a stock US motor. This is documented in an article from VW/Porsche that Greg did back when he was a young puppy. It has charts and graphs that show performance gains from big valves, exhaust, (and cams?). I think there might be an image of the article on here somewhere.

mark kibort

yep, eitherway, you need the bigger valves... euro is the easy way, putting larger valves in a 2 valve head is quite a job i would imagine!

Ducman82

i had to import mine from England .....

RennPartsDirect

I have the entire 1986 928 car to go along with the engine. I was going to swap everything over that needed to be swapped to make it work.

I should just put a supercharged Corvette engine in it and call it a day...

mark kibort

that would take this thread to off topic then. ....