RennPartsDirect

I've read through the thread for 16V heads on a 5 liter block which is why I am asking this question:

Would installing clean, rebuilt 4.7 liter ROW heads onto a clean '82 4.5 liter block be beneficial in any way shape or form? My '82 has a very small head gasket water leak to the environment and if I'm going to put the time, energy, and money into repairing it I would be interested in gaining as much horsepower as possible in the process. I have a complete '83 euro 5 speed parts car at my disposal so I have access to the donor parts if it make sense to do such a swap.

Does anyone know if this will work? Has anyone done this before? What else would need to be modified to make this conversion work- anything on the block side? If this is completely asinine please don't hold back your thoughts. I'm not a motor guy so the collective group's experience is what I'm hoping to draw from here...

Steve

GregBBRD

With bigger ports and bigger camshafts, higher compression or more displacement is your friend.

Smaller displacement or less compression is counter productive. (4.5 liter USA engine, unfortunately, gives you both of these.)

If you have the complete car, why not use the entire long block from the Euro....and install the shorter ring and pinion transmission while you are at it?

RennPartsDirect

Greg-
Would I need to use the K-jetronic ignition and fuel delivery system or could I keep my existing systems and just replace the heads and block? Can you elaborate on why it'd be worth swapping out the transmission as well? Thanks for the response.

Also, you are the one that makes those wicked equal length exhaust manifolds, right? If so, do you have pricing on those?

Steve

GregBBRD

Your existing fuel system would have a tough time delivering enough fuel to keep that Euro engine happy. You'd do much better to use the CIS system off of the Euro.

Euro vehicles had a shorter ring and pinion....this "shortens" up the gears and allows the engine to get into the rpms where it works the best faster. The result is quicker acceleration.....and way more fun.

My complete stainless header and exhaust system for an early Euro engine runs $6200.

mark kibort

the fuel system should have no problems as we already did a 5 liter swap with the complete euro heads, cams and used the 4.5 CIS system. 320rwhp. good mixtures.

the transmission swap does shorten up the gears, but doesnt make them closer, so it really depends on what speed ranges you operate in whether they would make the experience any better. I like the euro gears for traffic when you are going really slow, as first is shorter and 2nd is easier to roll slowly in. but on the track, it would depend on the track , power you make and speeds you spend time at. contrary to the point of using the engine in the range where the engine makes power.... a stock 2.2 has a 1st gear that runs to 50mph........ so fun factor is in a range where you might want maximized acceleration , vs having to be in 2nd for 40 to 50mph bursts at a much lower HP range... its trade offs vs one another all the way up the speed range. ive race, owned and driven both.

I agree with greg though, putting all that work on a 4.5 , seems a little counter productive. find a 4.7 short block or 5 liter and make that work. when the engine is out, its only a day or two of simple work , to make it near brand new again.

GregBBRD

I thought the '82 USA cars were not CIS, but L-Jet. I doubted that the L-Jet injection will deliver enough fuel, so suggested him using the CIS from the Euro engine.

Thanks for the correction.

Kiln_Red

'82 US is L-jet. Either system will work, but I would favor CIS also.

123quattro

Stock US 82 system can keep up with the Euro parts. Only reason to get rid of it is because the injectors are old and the barb hoses are prone to burning down cars. You can bolt the Euro heads directly on top of your 4.5L bottom end. Dennis did that here in Detroit. I have the Euro heads on top of my totally stock US 4.7. It works as is.

mark kibort

I screwed that up too.. duahhh!! yes, even better still the US Ljet can handle it too. did that project as well. not even a rising rate fuel reg.. pinched off the return line of one of the fuel regs and it was enough to up the the pressure to keep 12:5:1. the cis from the US 78 cars work too! also proved on a 5 liter

RennPartsDirect

So did you notice any worthwhile performance improvements?

The Forgotten On

You can adjust the CO on the AFM in the L jet to enrich it. Just turn to the right to make it richer as stated in the WSM.

The L jet has 24 lb injectors so it should have no problems supplying enough fuel.

mark kibort

that is really only for changing mixture at idle. the over all WOT mixture is controlled by the flappy , and its dialed in pretty well. more displacement or volumetric eff, and the vain is pushed down relative and proportional to the air molecules hitting it. denser air, it moves more (and increases injector on time duration for more fuel) for the same air volume flow CFM. no need to mess with it... however, it can get near maxed out near the High RPM range for a 5 liter WITH the euro heads, cams, runners , TB etc. we are talking its TOTALLY capable to go from 177stock rwhp to near 290rwhp with no mods other than a rising rate fuel regulator, or a poor mans technique of pinching off one of the return lines of a stock regulator (there are two on the 82 US) ... thats over 100more HP with the stock Ljet system... pretty funny, when probst in his book said the Ljet was un adaptable to major changes in engine performance. just a small tweek and it performs well, safe and at only a cost of a power reduction vs its potential due to the little 2" x 1.5" square inlet (like a restictor plate! )

GregBBRD

Pretty amazing, with all of Bosch and Porsche's engineering and testing, that Porsche retained the CIS in the Euro engine, from 1980 to 1984, while the US cars used L-Jet.

I find getting the correct amount if fuel, all the way through the RPM and load range, extremely difficult with anything except virtually stock engines. Those "early 80s" 928s with L-Jet, even in completely stock trim, traditionally surged and had lean spots. I worked on getting rid of those running problems, when these cars were brand new.

I'll stick to my suggestion that if the OP has the correct fuel system for the Euro engine, he'd be a bunch better off to use it.

mark kibort

not that amazing greg... CIS is a cludge and is a big hammer for mixture control. Ljet was the first of the mass flow controlled systems that worked amazingly well, aside from the fact that to do it, the inlet was substantially smaller.
Greg, dont also forget the CIS was continued in europe because those engines were a big larger 4.7L, and were putting out 300hp vs the us 220 rated hp. (not great cams and big valve ports to boot) thas an 80hp difference!! no question to meet EPA requirements, the Ljet was used to not only lower the power, but to make a cleaner burning engine.
there were NO lean spots in the Ljet. ive tested quite a few of them with wide band analyzers on the dyno.... and the plug analysis confirmed that the cars ran clean, no detonation and put out good safe power. my Ljet 5.0 liter with just an increase of pressure to about 52psi ran perfect, decent power and was a stock Ljet system with only a rising rate fuel regulator as mods.
i even put on an injector duration meter and saw we were getting to the limits at the top RPM with the 5 liter and euro cams and heads /intake w headers.

interesting that if you believe what you read in probst book regarding FI systems, (a generally good book) he said that the Ljet was unacceptable to changes to make more power by using things like headers. in actuality, the system was perfectly adapted for these kind of changes and worked exceptionally well in all driving conditions. not only were all the changes incrementially safe as far as fuel ratios and driveability, the range was over 100hp of capability and maintained the stock mixtures without any changes at all. (fuel regs, just made it better)

should i post a few of the dyno runs with a baseline of 180rwhp to start? going to 200, 232, 246, 290rwhp progressively??

GregBBRD

Are you saying that you got 290rwhp with a 5.0 liter Euro engine running the small US intake runners?