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Hello all. I am new to this forum. This is my very first post.
The other day I saw a post from a guy wanting to do the same thing that I am considering doing: Putting a euro S top end from a 4.7 (heads, cam, intakes, throttle, etc). on a 1979 4.5 (US). This post will hopefully help the both of us.
Last month, I bought a 1980 Euro S parts car with the 4.7 and 5 speed trans still intact. Engine # M28/11. The idea was to put this motor and trans in my 1979 928 5 speed car, and replace the 4.5, which is in parts, and has been for 10 years. I would just use the 4.7 euro block that came with the 1980 928, but the bore is kind of scratched up. See below:
Motor looks like it was run hard,, too. Dirty outside, dirty oil, etc.
I checked on re-boring/re-coating the bores and it is WAY too expensive for my budget (like $1800.00). The 4.5 motor I have, on the other hand, is very clean with a nice, unscratched nikacil coating.
I am accessing my options here, but honestly, I would prefer to use a 4.7 block, since the combustion chamber of the 1980 euro s heads is around 97mm wide, same as the bore. It's just made to go together. Likewise, the combustion chamber for the 4.5 is about 95mm wide, same as the bore. Below is a picture of the euro s heads I just got, sitting on top of the 4.5 block. I plan to have the new euro heads rebuilt.
It looks to me that the head will fit ok. Not ideal though, cause the combustion chamber of the euro s head is a few mm wider than the 4.5 bore, which might cause some shrouding issues? Thoughts on this would be appreciated.
Also, below is a picture of a 1979 4.5 US piston versus a 1980 4.7 euro S piston. The valve reliefs on the 4.5 piston are shallower and smaller. I am not sure if they can be made both larger and deeper to accommodate the 45mm valves on the euro head, and the higher lift euro cam.
What do you guys think... should I just try and find another 4.7 block? If so, are the specs of the US 4.7 short blocks the same as the euro spec 4.7 engines? Are the pistons the same, with the same size and depth valve reliefs?
I am even considered building a 5.0 liter euro hybrid, but nervous that there is more involved than just fly cutting some pistons from an 85/86 5 liter block. What I mean are tuning issues, etc.
Lots of questions, I know. Any help is much appreciated.
Go with the 4.7 block you have. Those scratches aren't bad. They don't even go all the way down. You'll spend good money to cut the pistons and make them work. Get the extra 0.2l and simplify the work.
Was the Nikasil put on? Otherwise there is none. It's just the alusil block material that the pistons/rings touch.
I wouldn't waste the effort to do all of that work and still use the 4.5L. The stock 4.7L has no Nikasil, it's Alusil. That being said, you could send that block out for Nikasil coating and it would take care of those scratches. I haven't checked in awhile but it used to be around $800 to get a block Nikasil'd.
go with the 4.7 liter that came with all that good euro stuff. .... if you were so inclined, you could find a US 5 liter and put that on the bottom .. otherwises, re ring it new bearings, mains not needed , just rods and go have some fun.
edit: looks as though you split the block.. so new mains!
dont worry about those scratches they are fine..... just bolt it up and you are good.. PLus, the 4.5 valve reliefs are not really correct. you could fix it, but why. you got a good 4.7 there , is those are the only flaws. bearing, rings and headgasket and you are good to go! euro power!!
Thanks for all of the good advice. I didn't realize that the bores used alusil, not nikacil. I am glad to hear that the scratches aren't so bad. I haven't decided whether to go with a 5 liter hybrid or try and salvage the 4.7 ...here's why, and you all aren't going to believe this.
I bought this motor mostly for the euro top end, which is all there. Originally, euro S engine parts were all that I was looking for. It was to be and early Christmas..for me. Well, I ended up finding an 80 euro with most of the 4.7 motor intact, torque tube and 5 speed euro trans. I paid $1200 for all of it. The motor supposedly had just 80k miles on it.
Using a friends truck and trailer we drove 3 hours and rolled the stripped out 928 onto the trailer. It was in the guys yard, in the dirt..and it was hot outside. No time to check anything, just turn and burn back home. Man, was the car light. It rolled onto the trailer like a dream. That NEVER happens.
Back home, I found that the motor would hardly turn over, even with the plugs out. Right then I decided to go in for a closer look. First, I tore into that top end to remove the heads, like a kid in a candy store. I had to see those big valve'd euro beauties up close. Up until now I only saw them in pictures. It was a Kodiak moment. I slept with one euro head under my pillow that night. I cradled the other one.
Suffering from extreme Euro head mania, I don't remember much about the head gasket for banks 5-8. Seems it came out in pieces... I can't be sure, head bolts were flying and emotions were running high. I may have momentarily lost consciousness, I can't be sure. I know that the other gasket was fine.
That's when I saw the scratches and I became sober in just seconds. The hair began to raise on my hairy back. Somewhere off in the distance, alarm bells were going off. 80K miles and scratches? What The **** (also, BUMMER!)
Still puzzled, I removed the pan and found this treat within the 4.7's filthy belly:
It looks like this motor has seen a ton of water, coming through the top end, I suspect and seeping around the rings...down the rods. I think it had a blown head gasket, too.
Yet no water in the pan, just dirty oil. Fresh, dirty oil I suspect ! "It's the old fresh dirty oil in the rusty block trick.... Boys, they got me!
However, the rod bearings and journals look fine. I haven't remove the crank yet or split the block. I gotta save some of that fun for another day! Got to cherish it!
Anyhow, I just had to share this great story.
I can always use the rods out of my 4.5 of find another 4.7 US block, or go hybrid. No biggie.
All in all, I am not sore about the block. I feel like I made out good on the other parts. I just don't like being tricked. At least wait until October 31st to do that. (and let me put my Power Rangers costume on).
DUDE!!! ive been there ... you are speaking my language.. that block is old and tire.. probablby will work, but those pistons and rods are a mess. also will work (pistons at least... dont know about those rods..they look like they were recoverd from the titanic)
SO, you are into this stuff, right? just do it right. get a 5 liter block... find one in decent shape. dont even split the block for new mains. just re-ring it, rebearing it and knotch the pistons. (not that critical and very easy to do)
then, you have a 300rwhp beast that you will be proud of...
clean up the heads , intake as well.... .and then mount it up to your existing car.
more history here. why is that #2 piston in your hand so clean. why are the heads so clean. why is the block so dirty? what are you matching up here ... the euro 80 stuff , including block to go in the '79 chassis with CIS?
In the picture with the #2 piston next to the dirty 4.7 block, the clean piston is from my 4.5 US motor which I cleaned up years ago. I bought the 4.7, of course, to try and pick up 80 more hp. The purpose of the picture is to show the difference in the size of the valve reliefs of the 4.5 versus the euro 4.7 in case I or someone else was contemplating putting big valve euro head on the 4.5. Of course, I think one would have to re-cut the valve reliefs and make them both larger and deeper to clear the larger valved euro head and higher lift euro cam I got from the messed up 4.7 that's all messed up in the low end.
The block next to the clean #2 piston is the dirty 4.7 euro block. This was after I pressure washed it, as well. The 4.7 had some kind of clay-like mud wasp nests all over it. I mean like 10 of them. It was nasty. Now it's been upgraded to just "dirty". In the inside were the rare relics from the titanic. There are 8 such relics, all for sale to the highest bidder...lol. Only one wrist pin moves. The other 7 are really stiff and would make nice weapons, especially if thrown. The victim might also contract lock-jaw... another bonus.
Another picture shows the combustion chamber from the euro head on top of the the nice bore of my 4.5. The head had just been pressure washed and I wire brushed the combustion chamber a little to remove some of the extra carbon. I will eventually soda blast the head and make it nice, then take it to the machine shop to check for cracks and re-worked.
The purpose of the picture was to see just how much room there was between the bigger valves, and the bore. Also, how much the combustion chamber on the euro head protruded out past the bore. (like 2 mm, but more on one side than the other).
Last edited by Fresh; 10-28-2015 at 12:39 AM.
Reason: typo
So what you are saying is, I should NOT try and soda blast the pistons. Probably not even use scotchbrite on them. Is the iron coating just one the sides? Is the dome also coated? Thanks for the tip, I did not know this. I tend to try and make everything spotless (It's my OCD)
My 4.5 blew a head gasket within the first 6 months that I had the car. I decided to pull the motor versus trying to do the repair in the car. The head gasket I replaced was not original, either, the last owner replaced it once, too. This 4.7 looks like it also blew a head gasket. Dude, what is with these engines and head gaskets. I almost feel like spending $300 for head gaskets just so they don't blow one day.
Last edited by Fresh; 10-28-2015 at 12:59 AM.
Reason: typos
What did you do about the 4.5 pistons? I mean did you re-cut the valve reliefs? I assume that you used the euro S 4.7 cams? I am not too well versed with the CIS system, but doesn't the 4.7 euro S have a larger throttle (throttle body, or whatever you call it) than say the 4.5? Which one did you use? Which fuel distributor did you use, the 4.5 or the euro 4.7 ? What is the new compression ratio using the 48cc heads on there?
Man, sorry to ask so many questions, I am very curious. I must know EVERYTHING! LOL
Those Euro S pistons are hard to come by. I'd look to use the rods and wrist pins off the 4.5l and have the pistons re-bushed. I'd use some scotchbrite but don't scrub to a shine.
Going to the Cometic gaskets I'd leave for a future remediation. With the heads plane and the right torque method it'll seal up. Look for threads on torque versus angle for torquing the heads. The older engines call for a 3-torque approach and the later engines call for toque-angle-angle. "Best practice" has moved to use angles for all engines.
In my experience (and I've done a lot of head gaskets) the gasket problems are block and head warping, corrosion of the aluminum on the block and bad technique. If you're super-serious, pull all the studs and have the block decked as well as the heads.
10-26-2015, 10:14 AM
US 4.5 with Euro S top end
