stvracing

So as most know I have an '81 and I just bought an '80 Euro motor to swap into it. I will be doing a complete rebuild first. Now for the questions, stock to stock what is the horsepower difference between the two. Ive been told as much as 80 but wold like to hear from those knowledgable if this is factual or not. Also my car is stick and the Euro was auto, will this make a difference. I want drivability but would like to up the horespower to around 350. This car WILL be driven everyday. I do a lot of long distance trips about 300 miles each way. So what do you guys think?
TIA

IcemanG17

great upgrade....you are going from 220ish to 300+HP.....the EuroS CIS engine is quoted at 300hp-263torque....

350hp will be hard to get UNLESS you have a full race exhaust.....think headers, no cats and high flow exhaust

stvracing

Thanks Iceman, I planned on doing the exhaust that way. Im up in the air however on a supercharger kit.

stvracing

How about adding a good set of cams, nothing too radical. Any recomendations?

SanDiego928

Would this be possible in California? Less other mods.

SMTCapeCod

YEah....350 to the wheels is going to be a formidable goal. Flywheel, maybe not.
With the free flow exhaust and just going for max HP, well, it'll be a fairly small v8 tuned for best output up at 5500/6200 or higher...and not very effective down low.....depending on your bar for comparison

Forced induction is a key consideration. SC/no SC is probably a greater vehicle for total output than the distinction between US and Euro hard bits.

Best bets of the Euro are the intake, heads, cams.
But it is higher compression, too -which is not as conducive to forced induction.

Some of the supercharger suppliers post up a number of dyno charts across the different considerations..worth taking a look at what yields the best out of the box numbers if it is really an option. Short scoop is that IIRC SC US cars were actually putting down more power than SC Euro versions because the boost was constrained on the Euros, due to higher compression.

Throwing the Euro top end on the US shortblock might be a way to go if supercharging. 5.0 Even better, but still..

GlenL

My Euro S has been on the Dynojet at 286 RWHP. That's about 335 BHP. Mods:

'85 exhaust manifolds to stock dual, no cats exhaust
Timing advanced 4 degrees
Heads shaved to max
98mm '84 Euro pistons (higher CR and +0.1 liter)
A/F tuned for 12.5:1 at high RPMs and WOT
Right side cam degreed to stock

Every little bit helps.

atb

Tom M. and I did a similar swap, '83 Euro into a '79US.
You will notice a significant difference in power delivery. The US 4.5L is a real torquer, and has a lot of grunt down low and a healthy midrange. The 4.7L Euro is a screamer. It will feel softer on the bottom compared to the smaller motor, but revs freely to redline (and them some ).
This set up retained the stock '79 K-jet injection.
For the street I don't think you're going to find better cams, unless you can locate a set of '84-'86 Euro cams.
If Brian says you can see 350hp out of the euro motor, I wouldn't doubt it. But from my own experience I haven't seen it. Granted most of the Euro's I've seen have been very tired. The motor swap into the
'79 has yet to be dynoed, and that's probably the strongest Euro motor I've seen around these parts.

stvracing

Glen you mention about the right side cam being degreed to stock. Why is that, shouldnt both be the same in order to balance out the engine?

karl ruiter

Mixed opinions on how good idea boost is with a EuroS motor. You are already running a lot of compression and the amount of cam overlap with the S cams is said to make the boosted air just blow out the exhaust. Still some real gain, but not to the degree you would get with the us motor. If it were me I would do the following: 1) drop the EuroS motor in and see how you like it. Perhaps you will be satisfied at 300hp. 2) Consider dropping your EuroS top end on a 5.0 block. Anything else is going to be a lot more money and effort.

stvracing

So Karl you feel I should just bore to 5.0 and drop on the Euro top? Im looking to use what I have now really looking to go for another block.

karl ruiter

No, you cannot do the bore job very practically because of the Alumisil block. You would want to buy a used 5.0 block complete with pistons. There is a minor machining operation that is required to do the pistons tops. If you watch you can probably pick up a good 5.0 block for $500 or so, and the machining operation is minor. I think a full custom exhaust and all the other little tweeks will run you a lot more than that by the time you are done and be much less of a sure thing. This sort of motor is called a 'Hybrid' motor on this forum and is quite well documented.

Fabio421

If you decide to boost I have a set of low compression heads with the larger Euro sized valves and the big sodium filled valves on the exhaust side. I will sell these if interested but they are freshly rebuilt w/ zero miles. I built them for a boosted gasoline engine but have since changed my plans and I'm going with E85 so I don't need these low comp. heads. They should give you about 8.5:1 on a 4.5 liter and slightly higher on a 4.7 liter bottom end. As mentioned here, I wouldn't use the Euro cams if you boost.

Have fun with your project.

stvracing

Ive read a few builds but wont I run into an computer problem then with have larger bores and needing either a stand alone system or some ecus for the 5.0?

GlenL

The right side (1-4) cam tends to be a half tooth or so late compared to the left side cam. This showed in the compression numbers. Using a offset woodruf ley filed to fit the compression numbers were the closer on all holes. This showed there was a timing problem due to the belt length between the cams. Other people report the same problem on 16v engines.