Extracting More Power From E88.

[Gav240z]

Ok so I thought I should ask you guys what I could do to improve my engine set up.

I have recently aquired a engine head (E88 Casting). It's basically got the guts of a N42 valves, had a fair amount spent on porting, 76 degree camshaft profile.

It will sit on a f54 block most likely dished pistons will check when i put her back together. roughly 10:1 compression. I dunno how to check really I get 180psi across all of cylinders with the current e88 f54 combo on the car.

Anyway to my point I'm told it's got roughly 120rwkw. Now that's fine and dandy but I reakon I want more power. I was thinking 3 way valve job, maybe match the intake manifold to the head. Etc.. but what else can i do to extract more from it?

My requirements are to keep it street happy while not being over fussed about it being a bit wild infact I really don't mind.

I don't want to change carbs yet I wanna stick with the SU's because of my budget and I think later I'll try something like Weber efi set up.

For now though it's gonna be the SU's.

Car already has electronic ignition etc..

Any idea people .

[Mr Camouflage]

F54, thats a L28 right?

You wont get anywhere near 10:1 compression with dished pistons.

I recon (well, the L6 engine builder calculator recons) you have closer to 8.28:1 with that combination.

putting flat top pistons will boost it to 9.8:1

1mm head gasket or overbore .040 (with standard gasket) will put the compression just over 10:1

Of course that's based on the L6 engine builder, which might not be entirely accurate, or could be very accurate. I wouldn't know.

[JMT240KGTR]

Gav,

180 psi puts it around the high 9-low 10's C/R mark, which is pretty good for street. You can shave the head .030" (max recommended before shims req'd IF you go by the book!). Shaving the head .030" should increase C/R more than half a point ie .5+, so if you think you've got 10:1, this will up it around the 10.5+ mark. Bear in mind your SU's may need looking at, the engine will be thirstier although you are currently at the

10:1 mark so I assume the SU's are running well and should be able to cope with a little increase in fuel/air delivery.

That being said if you really want noticeable power increases at this stage with a C/R of 10+:1, start looking around for Dellortos or Webers, you won't go back to SU unless you find them expensive and a pain in the @#$%! Or have your SU's re-jetted and modified (throats bored), even cheaper alternative and when done properly, perform almost as good as triples.

A little advance in timing is nice, try that. What diff ratio is in your Z? A 3.9 or higher ratio will give life to a sometimes sluggish starter but good top end engine.

The mods you mentioned ie port matching, 3 way valve job etc are mods pretty much confined to much higher comp/turbo engines, gains from these mod's will be much more noticeable than on a street car; although people do it for the street so the choice is yours.

If I were you with the C/R you currently have, I'd take the SU's off, wrap them up and put aside, and instead of spending money on a valve job and port matching, keep the money for triple 45mm carbs. Gains from this compared to what you were thinking of will be much, much greater and your Z will fly.

Mate I SWAPPED my set of triple 45DHLA Dellortos for a set of 240SU's and I tell you what I bloody regret it; I was an idiot!!

Cheers. :classic:

[Gav240z]

You could be right Mr C, I haven't peeled open the engine to see if there dished or Flat Tops.

The story is I have the current E88 set up with f54 block , it's almost identical to the engine head I mentioned above except the new one I bought has the larger 76 degree cam.

Now I would have just thrown a bigger cam into the current one but it was cheaper to buy this one as it was recently rebuilt and the old ones valve stem seals were worn etc.. I also had a couple of people clarify this engine as a real goer so I got excited about that of course .

At the moment the car does ping a bit on WOT I think the timing could be a bit better but better yet the su's need adjustment they need bigger needles and seats I think. The reason I wanted to stay with the SU's is that I have a mate with a p90 head f54 block diesel crank and SU's and he's running low 13's. My goal was to get close to what he is running on SU's.

However if everyone feels tripples are the way to go I should consider it i guess the PO of my car had a set of dellortos on the car and slapped the su's on when he sold it. He said he would sell them to me but I think I like the webber carbs.

I plan on getting her on a dyno after it's all set and running also.

The reason I liked the su's was because I knew the carb and after seeing my friends Z go figured there was no need for tripples.

Thanks for the input anyway guys, seems like theres not alot more than can be done to it. How about if i made it a bit on the wild side?

[Ben]

I'm not convinced that 180psi is anywhere near 10:1 compression - A fresh FJ20E will get around the 220-mark and the CR is in the low 9's. My FJ20ET was around 180 & the CR is ~7.5:1.

Gav, it sounds like whatever you do, you need to get your ignition re-curved to make the best of your setup.

The tripples will give you more tuning flexibility than the SU's, but you will also gain more complexity at the same time.

Having said that, I know that you can produce over 150rwkW out of SU's, but boy do they have to be heavily modified....

Mind you that was on an L24 turning around 7500rpm & lifiting the front wheels while attached to the dynopack dyno!

A set of tripples, re-curved ignition & a shorter diff will yield quite respectable gains.

120rwkW is nothing to be scoffed at - if it's true you should be able to run a low14/high 13 already.

Do you have a dyno sheet (with AFR vs power/rpm)?

[Tiburon]

Gav, the pistons would have to be flat tops in order to get 10:1, given this, I would seriously consoder going with Total seal rings, these cut down on blowby and are stout rings thus giving you the power you're supposed to get.

I would recommend getting the piston skirt dry film lubricant coated

I would also get the piston crown coated with thermal barrier coating so the heat doesn't bleed through the piston....the better you control thermal energy in an engine, the more efficient it will be.

port the intake and have it heat dispersant coated. Also have the intake port matched to the cylinder head. The dispersant coating cools the A/F charge down so much that frost formas at the base of the carbs on V8 engines...so you can see the cooling effect your intae can experience.

I would seriously consider an MSD ignition system....it does make a difference.

Then focus on getting an electric fuel pump/regulator along with an upgraded fuel line (to supply the extra fuel it needs to revv higher.

Get the SU's tuned in for the extra revving (tuning these is one of the most crucial tasks so go with an SU guru) and take that aircleaner housing and attach a good sized hose and extend it into the tunnel in the radiator support to suck cold air in.

Get some nice extractors and have them thermal barrier coated inside and out. The coating keeps the heat inside the header (Xtractor) and brings under bonnet temps down by at least 100 degrees F (it is a well known fact that for every 3 degrees dropped under the bonnet, the power to be gaine can be as much as 1 hp. IE:denser air charge

Call or email Schneidercams and ask them to fabricate a custom grind to suit your needs. keep in mind that streetable cam means the LSA stays above 112 degrees and the duration stays below 220, the lift on street friendly cams usually sits at or just below .500 inches anything over and you will need flycut pistons.

Loosing weight on the car can also gain power...an aluminum radiator will help mitigate the extra cooling requirement the car needs and shed some weight as would a space saver spare tire.

Fiberglass front fenders, hood, bumpers would also shed weight.

Now let's think about unsprung weight, an aluminum flywheel would allow the engine to spool up much quicker and makes for a VERY noticeable performance gain. SLotted or crossdrilled rotors also help get the car going faster, as would lighter wheels....ie:less rotational mass to get moving.

If you have cast rear drums for brakes, go aluminum or do a disc brake swap.

An electric cooling fan would also free up some ponies.

recurving the distributor is a good idea, Rebello racing herein California does this task for a reasonable amount of money.

Now that you have a good idea on how to make power, I would start thinking chassis work to put that hp or as you folks say KW's to the ground.

[Gav240z]

Well I think you've covered alot there Tiburon. I already have electronic ignition so that's not a worry. I have a set of Extractors that i was gonna get coated in HPC coatings.

I was also gonna do this to the intake manifold to keep underbonnet tempretures down.

I was definately gonna get the distributor recurved with the larger duration camshaft profile I would need it I believe.

I don't know how to convert compression ratio's from PSI across cylinders. So I have no idea what it's at for the moment.

At the moment a flywheel is out of the question as i'm running on a budget here.

I thank you for your input and all but for now I don't think it's possible to do all these wonderfull things. I was thinking since i'll have the E88 head off and swapping it onto my block since it's less tired i could do a few things to get that bit more out of it.

The electric fan is not of interest for me at the moment because the last Z I had the fan kept causing headaches so for now simplicity is bliss.

I have a set of Superlite rims which are pretty nice and lighter than the steel wheels.

The camshaft profile is already set and is pretty much on the street/track limit .

Anyway thanks again I will take all that into consideration and see what happens.

I saw a really nice set up for weber injection here...

But the price is a bit high and dunno what It would be here in AUS$ dollars.

http://www.racetep.com/ztripdcoe.html

[Ben]

http://www.injectionperfection.com.au/

[speedyblue]

Not interested in thermo fans?

Think about how much power it takes to spin the fan at 8000rpm (the front pulley is larger than the water pump one, hence gearing it up) There will be a few kilowatts there.

If quarter mile times are what you are after, the heavier flywheel will be what you are after. The extra mass rotating helps on gear change and take off, but if you are track racing, lighter is better.

Flat top pistons, like those in the P90 block give the 10:1 comp ratio, so yours may be less.

Remember, if you put a new head on with a half worn set of rings, the rings will wear out faster. but by the sounds of it, your rings are sealing fairly well.

[Gav240z]

I'm not interested in a Thermo fan only because of the headache the last one caused also I think to do it right I'd need a larger amp alternator as the 60-70 amps the Z puts out is not enough and ending up going through alternators every 3 months on my old Z.

I like the stock fan because it's simple and reliable.

I would have thought a lighter flywheel would be better for 1/4 mile times because it would help the car's acceleration. Obviously there's a give and take here.

Flat top pistons in the p90 block? i don't know of any P90 block i know of a P30 a n42 and F54. I have a n42 block here which is housing the E88 i want to swap onto the f54. The n42 has flat tops but it has tired rings also.

The original idea was to rebuilt the current E88 on the F54 and install a larger camshaft profile but it worked out cheaper to buy an entire engine with the block and put a good engine head on a good block.

Now however it's changed again I want even more power from it. However it still remains a budget and the original goal was to stop the valve stem seals blowing blue smoke .

Anyway my original goal was to built a fast z but no compromises, I wanted to keep the original SU's but webers do sound nice, have the stock fan, have a simple clean engine compartment and be able to work confidently on it myself. Also stay within budget but I'm starting to understand why so many go turbo, it may seem expensive but you get lots more bang for $$$.

Or I could use my P90 engine head in the garage which I was saving for a turbo project and build the same set up my mate has which I've seen how fast his car is on twin SU's only and go with something I know works. I just wanted to keep the P90 aside because here in AUS there scarce, but I guess it's not impossible to find another just don't wanna shave it and to get higher comp I'd probably need to.

[Tiburon]

Well, it sounds like you'll have to spend some money to get where you want to go....

YEs the 1/4 mile racing requires the stock flywheel, I like the lighter one because the spooling effect is instant.

I would seriously consider getting the best conditioned shortblock and getting the block rehoned and some total seal piston rings on some flat top pistons. Also go with clevite 77 bearings...have the crank and journal surfaces micropolished and oil feed holes chamfered.

if you're gonna spend some money, then it will best be spent building a stout bottom end.

then concentrate on getting the carbs tuned into the cam.

I would get the bottom half of the intake thermal barrier coated, and the top half heat dispersant coated. Have the interior ports of the intake bead blasted after portwork to better allow any heat to escape.

Have the exhaust portes polished to a mirror like shine.

Also look at your rear end gearing the more aggressive gears (numerically higher) will give you more bite....sacrificing your top end but kicking rear ends in the 1/4 mile.

I would also consider stiffening the suspension for better weight transfer during acceleration. (the less the car squats, the better)

time is wasted when the car takes the time to squat while transfering the power to the wheels. The stiffer the rear, the shorter the power transfer time, this means the wheel starts to turn sooner, making the car move sooner.

[Tiburon]

Gav just an afterthought,

If you used Painless wiring's electric fan wiring kit along with temp switches, you wouldn't have the problems you experienced...

The power freed up by intermittent use alone is worth the little trouble of wiring the fan up!!!

Oh..instant difference!!! mileage improves too!

Ever think of running an aluminum driveshaft? lighter rotating mass means quicker spools!!