Expectation From New Engine Build?

[heyitsrama]

Check out this book it has some interesting insights. 
 

https://www.ebay.com/itm/275245952328?epid=102900406&hash=item4015efed48:g:EKkAAOSwxidiRwqX

[Diseazd]

8 hours ago, Ownallday said:

 

One last question, would it be wise to get the engine balanced too? I wouldn't mind being able to rev the engine beyond 6k (which is the most my motor currently goes). But I heard it's not necessary to for these engines. Some feedback on that would be great!

No need to balance an engine for 7000 rpm. One more thing. If you install a Stage III cam, you’ll need to geometry the cam with .160 to .180 lash pads (center the wipe pattern on the rockers) but in the E88 head, you’ll also need the shorter valve seals to prevent the valve retainers from contacting the seals with the higher lift. If you guys are doing this build, you’ll need to seek advice as you progress from those on this site that have done this before.

[siteunseen]

I've gotten lazy over the years after building my 2.4. I did balance the rods and piston cups out of boredom, they were very close from the factory but older 240 aren't as close as the 280s from all I've read. Anyhow the darn thing runs so good and fun to drive-iness I attribute to the 10Lb aluminum flywheel I put in. It's fast enough for my weekend drives around here. One day I'll put the e-31 and cam kit together but no rush. Anyway...

Diseazd is talking about this I believe. He gets his from Eiji at Datsun Spirit I think but I bought felpros for a Ford after reading a whole helluva a lot about all this.

https://forums.hybridz.org/topic/25807-improved-l6-valve-stem-seals/

My still in the bag, on the shelf with the rest of the goodies waiting for life to get back to boring.

Edited May 4, 2022 by siteunseen

[Ownallday]

14 hours ago, Diseazd said:

No need to balance an engine for 7000 rpm. One more thing. If you install a Stage III cam, you’ll need to geometry the cam with .160 to .180 lash pads (center the wipe pattern on the rockers) but in the E88 head, you’ll also need the shorter valve seals to prevent the valve retainers from contacting the seals with the higher lift. If you guys are doing this build, you’ll need to seek advice as you progress from those on this site that have done this before.

Sweet, 7k is what I wanted to shoot for! Having the car die off before even hitting redline is dissatisfying. And sounds good. I have a set saved already. What valve seals do you recommend, is it the Fel-Pro #SS72686 or something else? And 100%. I will have to revive this forum and make a new one once the progress starts. Any other things that I should have done to the block that have not already been mentioned? Thanks for the info again!

 

15 hours ago, siteunseen said:

I've gotten lazy over the years after building my 2.4. I did balance the rods and piston cups out of boredom, they were very close from the factory but older 240 aren't as close as the 280s from all I've read. Anyhow the darn thing runs so good and fun to drive-iness I attribute to the 10Lb aluminum flywheel I put in. It's fast enough for my weekend drives around here. One day I'll put the e-31 and cam kit together but no rush. Anyway...

Diseazd is talking about this I believe. He gets his from Eiji at Datsun Spirit I think but I bought felpros for a Ford after reading a whole helluva a lot about all this.

https://forums.hybridz.org/topic/25807-improved-l6-valve-stem-seals/

My still in the bag, on the shelf with the rest of the goodies waiting for life to get back to boring.

Okay so no balance necessary. Thats what my goal is to have a fun car that can be daily driven if needed but not get beaten by everything on the road haha. I do already have a 10lb flywheel also. The car revs nicely as is. Is it the same felpros mentioned in the forum or will anything else work nicely? I believe I saw Fel-Pro #SS72686 for the part number. Thanks for the info!

[siteunseen]

Mine are fel pros I'm 99.9% sure. They were easily available at the time from local chain auto parts store. 

I have some more info from my build thread I can post too, also on my laptop unfortunately. I can get that for you this weekend when I'm off work. Hopefully you're in the planning stage and not in a hurry...

[Ownallday]

19 hours ago, siteunseen said:

Mine are fel pros I'm 99.9% sure. They were easily available at the time from local chain auto parts store. 

I have some more info from my build thread I can post too, also on my laptop unfortunately. I can get that for you this weekend when I'm off work. Hopefully you're in the planning stage and not in a hurry...

I just saw on the forum I actually have the right part. Thank you. They are indeed felpros for a ford. I am far from doing the build, right now I am just gathering the parts needed for the build. Don't plan on pulling the motor till July when my friends schedule frees up so no rush.

[siteunseen]

On 5/4/2022 at 1:57 PM, siteunseen said:

Mine are fel pros I'm 99.9% sure. They were easily available at the time from local chain auto parts store. 

I have some more info from my build thread I can post too, also on my laptop unfortunately. I can get that for you this weekend when I'm off work. Hopefully you're in the planning stage and not in a hurry...

I found this after a quick look a my thread. Me and @madkaw had figured out a repeatable depth procedure as they will bulge if yo put them on too far/deep. Hope it helps. Ask again and I'll try harder but I remember using feeler gauges stacked together to get the same depth/height, whichever way you're looking at it. I used the distance from the head up to the bottom of the seal's bottom side of the metal band. 

https://www.classiczcars.com/forums/topic/50909-72-240z-rebuild/?do=findComment&comment=475701&_rid=23570

 

[Zed Head]

On 4/27/2022 at 7:25 AM, Ownallday said:

compression measured ~100-120psi in the cylinders

 

On 4/27/2022 at 7:25 AM, Ownallday said:

According to OZDAT my static compression is 8.280

 

On 4/27/2022 at 7:25 AM, Ownallday said:

E88 head was rebuilt (Not sure where or what they did exactly)

 

On 4/28/2022 at 6:23 AM, Ownallday said:

E88 I have is already rebuilt, ported, polished etc

 

On 5/4/2022 at 9:30 AM, Ownallday said:

7k is what I wanted to shoot for!

I haven't built any engines but a few things popped out at me when I read through the thread.  Did you use an adapter when you measured cylinder pressure, and did you open the throttle bores and get a good cranking speed?  Your pressure numbers are way low, they look like adapter numbers.  The adapter makes the combustion chamber seem bigger.  With 8.3 CR you should have higher pressures.  Like 150 - 185. I got 185's on a stock 1978 L28.  No adapter, small gauge volume.

What, exactly, is in the head will be important.  The main advantage of the other heads is the bigger valves and ports.  You need that if you want to hit 7000 RPM.  The E88's have a smaller intake valve, I think, than the L28 engines.  I have read about two forms of E88 head also.  I think the difference is in the size of the combustion chamber.

You probably won't be able to make a good decision until you get the head off and see what's in it and has been done to it.  The people that do engines say the power is in the head.  Or, conversely, the head is what's holding the engine back.  The heads just don't flow well in stock form.

Just regurgitating...

p.s. you can look up some of jmortensen's old posts and he says that all of the "Stage" cams are pretty low on the "radical" scale.  He tried all of them I think and didn't really have any problems.  He always recommends going bigger, the 1 and the 2 are barely changed from stock.  He was unimpressed with them. 

 

 

Edited May 7, 2022 by Zed Head

[Ownallday]

On 5/7/2022 at 4:21 PM, Zed Head said:

 

 

 

 

I haven't built any engines but a few things popped out at me when I read through the thread.  Did you use an adapter when you measured cylinder pressure, and did you open the throttle bores and get a good cranking speed?  Your pressure numbers are way low, they look like adapter numbers.  The adapter makes the combustion chamber seem bigger.  With 8.3 CR you should have higher pressures.  Like 150 - 185. I got 185's on a stock 1978 L28.  No adapter, small gauge volume.

What, exactly, is in the head will be important.  The main advantage of the other heads is the bigger valves and ports.  You need that if you want to hit 7000 RPM.  The E88's have a smaller intake valve, I think, than the L28 engines.  I have read about two forms of E88 head also.  I think the difference is in the size of the combustion chamber.

You probably won't be able to make a good decision until you get the head off and see what's in it and has been done to it.  The people that do engines say the power is in the head.  Or, conversely, the head is what's holding the engine back.  The heads just don't flow well in stock form.

Just regurgitating...

p.s. you can look up some of jmortensen's old posts and he says that all of the "Stage" cams are pretty low on the "radical" scale.  He tried all of them I think and didn't really have any problems.  He always recommends going bigger, the 1 and the 2 are barely changed from stock.  He was unimpressed with them. 

 

 

No additional adapter was used, And I used my friends Snapon Gauge so it's not some cheapo one. I had the engine at operating temp, throttles open when cranking, and battery was on a tender while testing too. Not sure if I mentioned this but I am losing about a QT of oil every 1k miles. Exactly what I thought as I saw most people are getting in the 200s with a good motor.

So I can confirm the head was port and polished as when I got the head that was the only thing the guy told me he knew was done to it and it was obvious as you can see the ports were nice and polished. I thought the 260z E88 had bigger valves but just had worse flow compared to say the N42? I also think the guy had the current cam just cleaned up and new valve seals.

I have been told this too. The main reason I want to stick to the E88 is because it's what I have already and works as I don't want to spend so much money buying another head and having to get a machine shop to work on it.

Interesting, I will keep that in mind but most likely will end up going with Stage 3 since that what was recommended and even my friend helping me build the engine said Stage 3.

[Zed Head]

I wonder if there was some combustion chamber valve unshrouding done.  Those pressures just seem really low like the combustion chamber is enlarged.  You could use one of those calculators, like OZDat, and back track to combustion chamber volume.  Then recalculate to what CR would be with flat-tops.  You might find that you'll still have low CR.

Or maybe you just have really bad rings.  Seems like if you had bad rings you'd have some variation across the six.  One or two cylinders much worse than others.  Good luck.