New engine build

[JeremyH]

Seems like most of those guys prefer the vac pumps to the exhaust systems. I doubt I would have an issue running the exhaust setup with my exhaust and all that, but still.

That thread seems to indicate the vac pumps are slightly better performance wise. The other advantage is I could recycle the oil back into the system.

You got to be subjective, most guys that ran the exhaust evac said it worked great or gave tips to make it work. Just like breathers vs catch cans vs closed separator you will always have guys dead set on a certain way. I have learned when things are really expensive guys will always try to over justify their expense to guys that got the same result cheaper so take that with a grain of salt. Also a lot of those guys set on a vacuum pump are bigger displacement big block motors with more crankcase volume. Looks like most guys saw 4-10"with the header evac setup which most described as perfect and fixing their problem. No more oil seal leaks or blowing out gaskets etc. For an older big displacement na engine, by all means run a belt driven vac pump, they are proven to work as well. For modern lower displacement motors with tighter clearances and ring gaps you don't need a ton of vac all the time.

 

[one eyed willy]

I tired the exhaust evac before, didnt work well on my car. They say if you have mufflers it wont work so well. The check valve in mine actually went bad and because of the back pressure from the mufflers it was sending exhaust into the crank case. So keep that in mind, if that check valve fails and you have any sort of back pressure. I plumbed 2 of the check valves into my 3" downpipe just before the "y". After i installed it, it seemed to work, I could hold a piece of paper towel over the oil fill cap and it would have suction. wasn't too long after that i would test it and found the problem with the check valve and no more suction.

 

[Dubstep Shep]

I'll basically be running open headers with the R-spec, but at some point I'm gonna be pushing some stupid power. I still worry the vac won't be all that great at WOT at higher rpms

 

[Department Of Boost]

Seems like most of those guys prefer the vac pumps to the exhaust systems. I doubt I would have an issue running the exhaust setup with my exhaust and all that, but still.

That thread seems to indicate the vac pumps are slightly better performance wise. The other advantage is I could recycle the oil back into the system.

The header style vacuum setup is only good for about 3" of vacuum on a NA motor. Nowhere close to what you want to be running if there is an option of running a pump, which you can run at 15" no problem.

That said, 3" is better than 0".

 

[Dubstep Shep]

The header style vacuum setup is only good for about 3" of vacuum on a NA motor. Nowhere close to what you want to be running if there is an option of running a pump, which you can run at 15" no problem.

That said, 3" is better than 0".

That's what I thought. More is better in this case I imagine?

 

[Department Of Boost]

That's what I thought. More is better in this case I imagine?

To a point.

Read this:
http://www.dragstuff.com/techarticles/vacuum-pumps.html

 

[JeremyH]

I tired the exhaust evac before, didnt work well on my car. They say if you have mufflers it wont work so well. The check valve in mine actually went bad and because of the back pressure from the mufflers it was sending exhaust into the crank case. So keep that in mind, if that check valve fails and you have any sort of back pressure. I plumbed 2 of the check valves into my 3" downpipe just before the "y". After i installed it, it seemed to work, I could hold a piece of paper towel over the oil fill cap and it would have suction. wasn't too long after that i would test it and found the problem with the check valve and no more suction.

Yeah looks like those summit/jegs check valves don't seem to work so well, that link has some better replacement valves.

I like the idea of a hotside check valve right at the exhaust and then a "coldside" check valve by the valve cover.

That's what I thought. More is better in this case I imagine?

Most guys say over 10-12" is too much and can cause oiling problems. Seems most like a simple 4-5" vac. A modern boosted mod motor doesn't need a lot of vac anyway like the old motors.

 

[Department Of Boost]

Most guys say over 10-12" is too much and can cause oiling problems. Seems most like a simple 4-5" vac. A modern boosted mod motor doesn't need a lot of vac anyway like the old motors.

There seem to be a lot of opinions on this. The GZ Motorsports guy, who's living is vacuum pumps told me that 15" would be fine but if I wanted to be super safe run it at 10".

Like a lot of things there is probably a lot of "lore" when it comes to this. Kind of like the "water doesn't cool if you move it too fast" marlarky. Or "a -2deg pinion angle is always best, end of story". Another fine example of old school thinking.

I'm not saying I have an answer. I'm just real careful about who I get my info from and what their exact qualifications are. I have run into situations talking to "old school" guys who no doubt really know their stuff. But have some ideas stuck in their heads that have since been proven wrong.

 

[JeremyH]

True dat. Maybe look up what kind of vac a modern closed pcv setups pulls and try not to exceed that, be it a header evac kit, belt pump or electric pump.

 

[Dubstep Shep]

True dat. Maybe look up what kind of vac a modern closed pcv setups pulls and try not to exceed that, be it a header evac kit, belt pump or electric pump.

Seems like a good idea. OEM usually does pretty well with specs, it just sucks they have to meet emisions standards.

 

[JeremyH]

So, still researching, but looks like the modern oem closed pcv systems only draw 2-3" at idle and then another setup claimed 5-7", and then the pcv is closed at wot so no vacuum, but the other intake tube hose without the pcv valve creates a venturi effect as air passes through the intake tube to siphon out crankcase pressure. Much like the effect the exhaust evac setup creates, a low pressure educator to pull as the exhaust flows by.

I will stick to my breathers lol, or that magic contraption I posted seems legit lol

Yall have fun with your vac endeavors!

 

[BruceH]

I run a closed pcv and see over 20 in/hg or 10psi at idle. It reduces to nothing during wot.

I'm pro vacuum on the motor, lol.

 

[jodadejss06gt]

I'm about to be trying something different here soon; I just need my goodies to arrive!

 

[05Sleeper]

A friend of mine did a f150 coyote swap in his foxbody and to keep electric steering he used a pump from a Volvo. I forgot what model, I'll find the link. It was only like $110. Plugged right in with like 2 wires I believe.

 

[lito]

A friend of mine did a f150 coyote swap in his foxbody and to keep electric steering he used a pump from a Volvo. I forgot what model, I'll find the link. It was only like $110. Plugged right in with like 2 wires I believe.

That would have been probably to keep hydraulic steering, no pump needed for electric.

I run a closed pcv and see over 20 in/hg or 10psi at idle. It reduces to nothing during wot.

I'm pro vacuum on the motor, lol.

You are talking on manifold vacuum, I guess.

Update, took the car for a trip, engine behaved good and was heavily abused and still in one piece, long 120MPH cruises and a couple of 160 runs. But started having transmission issues, can't discard them not being related to the engine yet, will need to take trans out and see. That wont happen soon. Will report back.

 

[SStang]

Any updates?

Thanks.

 

[lito]

Small update, still having trans issues tested a couple of easy things without success before dropping the trans, will do soon, EPAS tested outside the car, it works so planning on getting needed parts for this.

 

[Department Of Boost]

Small update, still having trans issues tested a couple of easy things without success before doing the trans, will do soon, EPAS tested outside the car, it works so planning on getting needed parts for this.

I would be interested in the EPAS.

 

[lito]

I would be interested in the EPAS.

You already found the thread but for this thread completeness, here it is the link:

http://www.s197forum.com/forum/showthread.php?t=119778

 

[lito]

Update.

Think we solved the trans issues, trans is working correctly now. We made a huge screw up there. We installed the trans to the engine and dropped altogether into the car, we did not measure clutch stuff properly, we only checked slave range which looked good and went ahead with the install. I had a hunch that this trans may be different so I already had a shorter slave just in case, shame we did not measure stuff properly.

Now we had a Magnum XL at hand to compare and guess what, the Tremec aluminium bellhousing (Terminator unit) is way shorter than the SFI steel piece that comes with Magnum XL, about 12mm shorter. Slave range was good and actual clutch behavior was just perfect (using Exedy 07806) BUT slave shaft rubbed badly with the clutch discs as it was about 10mm too long.

When we started the car, we had a whistle that went away quite quick, that was the cause, the disk hub grinding the slave shaft away.

Now, a few days after startup, at high speed pulls the whole thing started to vibrate, we think that the pressed discs and ground rubbing slave shaft forced the disc out of centering, making the input shaft run all over the place and it destroyed the pilot bearing.

So we were left with a broken slave, destroyed pilot bearing and damaged input shaft. Clutch looked brand new except some marks on the disc's splined hub but nothing that would affect its function.

The input shaft damaged splines are out of the area where the disc hub slides so we just cleaned so it would slide back just in case, I had a shorter slave already so we did all the measures as we needed a spacer to make it closer for it to work, checking the two transmissions, three sets of clutch/flywheels we decided for an 8mm spacer.

Got it done, installed same clutch, new pilot bearing, spacer and shorter 10+ slave and car is running great again.