3.4c mods?? Want lots of N/A power

[d.o.h.c]

God son, my finger are gonna have arthritis.

[d.o.h.c]

#3. Yes that is what I used on my heads and cam carriers, becasue they are aluminum, its a little easier on the dremel. Just make sure you dont hit the head surface, or your head will be prone to leaking and then you have a gasket leak short after that, unless you have the heads milled, which raises the compression.
#4. Good idea, I have a 60degreev6 book with a write up, I can make a list for you if you want
#5. Blue printing is making sure that all of the compnets in that certain area are perfect. So my oil pump I took it apart, and made sure that all the gears had no sharp edges on them, they rolled smooth and everything was tight. I also took my dremel to this and took the flashing out.

[pwmin]

1. Anyway, I'll go with the 96 heads since they have better flow and compression. If I find a 97 engine in the junk yard, would the 97 cam carriers and lifters work with my 96 heads and 94 valve springs?

2. And if the 95 cams work with the 97 carriers and lifters, would it be worth using them instead of the 97 cams?

1. yes, and that would be a better choice since they have smaller and lighter lifters. i would get lightweight lifters, too (if they make any).

2. they will work. if you have it all apart and don't pay much for them, it's worth it, IMO.

[SappySE107]

Running too much oil pressure will hurt your bearings and promote leaks. Its a waste of hp as well. Rule of thumb, 10 pounds per 1000 RPM. Stock pump is on the high side so stick with it. Focus on oil drainback and windage. A crank scraper would do the DOHC some good and a better oil pan if you autocross or race the car.

[d.o.h.c]

I dont want to argue, but more oil pressure is much better than low oil pressure, even more so if he plans to add a turbo later on. As far as oil pressure eating HP, like I said before, I wsould rather sacrafice a couple HP for more oil PSI. The oil pump on the DOHC is good, just needs to be modify a little. As far as a crank scraper,I asked my father about this when we were building my motor, he did not like the idea of a piece of sheet metal being so close to the crank shaft. Now he is old school, so maybe he is wrong about them, but I did not use them. He has been building motor for 35 years. Thats my 2 cents

[SappySE107]

I agree, high is better than low. High is worse than correct. That is my point. If you can modify the stocker (better tolerances) then go for it. I assume a turbo would want more volume from the pump, not necessarily more pressure.

Sheet metal? I dunno what they used 35 years ago but even the pics I have seen from the 70s weren't sheet metal. If you don't clearance it properly, it will fail. If you do it proper, then there are worse issues with your bottom end than the scraper if it fails. For what it would do on the 3.4 DOHC, and what you have done, it makes no sense to me not to use one. Especially for your application. My 2 cents.

[OldSkoolGP]

This post has been going on this long and I haven't put my .02 in? I must be slipping in my old age!

OK, first off, I agree with almost everything that has been said, except one or two things. And I'll tell you up front, everything you are planning on doing with your car, I have and am doing right now. I do high speed autocross (one lap of a road course against the clock) and drag racing with mine (PB 14.32). I've been doing this for 4 years now and I've had my engine apart enough to know what I'm talking about.

1) Yes, you can have too much oil pressure. You never want more than 75 lbs. of oil pressure in this motor or you can blow seals and gaskets. I know this because my first year drag racing I went for fourth and got 2nd. 9000 RPM for a split second was enough to blow the gasket on the oil galley cover. Going with Ben's formula of 1000RPM = 10psi that was about 90 psi. Another reason you don't want too much pressure is because pressure creates heat, and you can foam the oil at high revs causing lifter tick which decreases valve lift thereby reducing power. Keep it simple, find a synthetic oil you like and change it every 2000-2500 if you're going to primarily race. If you go with the 60V6 lightweight lifters and you get lifter tick, switch from 5W-30 to 10W-40.

2. '97 heads flow better? Not sure if anyone ever confirmed that. They are higher compression, and if you use them one guy does make headers for them. We are currently working on getting headers made for the 91-95 heads. If you're going to go that route, you should just get a complete '97 engine, then you'll get the good intake and all the top end parts you want. My setup is slightly different. I'm using the 91-95 heads, but I have the '97 intake and '96 cams so I can run OBD-II. I like the 91-95 heads because the exhaust ports I think have a better shape and they have a hemispherical combustion chamber. Not sure is the 97 heads do, never looked into it, but I don't like their exhaust ports. And unless you're doing headers, you have to use stock manifolds that have those damned A.I.R pipes on them for emissions so you have to block those holes off. 91-93 automatic manifold do not have these A.I.R holes.

It will be an interesting setup. I don't think anyone has done P&P '97 heads on a DOHC, so it will be a good comparison. Are you planning on running OBD-II or some kind of aftermarket computer?

[z34phoenix]

FYI the 97 exhaust manifolds dont have the AIR ports in them.

i never heard of the 97 being higher compression via the heads... i always thought the diff on the compression from 96 to the earlyer was the pistons....

i have plans to do ported heads... but not sure on time frame of when it will happen.

[SappySE107]

96-97 heads have a smaller combustion chamber.

[series8217]

1) Yes, you can have too much oil pressure. You never want more than 75 lbs. of oil pressure in this motor or you can blow seals and gaskets. I know this because my first year drag racing I went for fourth and got 2nd. 9000 RPM for a split second was enough to blow the gasket on the oil galley cover. Going with Ben's formula of 1000RPM = 10psi that was about 90 psi.

The oil pump has a pressure bypass valve that redirects oil out of the pump after ~75psi or so. It is unlikely that you reached 90psi as this would require a large volume beyond the maximum flow of that bypass outlet.It's more likely that 9000 RPM did something scary like flexing the block.
If you look at that gasket there isn't really any way you could blow out the parts that carry pressurized oil. They're o-ringed and have a huge amount of material between the o-ring and the outside.. I'll bet the block flexed or it was just coincidental.


Anyway, if I recall correctly the stock pump doesnt really get to 75 psi even at redline once your oil is warmed up (unless your oil is pretty thick; but then you're just restricting flow). So even if you upped the spring rate on the pressure bypass, you'd really only increase your flow at moderate and high rpms when the oil is cold where its getting up to the pressure bypass level at reasonable RPM.. but you shouldn't be revving the motor that fast anyway when its cold as you dont have enough oil flow to adequate protect your bearings and cam surfaces. I wouldn't increase the oil pressure.

[OldSkoolGP]

The oil pump has a pressure bypass valve that redirects oil out of the pump after ~75psi or so. It is unlikely that you reached 90psi as this would require a large volume beyond the maximum flow of that bypass outlet.It's more likely that 9000 RPM did something scary like flexing the block.
If you look at that gasket there isn't really any way you could blow out the parts that carry pressurized oil. They're o-ringed and have a huge amount of material between the o-ring and the outside.. I'll bet the block flexed or it was just coincidental.

You're right about the bypass valve. However, if you blocked it off like I did so you force the oil to always go through the filter, you can reach 90 psi. It also sounds like you're thinking of the O-ring for the pupm drive gear when I'm talking about the paper gasket for the oil distribution cover which did blow from excessive crankcase pressurel.

[series8217]

You're right about the bypass valve. However, if you blocked it off like I did so you force the oil to always go through the filter, you can reach 90 psi.

No, you don't understand.. The bypass valve you blocked is the oil filter bypass valve. All that does is bypass the filter if the pressure differential accross the filter is greater than something like 10 or 15 psi (I don't know the exact mount). It doesnt even operate the same way as the oil pump bypass valve / pressure regulator:
The oil pump itself has a spring in it that holds a valve closed until the pressure at the pump reaches a certain absolute value (around 75psi), then it starts to open, bypassing oil out of the pump back into the pan (or in the case of the 3.4 DOHC, to the distributor plug gear area first, from which it flows back into the pan).
If you block the oil pump bypass gear you could easily blow out gaskets or destroy your oil pump drive gear if you tried to run the pump at high rpm while the oil is thick and cold.

It also sounds like you're thinking of the O-ring for the pupm drive gear when I'm talking about the paper gasket for the oil distribution cover which did blow from excessive crankcase pressurel.

What? You said the oil pressure was enough to blow the cover. Now you say it blew from excessive crankcase pressure. What you're saying now is likely correct. It certainly didn't blow from oil pressure like you said before. The oil passage going through that cover is too small and too well-sealed to be popped from oil pressure, even if you had over 100 psi. Keep in mind the pressure here is also MUCH lower than at the oil pressure gauge, since the oil pressure gauge is pre-filter and there is a pressure drop across the filter.. additionally there is pressure lost after the first oil galley since some of the oil is coming out of intermediate shaft bearing clearances, main bearing clearances, and rod bearing clearances. Also, you would blow out your oil filter o-ring far before you blew out a large gasket like the one on the oil distribution cover; especially since your filter bypass is blocked off.


Also, a note for anyone thinking about blocking off your filter bypass.. Do some research on filter flow; you will see that you're starving your motor for oil at high RPM by having the filter bypass blocked off, unless you're using a dual or triple filter system to reduce restriction to flow. You want your engine to have full oil flow at any RPM regardless of whether or not the filter is blocked or can flow enough! It's much better to have a few particles in your oil at 7000 RPM than to be starving your bearings! The tri-layer bearing material is designed to embed particles in the soft first layer to prevent them from dragging on the crankshaft. This layer is NOT designed to keep the bearing free under oil starvation conditions. There ARE bearings now which can do so; they are coated with a layer of teflon and some other polymers to provide an incredibly strong and slick surface to protect the bearings from spinning if there is temporary oil starvation. These are not yet available for the 60* V6 and are not a fix for poor oiling.

[OldSkoolGP]

Also, a note for anyone thinking about blocking off your filter bypass.. Do some research on filter flow; you will see that you're starving your motor for oil at high RPM by having the filter bypass blocked off, unless you're using a dual or triple filter system to reduce restriction to flow. You want your engine to have full oil flow at any RPM regardless of whether or not the filter is blocked or can flow enough! It's much better to have a few particles in your oil at 7000 RPM than to be starving your bearings! The tri-layer bearing material is designed to embed particles in the soft first layer to prevent them from dragging on the crankshaft. This layer is NOT designed to keep the bearing free under oil starvation conditions. There ARE bearings now which can do so; they are coated with a layer of teflon and some other polymers to provide an incredibly strong and slick surface to protect the bearings from spinning if there is temporary oil starvation. These are not yet available for the 60* V6 and are not a fix for poor oiling.

This is simply not true. The filter bypass is there to prevent excessive oil pressure from damaging the filter, especially when the engine is cold. The last time I checked, an oil filter is not a massive restriction to flow. And if you're using good filters, you don't have to worry about a pressure difference across the filter element. Oil filters are a lot better today than they used to be and they can handle the higher pressures. If blocking the bypass is as detrimental as you say it is, I think I would have noticed something by now. Yes, Tri-metal bearings can operate fine with slightly dirty oil, but it's certainly not a good idea. And the only time the bypass would even be working is with cold oil. Blocking it does not starve the engine of oil, period.

[series8217]

This is simply not true. The filter bypass is there to prevent excessive oil pressure from damaging the filter, especially when the engine is cold. The last time I checked, an oil filter is not a massive restriction to flow. And if you're using good filters, you don't have to worry about a pressure difference across the filter element. Oil filters are a lot better today than they used to be and they can handle the higher pressures. If blocking the bypass is as detrimental as you say it is, I think I would have noticed something by now. Yes, Tri-metal bearings can operate fine with slightly dirty oil, but it's certainly not a good idea. And the only time the bypass would even be working is with cold oil. Blocking it does not starve the engine of oil, period.

You're contradicting yourself. If the oil filter isn't a massive restriction to flow then why would you need to block off the bypass valve? If the bypass valve is opening its because there is a 15 psi pressure differential across the filter. If you have to block it off to keep the filter from being bypassed, which you claim to have done, then you are now dealing with a restriction that creates an additional 15 psi of pressure pre-filter. Otherwise there was no point in doing it.
Another thing to think about.. if you have an extra 15 psi due to restriction at the filter, this is between the oil pump and the filter and the oil pump bypass valve will see this pressure. It will divert oil flow back to the pan to regulate its pressure if the pressure gets beyond the 75 psi set point (which now indicates an actual post-filter pressure of 60 psi; and reduced flow!).

[OldSkoolGP]

You're contradicting yourself. If the oil filter isn't a massive restriction to flow then why would you need to block off the bypass valve?

Blocking the bypass forces all the oil through the filter. And I'm not contradicting myself. You're trying to make it sound like I am, though. Look at what I typed more carefully. I'm not saying the filter is a restriction. It will flow as much oil as the system can shove through it. It will handle, 70, 80, 90psi just fine, but the bypass will open long before that. Think about when this engine was made. Do you really think the oil filters made in 1990 are the same quality as the ones today? Filters today can handle higher pressures. The bypass was put there to protect the filter. If your filter doesn't need protection, you don't need the bypass.

And consider this. The oil pressure sensor on the oil cooler comes AFTER the filter, not before. If blocking the bypass restricts oil flow, like you claim, why do I have much better pressure than I did before I blocked it? My idle oil pressure has gone from 18psi to 33psi. If you think I'm crazy, fine. But how do you explain the results?