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Zaloryan
04-23-2009, 03:36 AM
From what I understand, a 3300 V6 is a de-stroked version of the 3800, which are both Buick motors. I've been poking around and researching some performance ideas, and I'd really like to tap into the performance potential of the 3300 and walk out on some unexplored ground for us 3300 owners. That being said, here are my questions:

A) I've read about a 3 angle valve job being done to the cylinder heads. Is the investment worth the benefit?

B) Rocker Arms. The 3300 is a roller motor, but sports solid rockers. I know the aluminum rockers cannot take the low RPM punishment of a daily commute, so how about some steel roller rocker arms? Perhaps the threads could be retapped & I could install some Chevrolet steel rockers? COMP Cams makes some Magnum rockers. If this were done, would I have to get some different pushrods to be capable of oiling the rockers? I know the Lunati sells a pushrod checker...

C) If I change the rockers, will I have to swap out the valve covers for clearance purposes? I am aiming to stick with the stock ratio: 1.6:1. Will some metal valve covers from a 3800 fit and what series was equipped with metal valve covers?

D) A custom grind camshaft is definitely in the works here. I know for a fact that stiffer springs will be in order. Any recommendations?

E) Compression Ratio: I don't know the stock compression ratio, but I will rebuild the motor with some cast hypereutectic pistons from Sealed Power. What would be a good ratio to go for so I can stay on 87 or 89 octane?

Thanks to any knowledgeable comments & suggestions!

-Mitch

Zaloryan
04-25-2009, 04:21 AM
Anyone have any ideas?

Jr's3800
04-29-2009, 12:33 AM
If you have a 93 3300 you should have the newer style heads...

Also you have a 9.0 to 1 compression ratio bone stock..


I recently took the 3800 out of my van... So here is a better pic of the Roller rockers.. This engine also had 1.6 rockers stock but use the roller pivot... The rockers in the Pic are 1.8's... Good for roughly .460 total valve lift on stock springs
http://img.photobucket.com/albums/v294/Jr3800/1995%20Pontiac%20Transport/Vanengineswap028.jpg

Zaloryan
05-01-2009, 05:55 PM
Okay, let's say I wanted to use the roller rockers that were equipped on your 3800. What series is the 3.8 and what could I find it in? Is this motor specific to U-Bodies or A-Bodies? From what I know, the stock ratio on my 3300 is 1.6. What should I do to convert to the 1.8 ratio provided with the roller rockers?

Jr's3800
05-01-2009, 09:53 PM
The rockers you see in the pic are Yella Terra 1.8 Roller rockers..

There is a rocker for a 3800 with the larger pedestal bolts that your 90 3300 should have( should be the same as a 3800 ).. Intense-Racing or ZZ Performance should be able to get the proper Yella Terra roller rockers for you..

A 3 angle vale job will be ok... 5 angle would be better... Not sure in your case how much you could gain from this tho..

The roller pivot is not really worth adapting them to your engine.. They will still be 1.6 as well..

If you swap out to the yella terra rockers you'll have no issues with the valve covers.. And IIRC the 88-89 3800 valve covers are aluminum and will be exactly what you need.. The Aluminum 3800 covers from the Firebirds and camaros will be missing the PCV port on the front cover..

For your compression... I'd just about stick with stock...9.0 : 1 ... Possibly up to 9.4 or 9.5 : 1.... Even shaving the heads a bit will add compression..

cutlassburnin
05-02-2009, 08:20 PM
Did you feel any real improvement after you installed the rockers jr.?

Jr's3800
05-02-2009, 09:16 PM
Yes the Mid range to red line was stronger.. You are simply pushing the valve open further... an example would be say stock intake is .400 or .405 you be near .460 with the rockers..

turbokinetic
05-05-2009, 03:33 AM
Don't forget to port the heads while you have it apart. This will make a very noticable improvement in the engine's midrange to high RPM power. You don't have to do anything crazy. Simply bowl-blending the ports and gasket-matching the runners between the heads and manifolds gives a very good HP return on the time invested.

When the valves are ground, they can "back cut" the valve faces. This is a procedure done on the valve grinder to remove any remaining "ridge" between the face sealing area and the head fillet. It will improve flow right as the valve opens and just before it closes.

I've been running 9.5 CR on my mom's 3800 for a while now, and it works great. The timing was conservative enough in the factory calibration that it hardly ever shows any knock-retard.

On my iron-head 305 V8, it has 10:1 and requires premium gas. With cheap gas it has about 8 to 10° of knock retard. This engine gets 26 MPG.

I would recommend 9.5 for a non-boosted engine.

Go with forged pistons, instead of hypereutectic. They are not that much more expensive and they are very much more durable, especially if the engine does any detonating from the higher compression. They are also less likely to seize during initial start-up because they start loose and expand to match the bore size as the engine warms. The hypers start tight and stay tight. Also - with all the breathability you will have the engine will want to revv alot higher and the forged pistons will withstand high RPM use more safely.

My machinist talked me into them for the 3.8 Turbo. I was concerned that about the knocking and other problems when cold. I've driven the car for 6000 miles now. There is no noticable side effects when cold. The engine sounds about like any other 3.8. The only "different" sound is the valvetrain clicking from the .498 lift roller cam!

I don't have any experience with the roller rockers, but they look like a great idea! I ran out of time when I put my engine together. Next time I have to go into it, that is a definate option. I will have to stay with stock ratio rockers with the high-lift cam in my engine.

Will be interested to hear how your project turns out!

Zaloryan
05-05-2009, 03:53 AM
This is great information, thanks everyone!

I have been asking around on these possible improvements, and a former machinist told me that the 5 angle valve job is for extremely high RPM operation, and would not hold up to the abuse of being driven daily. What's everyone's opinion regarding that?

turbokinetic
05-05-2009, 03:56 AM
Forgot about the cam and valvesprings!

When I ordered my cam from Competition Cams, they had a recommended spring and rocker ratio for this cam lobe profile.

Even if your cam has to be custom-made, the shape of the lobes and the lift of the lobes will be a standardized profile that the cam manufacturer uses for different engines. They will probably give you a part number of spring that is required for that particular cam.

The newer springs have a "beehive" shape, where the top of the spring (near the rocker) is smaller than the bottom. This lets the spring cap be smaller indiameter; therefore lighter, reducing reciprocating valvetrain mass. They look strange at first, but they take alot of stress off the cam and rockers at high RPM.

Whatever you do - follow the cam makers recommendations on the spring. Things can get very expensive in a hurry if you break a spring and drop a valve.

Remember with the cam specs - place the powerband in the area where the engine runs during acelleration. As you shift out, notice the RPM range the engine goes thgough as the transmission shifts out. You want the engine to have the greatest torque throughout this RPM band. This means FAR MORE than the engine's peak HP.

This is the cam in my engine, the info provided for yours will be similar. (the types of info not necessarily the numbers themselves. They will give a RPM range, and part numbers of the springs for the cam in other words)
http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=46&sb=2

turbokinetic
05-05-2009, 04:04 AM
No idea on the 5 angle valve job. Maybe it gives extra perfomrance, but at the expense of a very high rate of wear, so that it will wear out prematurely.

Normally a "valve job" is 3 cuts on the valve head, and the seat is cut one or more times. I will ask a friend about that.

Thanks,
David

turbokinetic
05-06-2009, 02:02 PM
My original question to Mike, my professional and knowlegable machinist:



I had someone ask this on a forum. Have you ever heard of a 5 angle valve job? ... Does it really cause the valves to "wear out" sooner
than a "normal" valve job?

Here is his quote from the forum, what can you tell me about this? Thanks!
David

"I have been asking around on these possible improvements, and a former
machinist told me that the 5 angle valve job is for extremely high RPM
operation, and would not hold up to the abuse of being driven daily. What's
everyone's opinion regarding that? "


Here is his reply, which was in 2 parts:




David,

Yup, it's 2 angles on the valve, a 45* ans a small 30* back cutt, and a 3
angle onthe seat, 30*, 45* and 60*, Some heads, most heads benifit from the back cutt on the valve, it improves flow.
Mike

-------

I suppose under the right circumstances a narrow "race style" seat could get beat in, or burned easier than a wide ol' single angle seat. The fact is if something is wrong, it's gonna die!

When i do the 5 angle treatment, the back cutt on the valve is superficial on the surface, just .015 to .025 @ a 30* angle (This varies). The back cutt helps direct airflow as the valve opens. It helps very little at anything past
100 thousandths (0.100") open. Some like to take the back cutt all the way to where the valve seats, but time and time again it's shown to slow down flow.



Hope this clarifies things!
David

cutlassburnin
05-06-2009, 03:42 PM
Ive been thinking of doing my "stealth" intake manifold with a bit of polishing, just dont know if all the works worth the 5-6 hp gain.

Zaloryan
05-08-2009, 04:49 AM
Mmm, very interesting! Thanks David. A 3 angle valve job it is.

On a side note, I have a transmission swap question. Bessie is of the year of 1990 and has a cable controlled three-speed automatic. If I swap out for a four speed overdrive, does it have to be from a 1990 A-Body, or is that irrelevant as long as I use the PROM from the donor car?

turbokinetic
05-08-2009, 01:03 PM
Mmm, very interesting! Thanks David. A 3 angle valve job it is.

On a side note, I have a transmission swap question. Bessie is of the year of 1990 and has a cable controlled three-speed automatic. If I swap out for a four speed overdrive, does it have to be from a 1990 A-Body, or is that irrelevant as long as I use the PROM from the donor car?

AFAIK the 3-speed cars ECM's did not monitor the transmission in any way, so the ECM would not care if it had a 3 or a 4 speed. It should work no problems. Just re-pin the connector so the lockup converter would work.

Depending on the year of the transmission, I have most of the factory 125C and 440T4 diagrams and can give you a diagram of what is needed to make the lockup work.

You'll need the CV shafts, mount brackets, shifter cable (unless you mod the original one) transmission-end of the cooler lines, and the correct governor (speedometer cable or magnetic speed sensor). That's about it.

David