LarryD

I have read the articles on making the swap and everything looks pretty straight forward but I do have a couple of questions on buying new components and looking for recommendations.

This is a 92 Camaro that is my daily driver with a T5 and non-posi 10 bolt. That said, the original factory engine that blew at 135,000 miles got 36mpg on the highway and 28mpg city. Sure miss that as the replacement 3.1L crate motor only got 28mpg highway and 22mpg city. I am looking for a 3.4L block now to make the swap and will do a full rebuild on it first. Now to the questions.

My current 3.1L oil pump is pretty whimpy. Looking for a recommendation for a replacement oil pump and should it be one for the 3.4L or one for the 3.1L block? The article on the swap appears to say bring over the 3.1L oil pump so since the pan has to come over I assume the 3.4L pump will not fit.

Now to the cam shaft. I would like it to be fuel efficient and high mileage but not over sacrifice power. The original engine had very good power with very good mileage but don't know what that cam was. Looking for a recommendation on what cam to buy and again, would this be a cam for the 3.4L or a cam for the 3.1L?

I haven't gotten the 3.4L block yet so don't know the condition. If I need to have it bored, what is a good recommendation for replacement pistons given my note above about daily driver, fuel efficient, and reasonable power?

And lastly, the article says to bring over the 3.4L fuel injectors. Is the recommendation to stay with the same fuel pressure regulator for the 3.1L?

Thanks....

Six_Shooter

iTrader: (2)

AFAIK, the 3.4 and 3.1 oil pumps are the same, the only possible difference could be the pick up tube size, but I think this was a year change not a displacement change.

Camshaft has a lot of variables. A popular choice is the Crane 260-2 (or whatever the new model number is) and similar camshafts from other manufacturers. It has a decent power increase without sacrificing too much in economy. The camshaft from a 2.8, 3.1 and 3.4 will fit the 3.4 block. The only reason to use a 3.4 cam is is the SFI system is being retained, which is not common practice in a 3rd gen. The SFI system requires a cam sensor input, and the 3.4 cam has a specific trigger for this sensor.

If the block needs to be bored, it is recommended to only go large enough to clean uo the bores. A stock replacement piston of the correct bore new size will serve your purposes.

Retaining the 3.1 intake and injection system retains the same regulator. I'm 99% sure that the fuel pressure is the same between the 3.1 and 3.4.

LarryD

I have the 3.4L engine now and pulled it apart today.. Cylinders look good.. So, what cam did the stock 92 3.1L use versus the 95 3.4L? I see recommendations for either a 262 or 252 cam but how do those relate to the original cams?

Thanks...

Maverick H1L

iTrader: (8)

Um, the factory cams are the same between the engines except that the 3.4 has the trigger for the CMP... Don't bother swapping unless you want a power boost (and then you may need to tune the ECM).

Everything above the heads stays the same (in other words, use the 3.1 parts above the heads). Except the fuel injectors, which are, on average, 3-4# bigger than factory 3.1 injectors.

LarryD

So, the 95 engine 3.4L is disassembled for rebuild to go into the 92. The plan is to take the block with crank and camshaft in place and the heads with valves in place to a machine shop for work. They will hot tank it all, check for cracks, replace freeze plugs, either hone or bore the cylinders depending upon the cylinder checks, send the crank out for grinding if necessary. I will have them put in new main bearings and cam bearings. They will replace the valve springs and do a three angle grind. I will do the rest of the rebuild assembly myself.

So, back to the component questions. This is a daily driver so want good gas mileage with just a little get up and go. Looking for good reliable parts with long life and affordable. What brand/type (part number?) does everybody recommend for the following:

Piston Rings
Camshaft (not sure 252 or 262)
Lifters and Pushrods
Timing gear and chain
Oil Pump

I want to round up the parts so when the engine comes back I can finish it pretty quickly.

Thanks.

project89

iTrader: (1)

what do u use the car the most for ? this will determine which cam to get

the 252 cam has brute off idle tq and power great for city driving

the 260 cam moves the power range up a lil bit which is better for wot driving , it sacrifices a lil power down low in order to make more power up high

pilsbury has the 252 cam in his car and it really gets the car up and moving before the turbo kicks in

either cam and lifter set can be bought from delta for 105$'s

u want moly/plasmamoly ring set , just tell the machine shop thats what u want as they will have to have th epistons and rings on hand before they do the bore/hone job


get stock replacement oil pump for the 3.1 and pickup tube since u are using the 3.1 oil pan, the 3.4 pan is a lil deeper so the oilpump has a slightly deeper pickup tube on it

when u get the oil pump remove the presure relief spring and shim it it with a single washer then reasemmble it.

the washer in the relief valve assembly gives u a fe wmore psi of oil presure

LarryD

Sounds like I want the 252 Cam. I think based on the description that leaves the top end alone relative to freeway driving. This is truly a daily driver and much of that is at freeway speeds but then it is the Seattle area so a lot of stop and go at times and a fair amount of city driving.

I will probably buy the rings separate from the machine shop and install those myself. If I need new pistons (ie if they bore it) then I will have them install them. Will go with your suggestion on Moly/Plasmamoly...

The reason I asked about the oil pump it seems like I always have had low pressure on my current 3.1L. That sounds like the info I needed about changing the spring on it and solving that problem.

I might go with roller lifters but stay with stock rockers but not sure about the yet. Don't know if that gains me much or if roller lifters can be used with stock rockers but assume so.... May just leave it as stock lifters and rockers though..

Thinking just stock timing gears and chain.. The set in my current 3.1L are about 125,000 miles old so probably a good idea to replace them in the new engine.

Thanks for the info..

Six_Shooter

iTrader: (2)

You can't just throw in roller lifters.

The cam has to have a roller grind, they are different, even if the lobe specs appear to be the same on paper. There's also the issue of proper oiling when using roller lifters, where a roller lifter generally requires less oil. In SBC's this is easy to compensate for by using oil galley restrictors, but you can't do that in a 660, because then you will starve the cam and crank of oil. The early 660 blocks are cam priority oiling.

The later 660s that have roller lifters have a different oiling system, more like a SBC, where there are two lifter galleys, and one cam and crank galley.

project89

iTrader: (1)

the 252 will give up a lil power on the top end , but has a really strong off idle and good midrange

the 260 is a midrange/top end cam

u dont replace the spring in the oilpump u just shim it a lil bit , and trust me a lil is all u need , my 3.1 has 60psi of presure hot at idle and over 105 psi at redline. this will destroy a stock rebuild as it wont have the proper clearances to run that much presure.

alls u need is a single an washer to do it correctly. i have mine shimmed with 3 washers.
a single washer should give u 7-12 psi more then stock

fasteddi

iTrader: (2)

Mine pump has got one washer in it. 45-50 psi warm idle, pegged at high rpms.

A 260 cam is a good choice if you plan to ever open the heads up a tad. It will help flow a tad more air and keep the engine lively at higher rpms.

LarryD

Great, thanks for all the info.. Roller lifters are out then and will go with stock ones.. One thin washer on the oil pump spring then it is...

LarryD

The 3.4L is almost stripped down and ready for the machine shop. I do have a question about a sensor on the driver's side front of the block. It is on the top right in front of the intake manifold, flush with the surface of the block and with a couple of wires coming out of the top of it. There was a small bolt like a hold down on one corner of it. Took that bolt out and tried to pry it up but doesn't want to budge. Anybody know how to get that thing to come up and out of the block? It spins around but doesn't unscrew. Brute force? It doesn't exist on the 3.1 so I guess I will freeze plug that hole if I can get it out.

Thanks.

Six_Shooter

iTrader: (2)

That's the cam position sensor. Many people do replace it with a Welch plug in similar swaps.

It will slide out of the hole, they tend to get stuck because of the O-ring getting hard.

LarryD

Great, thanks.. Will just pry it out with a bit of brute force...

Any idea how to get the dipstick tube out also... Figure taking it to the machine shop that would probably get bent in the process...

KG427KG427

iTrader: (1)

is a 260 cam from delta cams california smog legal?

Cadaver Puncher

iTrader: (1)

Nothing aftermarket except tires and carpet is legal in cali.lol