It was just a thought. If you were spinning rod bearings on the motor, stock, then, yeah, it's very possible that some oil galleries got plugged up somewhere.
I don't think heat-wrap costs too much. It should be a simple test...

 

get that 10-30 out of there, i use rotella 15-40 exclusively in any turbo motor i do.
the only exception would be if i cannot get any i would use castrol straight 40w, but thats only happened to me once cause the parts store was out and i had already drained the oil oil out of the pan

 

I'm thinkng of grabbing a 3.4 short block from the junk yard $100. The one junk yard had three motors still in cars. I talked to one of the employees. He recommended I pull a certain one because he knew it ran, he drove it into the lot, but the rear quarter was wrecked. it also had an m5 tranny. The odometer said 99K.

edit: I also plan on doing the oil system mods in the 60 degree section of the GM performance division handbook.

 

Those extra cubes can't hurt.
Will you still be running the right compression ratio? Or will you have to swap pistons?

 

I will need 3400 pistons.

 

That's what I thought, but wasn't sure.

 

its really only 9.88 cu.in extra.

Does anyone need any 3400 parts? If not, I'm going the rob the pistons from the motor and leave the rest in the junk yard to rot.

 

Yeah, I need pistons. LOL

 

hmm. The 3.4 is 204ci, not the 207 GM claims

How much they end up costing ya?

Hit me up.

 

It's still a 5% increase over the 3.1L...LMAO! Besides, who's going to say, "NO!" to MORE cubic inches?! SERIOUSLY?!

 

This thread has been an interesting read. Sucks that you've spun 2 bearings though..

 

Block, cam, timing set, lifters, crank, both sets of pistons/rods, and flywheel where $112 w/tax. The 3.4 was in good shape for 199,000 miles (missed the 1 before). Couldn't be the original motor. The 3400 had a spun rod bearing.

 

Which head gaskets do I want? Felpro, in order from least to most expensive:
9105pt (gen1 3.4L)
9071pt (gen3 3400)
9113pt (DOHC 3.4)

 

See if you can find a set of these for a 3.4 sized bore... I haven't looked for the part number for a 3.4, so I don't have it. These are MLS head gaskets that are supposed to help seal the aluminum heads better:

http://www.jegs.com/i/Fel-Pro/375/10...oductId=746458

Also Fel-Pro.

 

Yeah, these have 3.620" bore. The larger bore applications (3.4) are not offered. But for those interested, these are .039" thick compressed, with pre-flattened copper wire, and steel core laminate (not a conventional MLS). However, I went with the 9071PT 3400 gaskets. They should do fine with Al heads.

 

Here is a spreadsheet of mfg part numbers and prices from different retailers for a 3.4/3x00 hybrid engine.

 

How much, and do they offer some for the smaller bore? Also, how thick? I'm shooting for .040".

 

The ones at Jegs (Felpro performance gasket #1029) ARE for the smaller bore. Their 3.620" gasket bore is too small for a 3.4L (3.622").

 

I was referring to the ones you bought...

 

sry. Refer to the spreadsheet then.

 

The DOHC gaskets do not work on the OHV engine, FYI

 

I just popped two pistons off the rods and weighed them. The 3400 piston&pin weighs 494.4 grams. Gen 1 3.4 piston&pin weighs 535.8 grams. Are we sure balancing is not required? or am I ignorant of something? The two rods are 592.0g and 591.7g respectively.

 

Why wouldn't you balance the rotating assembly? Maybe my OCD is breaking out, again, but...WHY NOT? A balanced rotating assembly saves a lot of headaches and makes the engine more efficient as a whole. Yeah, it costs a bit, but you get what you pay for.

 

in all the talk about putting together mixed generation engines. I've never heard anything about balancing. And the money thing is a big one too, but I can't afford to do it again-again either.

 

The same crank is used in the 3.1, 3100, 3400, 3.4, 3.4 DOHC. The 3400 pistons weigh less because they have a bigger dish with the same piston dimensions.

 

Yeah, the 3.4 crank has "3.1L 981" cast into it. A replacement crank is also the same exact part number at parts stores for all of the above applications.

but the piston weight effects balancing. For 90* engines: Bobweight = rotating weight + .5 x reciprocating weight.

Is there something about the 60 degree crank goemetry that the piston weight doesn't affect balancing?

 

Not sure on that one, but if there was an issue with the weights of the pistons, people would have problems long before now. The 60v6 acts more like a i6 than it does a 90v6 due to the narrow angle. A 90* v8 has a whole different balancing scheme than either.

Yes, they are all "981" cranks, and from all that I have seen, they all have the same drilled pockets in them and after the transition during the pre85-86 external balancing, they are supposed to be "neutrally balanced".

the rods in all those applications are identical as well, I remember you saying earlier in the thread about the machine shop showing you the difference between the 3100 and 2.8 rods, but I have yet to see any variation in the dozens of 60 degree motors I have opened.

 

I don't have 6 rods that look exactly alike. The differences are in the forging dies. There seem to be a couple of revisions over time and most likely multiple mfg's with different ID numbers and markings. Then the engine building facility picks 6 rods at random and slaps them in the motor. The rods all seem to weigh the same, and fit interchangably. I haven't been back to that machine shop since.

 

I cross drilled the main journals in the crank. I also added two additional oil holes in each upper main bearing to ensure the crank gets full oil pressure over the entire 180 oil slot. These modifications are covered in the gm performance division handbook. The book explains that these modifications have been proven to proved adequate sustained high rpm’s in naturally aspirated racing applications with over 270hp for hours.

 

I finally disassembled the engine. It was the #4 rod bearing that spun. Caught it in time before it did any damage.
Its time to clean out the shed.
300ish miles on the motor. 2.8/3.1 Block and crank and some other little stuff for sale... $25 if you can come get it all. The pistons are also for sale: $75 They are hyperuetectic Mahle 3100 pistons, .75mm oversize, coated skirts, perfect condition, w/ rings, rings not even seated yet. I have a bunch of connecting rods too, make an offer.

 

pistons $75obo

 

the timing chain guide from the 2.8 doesnt fit the 3.4 block because the 3.4 block doesn't have a counter bore to locate the guide like the 2.8 block.

 

What?

The timing chain guides most certainly are interchangeable, since well they both use the same guide.

 

Actually it doesn't despite the common PN. I ordered one for my 3.4 and it had the dowel on the right bolt hole like the 2.8 guides, but the 3.4 block doesn't have the locating hole. WTF? I had to grind the dowel off to use it.

 

I had my brother grind it off while I torqued the heads.

 

I haven't figured out why or what is different yet, but the pushrods are roughly 1/8 too long now. I marked each lifter, pushrod, and rocker and put them exactly where they came from. The only thing different is the block. Do the tops of the 3400 pistons normaly stick out of the 3.4 block slightly at top dead center? the motor turns over easily by hand with the heads torqued.

 

Research would do you wonders...

The 3400 pistons come proud of the deck surface by .020".

What pushrods are you using?

 

Thanks, I thought is was .020" above the deck, I just wasn't sure I was remembering correctly, its been awhile. I'm using pushrods for a 91 V6 cavalier, they worked fine on the 2.8 block (aka 3.1/3100). I transferred those exact parts from the old block to the new one in exactly all the same places as before. Same heads, everything. Last time the pushrods only preloaded the lifters a little bit when the studs were torqued. Now, the valvespring compresses a little bit.

 

Are you installing the pushrod on the heal of the lobe?

It is also important to measure and get custom length pushrods when building a hybrid due to some inconsistencies there seems to be.

 

I have the #1 cylinder (front passenger side) at top dead center (and 360 degrees away) and only checked the valves that are closed at each instant. It seems like custom pushrods are needed. I don't know what else could be the problem.

 

There's alot of variation between various rwd blocks for some reason. I'm guessing they may have lowered the cam tunnel slightly on late motors because '92 cavalier pushrods worked (not great, but they worked) on my '94 3.4 block when I had the stock 2.8 cam in. I'd like a definitive answer on this too.

 

I did some checking and measuring and comparing between the two blocks. the blocks are identical as far as I can tell. The angle between deck surfaces are both dead on 120* to the best I can measure. The lifter bores are the same distance from the machined surface on the front of each block within +/-.005". The deck hieght is the same to the best I can measure +/-1/16" and the piston TDC seems close to the theoretical .020" above the deck.

I dissasembled and cleaned a lifter to be sure it would compress easily. I moved the lifter around to different bores and measured how much it compressed when the rocker stud was tightened. In order to measure how much it compressed, I counted the turns of the rocker screw from zero lash untill the rocker-pedestal was flat against the head. I didn't torque it to keep bolt stretch out of the equation.

The rocker screws have M10-1.50 threads, therefore, the intake valves compressed .074" (1-1/4 turns) and the exhaust valves compressed .089" (1-1/2 turns). So they're not as bad as I thought, but it might as well be a mile. According to Chilton's, the lifter is only supposed to compress 1-1/2 turns on an iron head motor (that is .059" on the M10-1.0 rocker stud). Is that correct?

I found a set of used SBC lifters which have the same diameter and overall length, but the retaining ring looked deeper into the lifter body. I popped one of those in and re-did the same tests. The intake compressed 3/4 turn (.044") and the exhaust compressed 1 turn (.059"). This sounds perfect... BUT... a SBC lifter only compresses .030" to be in the center.

conclusion... the intake pushrods are .015" too long and the exhaust are .030" too long.

 

doing some research... 92 cavalier pushrod lengths are:

-Melling #MPR-375 (intake) 6.043"
-Melling #MPR-376 (exhaust) 6.390"
-FM #BRP3273 (intake) 6.042"
-FM #BRP3274 (exhaust) 6.389"
*measured what I have (intake) 6.046"
*measured what I have (exhaust) 6.399"

So what is the ideal amount of preload on the hydraulic lifters? I've done a little research and it seems like (in theory) it doesn't really matter... since they self-adjust to zero valvetrain lash and "stick" at that length.

It seems I need something 6.370ex/6.031int for 1.5mm preload or 6.341ex/6.002in for .030" preload. However, I've read 6.250ex/5.950int suggested on the 60v6 forum a few times. A ford 302 push rod is 6.250" long and has the 5/16 ball and tube. Any suggestions?

 

So you have the early 3400 heads with the 10mm pedestal bolts, I gather?

~.060" is stock for the 3x00's.

What cam do you have? Since most of the cams are designed for the flat tappet and adjustable rocker arms, they aren't as an exact science as a roller cam would be. I have had some that worked with the Cavi p-rods and some that didn't. Seems as though a particular cam profile we sell a lot of works across the board, though, always ordering from the same cam grinder.

 

I pulled the heads from a 2000 Malibu 3100. The cam is the 212/212@.050" .440"/.440" flat tappet. I think its the comp260 (not a regrind). Literally the same cam I used before.

 

Comp Cams recommends lifter preload of .030" to .060". I made an adjustable pushrod to determine what length I would need. Using 60v6 lifters at zero preload and zero lash the exhaust pushrod was 6.250" actual length (kinda lucky that it came out even). That calculates to 6.233" gauge length using a .140" gauge. Therefore, to obtain .030" to .060" of lifter preload I need a pushrod with a gauge length between 6.263" and 6.293".

The intake pushrod measured 5.925" actual length at zero/zero. That calculates to 5.908" gauge length with a .140" gauge. Therefore I need a pushrod with a gauge length between 5.938" and 5.968".

Suppliers stock "universal pushrods" in .050" inch increments starting at 6.000". Unfortunately none of them fall in the ranges I need.

Through a bit more research I found that Ford 3.0L engines from the late 80's used 5.960" gauge length pushrods. That gives me .052" preload on the intake lifters.
MFG Part Numbers:
Clevite/Mahle: 215-4245
Federal Mogul/Sealed Power: rp-3281
Melling: MPR-377

For the exhaust pushrod I can only find 3 options.
1. Use a 6.250" gauge length pushrod and live with .017" preload. Comp Cams #7621-1.
2. Use a 6.300" gauge length pushrod and have .067" preload (possibly shim the rockers a little bit).
3. Buy a custom made set of pushrods for more money than I'm willing to pay.

 

What do you mean by "gauge length?"

 

Gauge length is like using a micrometer with a .140" hole drilled in each end where part of each pushrod tip goes inside each hole. That's the best analogy I can think of. The purpose of guage length is for consistant measurement technique by taking the oil hole out of the measurement.

 

By golly, I think he's got it.

 

Just FYI, the 5.96" pushrod tips (3.0L ford app) mic about half-a-thou smaller diameter than the 91 cavalier 6.042" pushrod tips. One is Speed Pro, the other is an unknown brand (I forget), respectively. The preload averages .047" on the intake valves. The jury is still out on what to do about the exhaust pushrods. I'll probably order 6.250" universals and settle for ~.017" preload.