fwd roller and non roller cam parts in gn motor w/pictures
- Thread starter 87buickracer
- Start date
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
Has anybody determined what the max cam lift with this system is?
A.j.
A.j.
87buickracer
Member
- Joined
- Dec 2, 2004
My motor is done..waiting for car to come back from bodyshop with roll cage.My next motor with have all high dollar parts with steel rotating assembly,caps,girdle,big roller cam and comp roller lifters with champion intake and cnc full race heads.This was just something I wanted to do different for now.My future plans is to build a big block turbo motor when I find another car,but for now I have enough on my plate.I have the article for the cross drilling..when I have the time I will make copies and can mail it to you.Once we get the motor in and fire it up I will post back my results.Will post some pictures soon of complete engine..
"More Boost"
Major Member
- Joined
- Feb 13, 2005
i was reading this and getting all excited about doing this to my 4.1L. but when i looked at the lifter valley, it is tottally diff. than 3.8L. it's not solid like 3.8, its kinda open like a pontiac V8. idt it will work for me....
Also, the guy that was worried about tearing down his engine to drill, there needs only two small holes, and they dont even penetrate thru the valley. if u use a big blob of vaseline where u are drilling it will hold the shavings. this works very well. but then again there is no 100% way to know exactly. (my 2 cents)
Also, the guy that was worried about tearing down his engine to drill, there needs only two small holes, and they dont even penetrate thru the valley. if u use a big blob of vaseline where u are drilling it will hold the shavings. this works very well. but then again there is no 100% way to know exactly. (my 2 cents)
joe_schindler
Living better with carbon
- Joined
- Oct 1, 2001
87buickracer:
I’d really like to see what your friend had to say about cross-drilling. I’ve had some cranks done; but the jig they used didn’t always keep things square. I can send you a SASE if you let me know your address; or you can scan and email to me at:
netpay@swbell.net
More Boost:
The 4.1 is like the 14 bolt oil pan 3.8. You might be able to rig something that just hooks through the lifter valley and holds the spider down. As far as drilling inside a motor; the Vaseline trick (or pile of grease) will work; but it doesn’t take much trash (and this would be cast iron chunks) run through a Buick oil pump to kill it. Not too big of a deal on a Chevy; with an $18 oil pump; but the gears survive on the Buick; but the expensive front cover dies.
I’d really like to see what your friend had to say about cross-drilling. I’ve had some cranks done; but the jig they used didn’t always keep things square. I can send you a SASE if you let me know your address; or you can scan and email to me at:
netpay@swbell.net
More Boost:
The 4.1 is like the 14 bolt oil pan 3.8. You might be able to rig something that just hooks through the lifter valley and holds the spider down. As far as drilling inside a motor; the Vaseline trick (or pile of grease) will work; but it doesn’t take much trash (and this would be cast iron chunks) run through a Buick oil pump to kill it. Not too big of a deal on a Chevy; with an $18 oil pump; but the gears survive on the Buick; but the expensive front cover dies.
update on mine.
I got mine fired up for the first time tonight.... I am running near .590 lift on the intake...... 65 psi idling with the engine at 130 deg......motor sounds great..... but by 200 deg temp.... my oil pressure is in the ditch... down around 5 - 10 psi....
I'm wondering if this is a lifter issue?
It is a shielded foot lifter... but because I am running so much lift.... I am wondering if the body is traveling and uncovering the oil passage... and the motor is hemmoraging.
The stock 60 deg V6 lifter is a shielded foot lifter.... so I wouldn't think it would be hemmoraging......but wonder if the Johnson.... or the Comp 885 lifter body has the oil band at a different height.... or something else possibly different.... that might fix my oil pressure issue.
Anybody else running yet with a high lift cam... and the factoy 60 deg V6 lifters?
I got mine fired up for the first time tonight.... I am running near .590 lift on the intake...... 65 psi idling with the engine at 130 deg......motor sounds great..... but by 200 deg temp.... my oil pressure is in the ditch... down around 5 - 10 psi....
I'm wondering if this is a lifter issue?
It is a shielded foot lifter... but because I am running so much lift.... I am wondering if the body is traveling and uncovering the oil passage... and the motor is hemmoraging.
The stock 60 deg V6 lifter is a shielded foot lifter.... so I wouldn't think it would be hemmoraging......but wonder if the Johnson.... or the Comp 885 lifter body has the oil band at a different height.... or something else possibly different.... that might fix my oil pressure issue.
Anybody else running yet with a high lift cam... and the factoy 60 deg V6 lifters?
dr_frankenstein
Mad Scientist
- Joined
- Mar 17, 2008
I would think if you had passed the point to where its leaking, then the lifter would be far enough out of the block to start causing dog bone problems. its limited to the clearance the slot on the lifter provides - so if one lifter moves that far out i would think its twin in the dog bone would rotate and kill the cam.
Unless you have indeed found the lift limit of the factory system..... I have heard in the factory roller SBC system were limited to a max of .540 lift.
but if it was a lift problem, wouldnt it have been apparent during assembly?
A.j.
Unless you have indeed found the lift limit of the factory system..... I have heard in the factory roller SBC system were limited to a max of .540 lift.
but if it was a lift problem, wouldnt it have been apparent during assembly?
A.j.joe_schindler
Living better with carbon
- Joined
- Oct 1, 2001
I got mine fired up for the first time tonight.... I am running near .590 lift on the intake...... 65 psi idling with the engine at 130 deg......motor sounds great..... but by 200 deg temp.... my oil pressure is in the ditch... down around 5 - 10 psi....
I'm wondering if this is a lifter issue?
I kind of doubt it's the lifters; at least the lifters alone. An easy check would be to run some 40w50 and see if that helps the hot idle oil pressure. If so; I’d suspect the main and rod journal clearance. If the pressure is still low; it may be the lifters.
You’re in some uncharted territory here; as the cams and lifters in this setup weren’t made to run together. There’s probably a lot of casting shift and machining clearances that could be ignored when you ran a small flat tappet cam that you can’t with the high lift roller cams and stock style roller lifters.
You could pull the intake off and use a drill to prime the oil pump and see where the oil comes out. You might even be able to rig a compressed air line into the oil pressure sender and see where the big leaks are.
Good luck,
Joe
mikestertwo
Well-Known Member
- Joined
- Sep 13, 2006
I'm running the 60* V6 lifters with no issues. My oil pressure is 30# hot at idle with 10w-40w oil with a booster plate. The lift on my valves is only .490 with 1.55 roller rockers though. When taking measurements I found running a cam with much over .520 valve lift the flats on the lifters were reaching their limit with the dogbones but I machined the tops of the lifter bores also to make them perpendicular to the bores which gave me a little less to play with. Do you know what the base circle diameter is of the cam your using?
I was concerned about lift as well.... best I can tell.... the base circle must be smaller.... therefore allowing the lifter to go further down in the bore.... I didn't have any issue rolling the motor over.... lifter shoulder never contacted the dogbone that I could see.
I am thinking at this point it isn't a lifter issue... it is likely either bearing clearnaces... or oil pump clearances. I have a few things I am going to try before I decide to pull it.... I am going to go to a heavier oil for starters... to see if I can get hot idle pressure up. Running presure is fine.... by 2000 RPM's she is close to 60 psi... even when hot and a 5 psi idle.....
Engine under 160 deg... pressure is 40 psi +.... but once it runs enough to kick the fans on a couple times... idling (fans cut on at 205 deg)..... idle pressure is a little below 10 psi.... like 5 or 6 psi..... tickle the throttle it shoots past 40 psi quick...
I got mine fired up for the first time tonight.... I am running near .590 lift on the intake...... 65 psi idling with the engine at 130 deg......motor sounds great..... but by 200 deg temp.... my oil pressure is in the ditch... down around 5 - 10 psi....
I'm wondering if this is a lifter issue?
It is a shielded foot lifter... but because I am running so much lift.... I am wondering if the body is traveling and uncovering the oil passage... and the motor is hemmoraging.
The stock 60 deg V6 lifter is a shielded foot lifter.... so I wouldn't think it would be hemmoraging......but wonder if the Johnson.... or the Comp 885 lifter body has the oil band at a different height.... or something else possibly different.... that might fix my oil pressure issue.
Anybody else running yet with a high lift cam... and the factoy 60 deg V6 lifters?
how's it sound?
Sounds pretty good. I hear a little valvetrain noise.... but not much....the cam has a real aggressive lobe....so it is probably more noisy than a more civilized grind. I would expect it to make a small amount of valvetrain noise.
I am going to try some 20W50 tomorrow night. I am also getting the audible knock detector going off during cranking.... and if you rev it any... in park. I didn't torque it to any specs... I really tightened it pretty good....I understand these sensors need to be torqued carefully and accurately... to insure proper operation..... I feel my torque method I used.... doesn't lend itself for the thing to work properly.
joe_schindler
Living better with carbon
- Joined
- Oct 1, 2001
Is this a completely new build? If so; your pressure at idle should be above 10 PSI. If; it’s an older engine, extra low idle speed for that cool sound, or you’re intentionally running larger bearing clearance; 5 PSI is pretty common. The Buick oil pump is about as poorly engineered as possible and a lot can go wrong with it. Luckily; there’s almost no load on the engine at idle. It will most likely live for a long time like that. Make sure your idle speed is with in spec.
Not completely new....it is an SG1 109 crate engine I found in the junkyard.... std/std turbo crank...... I had it polished...... I'm checking with the builder to see what clearances were exactly..... I remember them around .002 or a little under, however that was over a year ago when the motor was built. The bearings were brand new obviously....oil pump has the melling high volume spacer and longer gear...so it should be really pumping the oil....
According to my builder... yes..... he starts off with the thinnest shim/gasket.... if gears won't turn.... he puts the thicker one in... tries again....once the gears will turn... he then figures out exactly what shim/gasket he needs to get the proper endplay.
I'm not sure what endplay he set it up to.... but he did go thru the above procedure......
I'm leaning more and more toward bearing clearance.
Crank was out mf my junkyard SG1 109.... that was standard-standard.... I had it polished.....my guess is my clearances have exceeded .0025 now.... and the pump can't keep up at idle....that is just my hunch.
I am leaning toward pulling the pan tonight (in-car) and plastigauging the clearances and see exactly what I am up against.
Maybe I can slide some .001 bearings in it? or a mixture of .001 and standard bearings.
Getting OT...... sorry.
New...
Engine was completely disassembled...cleaned... shot blasted...vatted...decked... bored....steel main caps added... line bored.... the whole enchilada....new freeze plugs...new bearings and rings throughout....
joe_schindler
Living better with carbon
- Joined
- Oct 1, 2001
2 thousandths of an inch should be about the upper limit for rod and main clearance (but you better look it up). Don’t forget to check the crank thrust play. These engines seem to chew up the cranks rather than the bearings.
Make sure your idle speed is high enough. I think these engines spec’ed at 40 PSI @ 2500 RPM (better look that up also) as the pumps just can’t pull oil out of the pan at low speeds.
If you’re changing bearings; I think 350 Buick rod bearings will fit; but are a little wider than the 231 (yep; look that up also; there may be a listing for V-6 HD bearings). If the thrust surface is eat-up; you can get an oversize bearing for that; but it requires the crank coming out. It will come out the bottom; but I don’t recommend it. Pulling the engine is easier. If the crank is out; rather than cut it for an oversize thrust; you could get it built up for not much more money.
Make sure your idle speed is high enough. I think these engines spec’ed at 40 PSI @ 2500 RPM (better look that up also) as the pumps just can’t pull oil out of the pan at low speeds.
If you’re changing bearings; I think 350 Buick rod bearings will fit; but are a little wider than the 231 (yep; look that up also; there may be a listing for V-6 HD bearings). If the thrust surface is eat-up; you can get an oversize bearing for that; but it requires the crank coming out. It will come out the bottom; but I don’t recommend it. Pulling the engine is easier. If the crank is out; rather than cut it for an oversize thrust; you could get it built up for not much more money.
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