LS cracks in between the Valve Seats 862’s
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- เผยแพร่เมื่อ 28 เม.ย. 2018
- I found a couple cracks in between a couple of my valve seats.
Plan A, get the heads pressure tested to see if they leak coolant, decide based on my results. If it’s cost effective I’ll get the heads repaired. - ยานยนต์และพาหนะ
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I'm glad I found your channel. My 862's have cracks between most of the valves, which really worried me, so I took them to be pressure tested, and they checked out to be good. The machinist said there's actually about a half inch or better of material under that crack so they must just be surface cracks.
My 862 heads had a crack that looked identical to yours. I had them pressure tested and they were fine. As long as the seat or down the side below the seat isn't cracked they should be fine. Love all your videos, and they have taught me alot. I ported a set of 862 by watching your videos. Keep them coming !! American muscle, LS style !!
Jimmy Mencer Thank you for the kind words and for watching I’m glad the videos are helping people. Thanks again stay safe! JD
Nice, because of this video, I was able to recognize the same for my 5.3. Thanks again, because you saved me money that I would have wasted not knowing about these now common to me rebuilding these heads mine are also 862's.
That must be frustrating, I also port ls heads and know how much time goes into them. Hope it works out for you and keep the videos coming.
lsxbc77 Fingers crossed on a good outcome! 🤞
Thanks, I’ll post up the process! 👍
My 317s have the same problem. I'm going to run them. The engine was running and there is not sign of any problems that I can see in the cylinders. My machinist said it was common and they see it all the time with Dart steel heads and they don't cause any issue with leaking.
Live To Race Exactly, these ended up passing a pressure test, superficial surface cracks are normal. 👍. Thanks for the feedback I appreciate it! Enjoy your build!
I heard the rec-port heads had this issue big-time and weren't really a problem on the cathedral-port heads like this. Then there's the Castech head crack issues on the 706 and some 862's. Sure makes it tough trying to cobble together parts to make for a bullet-proof, budget LS engine. Thanks for the video
I won’t port 706’s, the symbol looks like a sideways Battery indicates the crack prone heads. I haven’t come across any 862’s I couldn’t use.
Interesting information on the rectangle port heads! Thanks for watching and the feedback! JD
Same problem on a set of 317s. Spent hours doing full port and polish only to find when I smoothed the chambers every chamber was split. From what I have gathered from my machinist it's very common and on a n/a engine you could probably run them safely for quite awhile. On a boosted engine with higher cylinder pressures your asking for catastrophic failure. The problem being the seats will possibly and eventually loosen and dislodge. Not worth the risk for myself so I went with a set of 243 and made positive they were solid. Pricey mistake on my part.
Brandon Peery Dang that stinks! I’ll look into my repair options if they fail the pressure test. I’ve had this repaired on iron 4.3 Vortec heads before I just can’t remember the cost. 🙏🏻🙏🏻🙏🏻
Mine were the same way. I ran 26# through them with an S480 for 2 years and had no issues. And they're still running with the current owner now
they will be just fine! have ran my 862's for four years no troubles turn it 7000rpm everytime i get in it. no water seepage
Logan Penland I believe your right, after cleaning them up a little and smoothing the area the cracks disappeared. You’re not the first person to say those cracks aren’t a big deal. Thanks for the feedback I appreciate it! 👍👍👍
@@HeadFlowInc awesome bud! Loved watching your videos by the way
just discovered these same cracks on both of my 799 heads(one cyl per head) the other day after spending a whole day taking em apart and degreasing them to get em ready for some spring upgrades. Still going to run em since they will be in a car and fairly easy to get to if i ever need to swap em out. Whats weird is mine are not castech heads no castech stamping anywhere. came out of a 15 express 2500 with 199k miles. Only paid $50 bucks for whole engine so not worried at all.
Those cracks are superficial at the surface, from my research and speaking with machine shops rarely if ever do they leak unless the crack goes through the valve seat. Apparently the aluminum is very thick below the area between the valves and isn’t an issue. JD
HeadFlowInc thats a relief. Thank you for being so interactive with your viewers. You’re awesome!
If the crack doesn't run down past the seats, run them. I aswell have a machine shop and have never had them crack below.
fearing for america These ended up not being an issue, plus I’ve found this is very common but doesn’t leak coolant. Thanks for the feedback I appreciate it! JD
So did you run them or what? I just found the same crack, and did the same thing, surfaced and valve job done already, just doing final assembly.
Those heads have been in service since about 6 months to a year from posting the video. I found this surface cracking is very common but doesn’t cause an issue because the area below there is solid aluminum. JD
So what was your co conclusion?? I just found 2 on each of my heads and I just spent tons of time and money on them 😣 they're literally the same size cracks.
Hopeless Garage Mine were surface cracks only, dressing the area and smoothing made them disappear. Try using a sanding roll or something similar to work the bridge between the seats. If you still have any cracks then have the heads pressure checked. Worst case scenario they can be repaired. Good luck! 👍
I guess I'm going to run them then. My 823 heads are cracked beyond repair but I have a set of 317 heads that are cracked between the valves. Did you ever run those heads? If you did how did it turn out?
The heads passed a pressure test, the machine shop stated there’s a long distance between the surface and any coolant. As long as there’s no cracks through the valve seats themselves they should be fine. I had no idea how common this issue was. JD
@@HeadFlowInc I wish I would have known this 2 years ago. Thanks for the reply. I'm going to put them on. I'm in the process of ordering the throttle body adapter now
Y didn't you have them magnafluxed from the beginning?
Richard Harris I didn’t bother having them checked since they came of the running 4.8 out of my own vehicle.
Can't magnaflux aluminum.
That sucks !! is 862 heads and 706 heads basically the same?
Michael Reasoner Yes, the 862/706 are considered interchangeable. They say the 706’s are more prone to cracking.
Too many times I've seen heads destroyed from increasing valve size. I don't know if there is a mathematical equation to determine the amount of mass needed between the ports, my opinion is that when you get below 1/8"
between the ports your asking for trouble, especially a performance engine.
We always need to account for structural stability and port wall thickness, I agree! Thanks for watching and the feedback! JD
JD my 862 are cracked too. The engine didn't use coolant. Let me know you make out.
Mike MacCracken I didn’t see any signs of coolant in the cylinders, as in clean piston top or other.
It’s worth vacuum testing, I’ll definitely update ASAP
HeadFlowInc there was no tell tale signs on the pistons and carbon was stuck in the cracks. I noticed yours were cracked a few videos ago and figured you knew. Please keep me in the loop.
Mike MacCracken Decided to save these cracked 862’s and have them repaired later. I might put them up for sale once they’re repaired.
I’m going to finish the other set of 862’s with the upgrade to 2.00”/1.57” valves, surface .020”, and I’ll clean up the ports. I’m focused on getting the Turbo 4.8 running. 🤞🤞🤞
Awe geez man....thats one hell of a birthday present huh? 😥 Crossing my fingers that the cracks dont reach into the water jackets.
Bad Luck Garage I had a blast, Little Rock on Friday, Tulsa on Saturday, back home on Sunday! 👍
My daughter asked me, “How’s it feel being 50?”, I said “Very similar to being “49”... 😜😜😜😂😂😂
Sounds like a great b-day after all. 👍🏻 I’ll be there in 9 more years myself. 😜
JBweld dawg
Chris from family guy with an upper respiratory infection
ABarney 15 I’ve actually been told this before lol 😂 Thanks for watching! JD
You seem to have the same luck I have had
stealthhit 🙏🏻 can get the heads tested and repaired ASAP. I already missed my B-Day deadline...🙄😀
Damn. That sucks.
30hrs !!! ? Dang man!
MidwestCatz Generally it takes 25-30 hrs. It can be done faster but then I run the chance of making a mistake. 🤔
Thanks for watching! 👍👍👍
My first set of LS heads took me 25 hours and I did a lot more removing of material in the ports. He was trying to not remove a lot but improve. That’s even harder. It’s a lot of tedious work. You gata love it to do it. It’s my favorite thing to do on a engine so I don’t mind. I’m gona bang out a set of 862’s now and it’s gona be at least 20 hours.
Sorry, bad news after all that work.
JB Weld
This scares me. I think I got this. 862 head. Slow coolant loss with no apparent external leak. Excessive sludge buildup. Hmm.
You can have the head/s pressure tested. LS engines can pull oil in via the PCV system filling the intake and caking the back of the valves.
GM use to sell coolant passage sealing tablets specifically for use with aluminum heads, see if you can find them. JD
@@HeadFlowInc who generally does pressure test? Do the heads need to be removed for that? Thank you
A machine shop can pressure test the heads but they’ll need to be removed.
You might start by trying the coolant sealant.
Had mine blow a 4.8 up with water
Dylan Turner That truly stinks! Very sorry to hear the result, thank you for the feedback I appreciate it! JD
HeadFlowInc yeah man mine was in the port it self but its welded up id like to see if they hold water or what. Ive got some moroso a b putty have u used it with luck?
Dylan Turner I’ve never used epoxy but I’ve seen porters use the A&B putty to build turtles in intakes and modify areas of the ports to gain flow.
Not to be mean but you really cant port Where do you get your porting numbers all cylinders have port numbers shapes and more You can get mad and be negative if you want but you never talk about numbers because you like many u tube mechanic watch other's and think that's the right way sad sad sad i seen in many of yr video's Where you cut out all your torque just to get size lol not trying to be mean i can see you want to get the job done rite good luck Another thing it don't take 15 hours on each head sick of people saying that not even when you move push rods lol
Goodfellas Inc. wheres your porting videos?
soyramflero if you WOULD put the effort into looking then trying to be a smart ass you would see lol you cant get mad i want to help the port world like i do in the banshee world
Goodfellas Inc. you dont have any vidoes. You may want to reference another account or another channel but that wont give you any creedence. your another TH-cam surfer with an unmerited opinion judging another persons well DOCUMENTED work. do you see how people may percieve you? there's a name for that.
Goodfellas Inc. you unwittingly proved my point better than i could
chadyellowz06 good for you when you have the right tools and know what to do you get done a lot quicker i been doing port work for 25 + years and 2 stroke too