Search found 270 matches
- Wed Oct 19, 2022 7:59 am
- Forum: Engine Tech
- Topic: Sbc Dart SHP rear main leaks
- Replies: 15
- Views: 1908
Re: Sbc Dart SHP rear main leaks
We take a piece of rubber bout 1/8 thick x 1” x 4” with bout .1/8 hole in middle then fold it around the oil drainback slot on rear cap. Use a rubber tip blow gun and air up the drainback slot and check the seal with soap bubbles. Easier with 2 people but can be done by yourself. We check as soon as...
- Thu Dec 02, 2021 8:53 pm
- Forum: Engine Tech
- Topic: Methanol or water in crankcase?
- Replies: 14
- Views: 2096
Methanol or water in crankcase?
I’ve been building methanol sprint engines for over 30 years, with much success I might add. However I just ran into a situation that I thought was water in the crankcase. Pukey looking oil EVERYWHERE on tear down. We did multiple tests on the cooling system, including heating the now long block to ...
- Thu Feb 18, 2021 8:22 pm
- Forum: Engine Tech
- Topic: aluminum spray from detonated piston
- Replies: 14
- Views: 1303
aluminum spray from detonated piston
What's the easiest way to remove aluminum spray from iron sleeve? I'm not planning on taking engine apart. I have the affected piston out and when I get most of the spray out I'll hone the 1 hole. We know why it detonated. It's an aluminum block w iron sleeves
- Sat Mar 28, 2020 8:16 am
- Forum: Engine Tech
- Topic: Unsure what to do with 0.0020" Main Clearance
- Replies: 66
- Views: 7076
Re: Unsure what to do with 0.0020" Main Clearance
Way back sometimes we would have to sand the backs of bearings on Indy car engines NO bull. All 3 cars finished Indy 500, best was 3rd. Hokie? Yes it is. Did it work? Yes it did. One could look at it as, just get to where you want it. It matters not how.
- Tue Nov 26, 2019 7:47 am
- Forum: Engine Tech
- Topic: Oil drainback holes in pistons
- Replies: 9
- Views: 2363
Re: Oil drainback holes in pistons
I’ve tried to get pm sent to no avail. Anyway I’ve done much research on this matter and the conclusion is that the holes are to large .125 and 3/32. Exacerbating the issue is holes are evenly divided above and below the bottom shelf of the oil ring groove. A large span of 1/8 inch for the scrapers ...
- Thu Nov 21, 2019 7:46 am
- Forum: Engine Tech
- Topic: Oil drainback holes in pistons
- Replies: 9
- Views: 2363
- Sun Nov 17, 2019 10:50 am
- Forum: Engine Tech
- Topic: Oil drainback holes in pistons
- Replies: 9
- Views: 2363
Re: Oil drainback holes in pistons
Unregulated vacuum, 2-.062 breather holes.
4 on major and 4 on minor thrust sides.
4 on major and 4 on minor thrust sides.
- Sat Nov 16, 2019 8:02 am
- Forum: Engine Tech
- Topic: Oil drainback holes in pistons
- Replies: 9
- Views: 2363
Oil drainback holes in pistons
Does anyone here have any oil ring opinions on efficiency differences between split oil return holes vs all the return holes in the root of the oil ring grooves? I’ve had a couple of bottom scraper rings get caught on the split return holes. Therefore bending them hence oiling the spark plug a tiny ...
- Wed Apr 17, 2019 7:15 am
- Forum: Engine Tech
- Topic: Weird SBC 350 oil leak
- Replies: 16
- Views: 3536
Re: Weird SBC 350 oil leak
Put slight air pressure in crankcase <2psi perhaps in valve cover pcv hole and check with soap bubbles and you’ll find your leak.
- Wed Oct 31, 2018 4:27 pm
- Forum: Engine Tech
- Topic: full counterweighted crankshafts???
- Replies: 21
- Views: 3647
Re: full counterweighted crankshafts???
I won't disclose crank manufacturer. Yes the car has been in 2 or 3 violent flips so it is plausible the rear tires hooked the ground loading and unloading the motor violently. The crank has 2 large pieces of Mallory in both #1 and #6 counterweight. I would guess and it would be only a guess that it...
- Wed Oct 31, 2018 11:22 am
- Forum: Engine Tech
- Topic: full counterweighted crankshafts???
- Replies: 21
- Views: 3647
full counterweighted crankshafts???
I broke in 2 a crank behind #4 rod. There was no oiling issue, many of the bearings could be reused and show no sign of detonation. Upon magnaflux inspection there were 10 additional fractures. This is a sprint engine SBC. 3.800 with 30 shows. I have multiple engines that have well over 100 shows an...
- Tue Sep 18, 2018 8:07 am
- Forum: Engine Tech
- Topic: Rocker bearing failures
- Replies: 13
- Views: 2399
Re: Rocker bearing failures
410 sprints, rpm 8400 some as hi as 9000 on occasion, .440 lobe 1.70 or 1.75 ratio, no oil restrictors, 7/16 .165 pushrods, I have so many customers on oil sponsorship that each uses a diff brand. When the cars are hooked up the low rpms for a lap will be 5800/6200 and the highs the aforementioned 8...
- Sun Sep 16, 2018 7:24 pm
- Forum: Engine Tech
- Topic: Rocker bearing failures
- Replies: 13
- Views: 2399
Re: Rocker bearing failures
Alum rockers. I doubt valve float I use soft lobes all ti valves. It could be the substrate we have less issues with steel rockers. I’ve spent a lot of time and finally found a bearing supplier that sells full compliment in the specs I need. Keep in mind every peer that I’ve contacted that uses this...
- Fri Sep 14, 2018 8:15 am
- Forum: Engine Tech
- Topic: Rocker bearing failures
- Replies: 13
- Views: 2399
Rocker bearing failures
Every year we have had to replace multiple rocker arm shaft bearings this year seems worse. Does anyone have much experience using a full compliment bearing over a caged bearing for same application? Seems like there would be more surface area both in number of needles and length of needles. Hence m...
- Mon Jul 02, 2018 10:01 pm
- Forum: Engine Tech
- Topic: Idea for pre lubing oil galleries
- Replies: 34
- Views: 5251
Re: Idea for pre lubing oil galleries
On dry sump sprint cars with. Front cam driven opumps. We put 2 gts in a goodson preluber then put shop air in tank. Connect to gauge fitting and turn motor backwards for oil to go around pressure gears and start filling the tank. We use a screwdriver next to to our ear and hold it against the prelu...