Oil advice for quieting Forged piston slap/noise

[Blackcountryboy]

Hey guys

As the title says im looking for some advice please for quietng my forged rebuild. It literally sounds like a diesel tractor lol.

The bore to wall clearance was roughy 5k on all pots (Ross pistons spec is 6k) so its not crazy loose.

On the 1st build i used meaty thick Hastings iron rings and had v little noise. On this building (my 2nd ever, still v new at this) I Used Accrilite rings which where thinner n not at beefy looking and they slap like fook.

Compressions good and shes running on all pots now.

Engines only got an hours run time on it using cheap mineral oil and have changed 2 oil filters since running in at 2k rpm.

Cars not road legal at the minute so as soon as it is and has done 500 or so miles what oil should I go for to quieten her a bit?

I'm using Ross 86.5mm pistons, with eagle rods and accrilite rings if that helps at all. Its a hybrid rev 2/3 3sgte.

Will try n post a video

Thanks again

Chris

[Blackcountryboy]

Anybody?

Forged pistons + 3sge cams + solid engine mounts..... Sounds like a sewing machine at idle....

All shims are in spec?

A pal of mine reckons the tubular manifold "amplifies" the tap/slap?

Thanks again.

Chris

[oldcorollas]

Does it get quieter when it's warmed up?

[Blackcountryboy]

Hey thanks for the reply., it seems to sound a bit clackety hot or cold. It doesnt go away really warmed up. Running a huge ally rad with water wetter so doesnt really get hot (so far without properly driving her yet).

I've tried adding NF octane booster as its quite a high compression build (head was skimmed once before I bought the project engine to build, guy couldnt remember by how much when I asked but he assured me it was only lightly skimmed. Combined with 9.0:1 pistons and a 1mm comettic HG torqued to 70ft/ib using ARP studs i estimate it to be close to 9.4:1 ... So my first uneducated assumption was it was pinging a bit on 99 octane juice. I also checked the timing was bang on 10 btdc.

Still clackety....

Thought maybe the knock sensor was bad or the tap happy cams where upsetting it but I turned it off below 3k (link ecu)... Still runs like a tractor.

Checked the valve clearances, all in spec and I assumed the valvetrains noise cos the inlet cam is a fast ramp high lift cam (3sge na 252/9.8mm). I chose this cam for the street with the GT2860RS.

Played with the cam timing too till I got 19-20 hg cold idle.

Clack clack clack...

Tried using that Lucas stabiliser crap (please don't blaze me lol). Bit better but still sounds like a diesel.

Checked for vac leaks a trillion times. She starts, revs but I just can't work out for the life of me why she sounds sh*tty at idle.

Actually sounds like a beast 2000-3000rpm (as high as I dare rev her before shes RR tuned)

All idlers, gaskets, are new. ONLY thing I reused was the "new" tensioner. Cambelt has no play in it.

Tried to upload a video on youtube last night for you guys to tell me what you think (ridiculous just by sound i know without seeing) my phones not playing ball either.

My question is.. I know Wiseco pistons are supposed to be loud but any of you guys run ROSS pistons? Ifso at specced bored clearances where they still loud?

Gonna play the timing this week, clean the plugs and maybe try even some thicker oil?

Got 60+ psi cold oil pressure n when I checked the cam clearances theres def oil getting up there...

Sorry im rambling, work nights n not had my full quota of coffee yet!

I'm determined not to give up on this puppy!

Thanks again

Chris

[Blackcountryboy]

https://youtu.be/EBvaz28de7g

[Blackcountryboy]

When I say I added some octane booster was just a bit. Might try a whole bottle with more fuel tmrw n pull the timing to 8 btdc. In the video it knocks more under load as I pull backwards n forwards. Slap? Pinging?

Thanks

Chris

[jondee86]

Sounds like an exhaust leak to me. A small gasket leak can sound exactly like something mechanical ticking.

And although I didn't hear "knocking" you shouldn't be getting any knock at idle or low revs/no boost. And certainly not at 10deg BTDC. If you are recording knock the sensor is most likely picking up mechanical noise. My engine does that... sensor picks up a huge amount of knock at 1500rpm and then tapers away as the revs go up.

Cheers... jondee86

[Nevakikamukau]

Sounds "gudgeony" to me.

Cheers Pete

[Blackcountryboy]

Hey

Thanks for the input again Jon/Pete its appreciated.

Bought a stethoscope on fleabay last night to try and track it down.

Hope your right Jon, I don't fancy pulling the engine to change the gudeon pins!!!

I just think it sounds really rough dog rough. I can live with the clackety idle if she goes like stink tho lol.

When you turn the video up you can hear it "knock" as I pull backwards and forwards. Been reading detonations more noticable at low rpm/load than high rpm/load?!?!? Is this BS? or for real?

My wideband reads rich (cant be lean knock), plugs are black and the J&S knock meter I have fitted doesn't hear anything?

I just audibly hearing that knocking as I pull away gentley. Give it some bean and it almost goes away if that helps?

Thankyou once again everyone for taking the time to read, watch and give me your thoughts, none of my mates are into cars or engine building you guys on Toymods are absolutly GOLDEN!, one day im gonna get this car finished ; )

Cheers

Chris

[oldcorollas]

Sounds like an exhaust leak to me. A small gasket leak can sound exactly like something mechanical ticking.

And although I didn't hear "knocking" you shouldn't be getting any knock at idle or low revs/no boost. And certainly not at 10deg BTDC. If you are recording knock the sensor is most likely picking up mechanical noise. My engine does that... sensor picks up a huge amount of knock at 1500rpm and then tapers away as the revs go up.

Cheers... jondee86

That change in clack sound, as it goes from revs going up, to revs going down, could be leak..
I'd be getting a piece of pipe and waving it around all exhauast joins, including manifold welds..

Dumb question.. the rings were the right thckness and depth for the grooves? Installed correct way up?

[Blackcountryboy]

Think you might be on to something I'll get some pipe and check tmrw. Id sealed up the manifold to head with exhaust sealant but I'll double check.

The first set of rings i used where Hastings iron rings 1.5/1.5/3.0mm but on the second current engine i used Acrilite rings they where'nt as beefy 1.2/1.2/3.0mm but fit good and didnt wobble or move so I thought theyd be ok.

Could this be my problem you think?

Def made sure they where all in staggered dots face up. 180 - 190 on allpots and diesnt seem to burn oil all all.

Low rom/light load knocking just doesnt make sense.

I plastigaged all the bearings and the checked the bore clearances which where in spec for the forged pistons i used. Wonding if Ross pistons have a centre or offset pin design and that why its so clackety if anybody knows?

Thanks

Chris

[jondee86]

I'm not sure that fitting a thinner ring in a groove made for a thicker ring is a good idea. Rings are supposed to be fitted with a certain axial clearance, sufficient to allow the ring to function correctly, but not so much as to allow the ring to move excessively. If the 1.5mm rings were the correct thickness for the grooves, was there any unusual noise from the engine ? If the noise only became apparent after the 1.2mm rings were installed, perhaps that is part of the problem.

This table from Wiseco linked below contains their recommendations...

https://cdn2.hubspot.net/hubfs/22979...=1522099364034

I don't actually know exactly what the noise/mechanical/performance downside is from fitting rings with excessive axial clearance, but I'm pretty sure the long term effects will not be good.

Cheers... jondee86

[JustenGT8]

Can you check the oil flow to the head? Cam buckets cam sound like that with poor oil supply....what head gasket did you use?

I need a better speaker but the more I listen to it I'm thinking its a valve train noise

[Blackcountryboy]

Hey all,

Thanks for the replies

Never thought about slightly thinner rings being noisier, but they may well add a lot to the overall clatter. The other thicker brand even tho cheaper seemed "sweeter" sounding.

More and more I think about it Jon I wanna pull the head and sump and change the rings n fit a thicker HG as these are the only 2 things that changed when I rebuilt the motor. I also swapped out the 9mm lift HKS inlet can for the 3sge 9.8mm lift can. The old engine was loads quieter...

The old HG was 2mm Cometic this ones a 1mm Cometic HG.

First build was a big gt3082r turbo low compression build. After spinning a bearing racing "Mr Burns" in bentley Continental one night on the way home from work (engine hadnt broken in fully, damn my right foot!) I went the other way instead, high compression disco potato n this engine sounds like crap compared to my first attempt.

I should really just leave it to the pros who know what their doing but building it month by month part by part every payday is just SO MUCH FUN.

Gonna go play with her now if I don't get rained off. Gonna add some octane NF booster n exhaust leak/noise hunt. Will try n post another more detailed video tonight.

Thanks again

Chris

[oldcorollas]

these 86.5mm pistons? http://www.rosspistons.com/product/t...-4-90cc-99823/

Piston Top Type: Dish Top
Bore: 3.406(in) – 86.50(mm)
Stroke: 3.386
Rod Length: 5.428
Head CC: 50.0
Compression Height: 1.380
Compression Ratio: 8.50
Dome Volume: -4.90
Gram Weight: 370
Rings: 1.5 1.5 3.0
Rings Included: Yes
Pin Type: 52100 Bearing Steel


so 1.2mm ring in a 1.5mm slot = extra 0.3mm side clearance = extra 0.0118" = 5 to 10 times too much clearance??

i dunno what clearance Ross recommends but..
http://www.enginebuildermag.com/2017...pistons-rings/

Side clearance between the ring and piston groove is easy to measure with a feeler gauge. Most rings for performance applications require .001 to .0015˝ of side clearance. Some original equipment engines may allow as much as .002 to .0025˝ of side clearance for the rings in their grooves. It all depends on the application.


struggling to find which accralite rings you used??