asdfqwer426

Hello, first time posting. a few weeks ago my civic with a D16Y7 in it had its timing belt break. One of the bolts for the engine mount that are under the timing cover loosened and the other snapped off and got wedged against the belt until it wore through and broke.

I haven't taken the head off yet, but i'm curious if its ok to lap in new valves? I've rebuilt old motorcycle engines from the 70's (actually, all honda's) and lapping was fine, but i've read that some newer engines have a hardened surface on the valves that will be ground off with valve lapping.

I was curious if these honda's had that hardened surface that will be damaged by lapping?

also, any advice or things i should look out for as i replace my bent valves?

Thank you.

B_Swapped93

I had a simmilar issue except it was a timing belt cover bolt with my GS-R except i was spinning the engine by hand after a spring and cam install so i didn't damage anything(except the belt). Here's a vid on how to lap them

asdfqwer426

thanks for the video, I appreciate the help. I've actually successfully lapped valves before, i was just curious if it was ok to lap valves with this engine, I assume since you've done it and the video is showing on the exact same head that it's all good to lap up this engine?

B_Swapped93

Yes you'll be fine to lap them. I've done it on several D-series engines. didn't dout you'r know how just wanted to show that it was fine to.

slowDB7

what is valve lapping? ive heard it before but dont know what it is

Emeraldbomber

IIRC its putting this compound on the valve and turning it in its seat? I helps for better surface mating

JKing106

Lapping is grinding the valves in their seats so they sit as flush as possible when closed.

B_Swapped93

watch the vid

slowDB7

i had watched it before i posted, i just didnt understand it....but now i do

89 SI zero

where would i be able to get some of that valve lapping compound?

89 SI zero

that vid is great. do you think you can post a vid on how to adjust valves? i have my head off and i think the valves are a little noisy. would they need to be adjusted?

B_Swapped93

you mean valve lash correct ? i don't know what engine you have either

asdfqwer426

awesome news, thanks again B-swapped

you can buy compound at most auto stores, as well as the wooden dowel suction cup tool. it doesn't take much compound to do a valve. a tube will likely last you a while.

back in the day when valve lapping was much more common they sold the compound in different grits, so you could get it close with more gritty compound and then finish it with a finer compound, i haven't been able to find a modern supply of compound that comes in different grits.

for setting the valves, you measure the gap between the rocker arm and the end of the valve. using a feeler gauge,you adjust the nut on the end of the rocker. BUT you have to make sure the engine is at the right point, so that there is no pressure on the rocker from the cam. be sure to measure again after you've retightened the nut as it can sometimes rotate the center piece too.

make sure to look up the exact gap for your engine, typically the exhaust and intake will be different values. the exhaust will likely be a larger gap to make up for the extra thermal expansion the exhaust parts get from the hot gasses.

JKing106

Look up Eric The Car Guy on YouTube. He has a video on setting Honda valve lash.


Posted from Honda-tech.com App for Android

89 SI zero

yeah, sorry. valve lash. and i have a d16a6 head

GTRay7

On some heads and valves I can chuck the valve stem into a drill and pull outward while spinning the drill. I generally use a medium grit compound from NAPA. Works great and provides a consistent finish.

Ray

24TEN

iTrader: (2)

^Did that as well.

B_Swapped93

valve lash spec can be found on the sticker under the hood. as for how to adjust do a quick youtube/google search.