I'm having to ask this because I know dropping a valve is a...common?...Issue with the B series and it means the end of the motor. Just curious here but running GSR cams with GSR valvetrain, however unknown mileage. Is there a higher risk here and/or is it a stupid idea to buy a P72 head and just throw it on? If it matters the casting date is 1993.

 

Just rebuild the head with the components of your choosing and call it a day!

 

Problem is I'd like to put it all together now with the GSR stuff and when the GSC cams finally come back in stock upgrade to them. Other option is to just wait on the GSC T1 cams to come back in stock to put it all together. GSC has no ETA on when they will produce more and I've called every shop I can find that sells them with no luck.

 

Isn’t the 1993 GSR the B17 engine, and in 1994 they changed it to the B18C1? The B17 is still a good engine, I think it’s more like a stroked B16.
As far as using it with unknown mileage I’d say go for it, then wait for the new parts to arrive later on, and install them when you get them.

 

This is how companies intensify demand for their items!
At any rate, build the head and run the stock cams.. When you get whatever set you're after, drop em in.. If you're building to support the GSC cams anyways, sounds like the rebuild was in your cards all along. Lol!

 

ETA is Fall of 2021. Most dealers only get 3-5 sets at a time because demand fluxuates so much.

 

It doesn't matter that much, but a 1993 casting does tell me that the Hydraulic LMAs might be wearing out. (I had that happen with project Ghost that started off with a 1993 GS-R head.) But that really depends upon how this head was treated prior to your receiving it. If it looks like the oil was changed regularly and didn't turn into sludge, contaminating components, then you should still be good.

 

I will post pictures tonight. With that being said I read the importance of running hydraulic ones with the GSC cams. If the factory LMAs are bad is there a way to rebuild them or repair to serviceable?

 

Skunk2 makes a good replacement set.

 

Skunk2 does not make hydraulic LMAs

 

From what I've seen, dropping a valve is typically the result of improper assembly or valve float at crazy high RPM.

So as long as it's not reassembled by a monkey and you're not revving to the moon (which I doubt you are on GSR cams) then you're good. I think replacing the LMAs is a good idea as mentioned.

 

Pictures of the cylinder head, opinions? I honestly don't know how to check the LMAs but I did press down a little on the middle big flappy thing and it went down and popped back up quickly. Anyways, pics...

And no I wouldn't want to rev it to the moon, 7,500-8,000rpms until getting the GSC cams and then a max of 8,500rpms assuming the turbo takes power that far.

 

And your GS-R head does not use HLAs.

 

grooves in rocker arm pads scare me, mine were worse. I suppose the new cam lobes will match up ew on pads?
I think your big flappy thing looks great no homo, but the primary rocker pad is reasonably worn. mine was only half a thou deep so maybe I'm just trippin

 

I guess then there is also the question of, how do I know what valve springs I actually have in the head? Any pointers on how to identify?

 

Virtually none. The "safe" assumption is that you have a visibly unmolested GSR head and therefore have stock components. Very few instances, you may still see some of the factory paint marker buuuut.. Don't hold your breath. The CTR and ITR use dual intake and exhaust springs, the GSR and B16 use dual intake/single exhaust.

 

If it was me I would do everything based around the cam you decide to use and just wait. I would replace the valves, valve springs, retainers, locks, guides, seals and you don't have to port and polish if your power goals are relatively low.

I've scattered two motors because of valves and after that I've never used anything but Ferrea. The last motor that shot a rod out at 11,000 RPMS, the piston slammed the head and barely bent the valve it came in contact with. When you use really good quality components you don't have to really question the strength and integrity. Don't get me wrong crap can and does happen but it is worth the extra coin to get quality ****.

 

I agree with the above. ^

However if you're set on using the head in stock form for awhile, it appears to be in good shape. It was definitely well maintained with quality oil judging by the color of the metal. Give each retainer a light smack with a socket and a hammer. If nothing comes flying out, send it. Just don't rev it to a billion.

 

I agree. By the time it’s verified that it can work in the condition it’s in and installed, the time and money are better spent upgrading all of the valvetrain now. For the entire valvetrain it should be about $800 plus labor.
It could work now, but it’s more efficient to do the valvetrain now rather risk having a valve stem seal leak, or a valve float at 8000 RPM because the springs are 28 years old from a ‘93. Then just drop in the cams when the arrive.

 

yeah, they actually do.

 

So, this one pictured in question uses hydraulic lash adjusters? Please point this one out to me as I am still learning the B platform and don't need to **** **** up..

 

Look under the center rocker.

 

The LMA?

 

Yes - pretty sure that's what TheShodan is talking about.

 

Hydraulic lash adjusters. Not the same thing as the lost motion assembly.