valve clearance issues with kelford 272's

[chardbox03]

I recently finished a year long build on my 90 gsx. sadly after around 30 minutes of the car running PERFECTLY we had to pull the motor because of a leak coming from the oil pump. Car was still in perfect timing on the cams, crank, etc. we replaced the seal put the timing belt back on and attempted to retime the motor... when i was rotating the crank with my breaker bar the cams started binding and the belt skipped a tooth. we noticed that the valve springs were binding so when we took the cam caps and cams off and there were gouges in the CAM JOURNALS and minor scratches on exhaust cam!!!! Needless to say metal was in the pan so the bearings have to be replaced also. there was also 1 cracked valve guide and 12 bent valves... mods as follows... eagle crank, manley rods, arias pistons .20 over, dual springs, titanium retainers, kelford 272, 1mm oversized valves, c.o.p. setup w/ aem cdi, ems, 750cc's, 16g to break it in. The pistons are recessed quite a bit for valves so i dont think that i have a clearance issue.... i took the head back to the machine shop and the guy thinks that i have valve clearance issues... but he will fix the head for free??? i think hes giving me the runaround telling me i over revved the motor when it never saw over at the max 2000 rpm... the valve guides looked pretty shotty also.... what does the dsm world think??? was it a bad valve job and "baking soda" blasted head that doomed my motor???

 

[SupremeDsm]

Why do you have over sized.valves? You do know thats just a selling point correct? You should be using standard size valves. How in thebworld did you bend 12 valves with a breaker bar? Did you have the hulk on the other end. Seems like to me there is more missing to.this story.

 

[james3340]

+1 its goin to be hard to bend valves with a breaker bar

 

[chardbox03]

I have no idea...?? I'm not looking for critiques on the build... The head an block were all machined and am running a cometic mls... Has anyone experienced or heard of valve clearance issues with a similar setup??? Besides timing being wrong what could cause the valves to bend???

 

[redyute1]

Why do you have over sized.valves? You do know thats just a selling point correct? You should be using standard size valves. How in thebworld did you bend 12 valves with a breaker bar? Did you have the hulk on the other end. Seems like to me there is more missing to.this story.

Agreed

 

[nightmares GS-T]

Why do you have over sized.valves? You do know thats just a selling point correct? You should be using standard size valves. How in thebworld did you bend 12 valves with a breaker bar? Did you have the hulk on the other end. Seems like to me there is more missing to.this story.

More flow? Eventually with a big enough turbo and alot of boost the head can become a restriction. Maybe not on the OPs build but there are plenty of guys here that benefit from swapping to a built head with 1mm oversized valves. As for the OPs situation I agree bending all those valves using only a breaker bar would be pretty difficult.

 

[Spyderman7]

Timing was off when you retimed it and you still had the sprk plugs in so you probally could not tell if it was compression in the motor or bending valves while turning it over is my geuss on what happened.Next time turn it over by hand with the spark plugs out .
Also what springs/ret are you running?
Also I always run +1 over valves and do some bowl work on all my heads and you will see better gains in top end over the standard valves any day.I dont know +1 valves are just a selling point

I missed this but To crack a valve guide might be hard to do turnig it over by hand .

 

[BogusSVO]

For one you have the wrong valve springs, you may have hit spring bind. If you read what Kelford says about there cams, they Recomend Beehive springs, I know of 3 Beehives on the market that will handle the Kelford Cams, The ones Kelford sells, the Kiggly Springas, and Ferrea Beehives.

http://www.dsmtuners.com/forums/newbie-forum/341209-4g63t-valve-spring-info.html

No issues with the +1mm OS valves, if they were installed properly, and with the correct Valve tip height.

Now for the scratches/gouges in the cams and caps..
For the caps, did you prime the engine oil system before fireup? Also from forcing the cams over spring bind, caused the cams to "flex" and remove the oil clearance from the cam journals.
The marks on the cam lobes is also from forcing the cams over the spring bind.

The bent valves will be from valve to piston contact. Did you check (clay the valve releifs) during assembly? As a ruel of thumb, you should have .040 clearance on the intake and .060 on the exhaust.

It sounds like you had the timing right at first, but it got flubbed when you reset it after fixing the oil leak.

As far as the machine shop "fixing the head for free" I do not see a reason they should
How is the machine shop responsiable for cracked valve guides and bent valves?

How do the Valve guides look "shoddy"?

http://www.dsmtuners.com/forums/newbie-forum/341218-how-change-valve-guides-4g63t-head.html

The only way "baking soda" blasting your head head "doomed" your engine is if they oil galley plugs were left in and there was blasting media was left there that the oil picked up and washed thu the engine.

Post pics of the cam caps and cams.

 

[1fastlaser]

Can someone share light on to what tip height we should be shooting for?

 

[chardbox03]

I've researched many tuners builds and I've never heard of anyone having problems with the same setup... Anyways i ended up getting another head and new valves, guides, cleaned everything and am about to take the new head and block to be revamped again. I probably should of used a degree wheel in the first place...

ohh yeah spyderman7 im running si dual springs, manley retainers

 

[NHerron]

I can give you tips and info on degreeing our 4g63's if you have any questions, I just got through doing it. Hit me up anytime.

 

[chardbox03]

thanks supremedsm, i found a nice write up on the forums on how to properly degree.. I also just picked up a nice magnetic base dial indicator also!!! Ill keep you guys posted... hopefully she should be running within a few months again!!!