'99 ohv 4.0 cam build

[QueenCitySleeper]

well I just spent 12 hours of my weekend porting and polishing my new cylinder heads just to find a crack in one of them on the exhaust port where the manifold bolts up. Guess Ill be ordering another

 

[jd4242]

well I just spent 12 hours of my weekend porting and polishing my new cylinder heads just to find a crack in one of them on the exhaust port where the manifold bolts up. Guess Ill be ordering another

What heads did you go with? And wow 12 hours is ALOT of time to be p+p.be carful you can over do it and hurt the flow.they shouldnt need that much work.where is this crack?post a pic.you should all ways have any head tested before and after any work is done,especially after port work.

 

[QueenCitySleeper]

cracks are on both sides. the left one is easy to see, the right is slightly smaller. Both extend about 1/4 into the flange

 

[QueenCitySleeper]

oops here's the correct one. Again cracks on both sides

 

[QueenCitySleeper]

These were advertised as 95-97 heads. They are the ones you suggested I buy, but they look a lot like the 98tm

 

[jd4242]

Eww wow.yea thats really odd.they would have taken them back if you didnt port them.they will look just like 98tm but they exhaust ports.i can tell you your way over doing it if your porting them for 12hours.only thing that really needs to be done is gasket match the exhaust,smooth out the sharp 90* in the exhaust port and polished up.otherwise your wasting your time and hurting flow.they are all ready designed to flow better and if you dont have a flow bench then you cant tell when your over doing it.

 

[QueenCitySleeper]

I cant find another head around $104. Ill check around for machine shops that can fix it tomorrow. If cast iron was easy to weld, I'd do it, but its obviously not. I understand that there are several ways to fix cracked cast iron heads, but these cracks are in a tricky spot, so we shall see.

 

[Dono]

Wow, I can't believe that heads cracked. That really is bad news. Im looking forward to finding out if it can be fixed at a reasonable cost.

Ready to sell your Borla muffler to me? Sorry, I couldn't resist.

 

[QueenCitySleeper]

Well I contacted Enginequest and sent several pictures showing how the cracks are due to casting flaws. They are sending me a new head no charge.

Dono, I will NEVER part with my Borla!!

 

[jd4242]

Well I contacted Enginequest and sent several pictures showing how the cracks are due to casting flaws. They are sending me a new head no charge.

Dono, I will NEVER part with my Borla!!

they are a great company for sure.did you tell them you ported it?do they want the old one back?

 

[Dono]

I can hardly wait to hear your motor. I have Borla envy. I just might have to get one.
I loved the way my 4runner sounded.

Thats awesome that you have a new head on the way.

 

[QueenCitySleeper]

yes I told them I had ported it and didn't find the crack until I had it all cleaned up. They were hesitant at first, but after I sent them several convincing pictures of casting flaws it cleared up any doubt. I was sent a shipping label to return the bad head.

Do you or anyone else have measurements on how far the spring seats need to be cut to fit the 988 dual valve springs?

 

[jd4242]

yes I told them I had ported it and didn't find the crack until I had it all cleaned up. They were hesitant at first, but after I sent them several convincing pictures of casting flaws it cleared up any doubt. I was sent a shipping label to return the bad head.

Do you or anyone else have measurements on how far the spring seats need to be cut to fit the 988 dual valve springs?

That takes a special tool to do it,would not suggest you try that at all

 

[QueenCitySleeper]

just got the new head in today. Ive got all the accessories off the motor and am about halfway into getting the intake manifold off. Things are going smoothly so far. Any tips on removing the timing cover and intake manifold?

 

[Dono]

Its pretty straight forward, as you probably already know.

 

[QueenCitySleeper]

Ive got everything off but this egr pipe is giving me fits. I want to delete the egr system all together and tap and plug the ports. Will a Henson tune take care of an egr delete?

 

[jd4242]

Ive got everything off but this egr pipe is giving me fits. I want to delete the egr system all together and tap and plug the ports. Will a Henson tune take care of an egr delete?

yep

 

[QueenCitySleeper]

ok great. I dont like the idea of putting hot exhaust gases into my intake air anyway. I may have to cut it get it off, then clean things up once everything is out. I dont see how it can be removed from the intake manifold and the steering shaft is right in the way of fitting a wrench on the manifold side of it.

 

[Dono]

I hear you on the hot gas thing, but...
There has been many discussions about the egr. End result is that its a good thing. It actually helps cool combustion due to the chemistry of the whole thing.

Egr does not function at idle, or wot. It does help keep your burn cool. How much does it help under part throttle conditions? Probably very little.

The other side is that the egr line is a pain in the a$$ and that in its self can be a good enough reason to get rid of it.

Right or wrong, I have retained mine. If it was just for emissions, I wouldn't have bothered with it. Is it helping? No clue, but id like to think so.

 

[QueenCitySleeper]

The lower intake manifold is out. I decided to stay with the egr. Went to take the timing cover off and realized it wraps around the crank. So until I get a crank puller Ill focus on getting the heads off and assembling the new ones