hi everyone, this is actually littlemiss300's better half. Unfortunately not long after the motor swap (before me) her stock vg30de has dropped atleast one valve and lost a substantial amount of compression in 2 cylinders. so its time for me to rebuild the heads. with out sounding arrogant im very handy with motors but im a toyota man (please dont hate me) and have no experience with these at all. so i have a few questions that hopefully you guys can help me with. 1. is it possible / worth it to pull the heads off with the motor still bolted in or should i just pull the sucker out. i also intend on giving it a new full timing kit and water pump ( kinda silly not to) 2. is there and great company that you can reccomend for parts that specialize in Z's such as i intend on putting in thinner MLS HG's along with of coarse new stem seals and what not 3. Any good tips or advice including things to look for and lil performance tricks? This is not my 1st motor build and like to pay attention to detail from porting and port matching the heads to checking valve clearnaces Any help in these areas will be monumentally appreciated. thanks Rob
Some answers from other posts I have read over the years 1. Heads can be pulled off in the Car. But many just take out the whole motor. It doesn't take long to take it out 2. mentioned many many times if you run a search. Places for parts are Concept Z performance. Z1. Caz racing. these are the best places, if there are others I don't care for them as these 3 have always had what I needed 3. I don't know about performance mods to the heads. I guess there could be some cheap horsepowers to be had if you are handy with a die grinder and know what you're doing. I don't in that regard though, so can't really help there. Don't worry bout valve clearances either. Hydraulic lifters will take care of that for you
ok sweet thanks. i figured i was best off pulling the whole motor yer im pritty handy with a die grinder, ported the head on my motor and made a massive difference. another question. whats the interchangeabillity like between the N/A and TT parts in terms of head studs and HG's? and also anyone know the stock N/A HG's thickness?
Head studs HG Looking at all the head stud kits for sale, list both N/A and TT. So From that I would say they are not the same. the head gaskets will be the same to look at, but different thicknesses. High comp N/A and Lower TT. Why do you want to have interchangeable parts?
was wanting to make sure. some parts i was looking at specified, some didnt. im used to working on 3sge and 3sgte motors mainly and most performance parts are only listed as gte but are interchangeable with ge such as gaskets and head studs etc
What makes you think the engine has dropped a valve? If that is the case then you will have more than just the heads to repair. Most likely a broken piston and/or damaged bore. Does the engine turn over / run without making any unusual noises? If so, then most likely you have just done a head gasket. As for head work, have them hot tanked and crack tested first then do your porting. Once ported get them checked for true and/or lightly surfaced. If the valve stems are ok i'd consider having phospher bronze inserts fitted. You'll have to have the valve seats faced and valves cut and synchro-seated. Have the valve springs tested once assemble for seat pressure. I'd put a set of pipes on it and make sure the airbox can breath well, maybe a pod filter if there's still some cash left in the budget. A little head work, pipes & exhaust, airbox mods and a tune should give you 10 - 20Kw @ the wheels. Good luck. Regards Ivan
it was taken to donteks where it was diagnosed. the car runs fine just loss of power. Oil is clean (no sludge) and not loosing any water. and only time it gets smoke is when foots planted but thats pure oil lol and only out of the 1 side with the dropped valve the head is most definately being sent away for a skim and examining before i rebuild it. no question there I can get the valves cut and re-seeted for free. i of coarse am hoping i can get away with just lapping them in. you are right though in that it could be more then just the heads being sad but if theres problems with pirtons or in the bores the heads are going to have to come off anyway
Head bolts/studs are the same between NA and TT. Head gaskets are the same between NA and TT. Pull the motor and don't stuff around. Comes out in a few hours and working the engine on the stand will save your back. Don't bother with a MLS gasket on a NA. No point and you will have to deck the block to get the thing to seal.
thanks thats exactly what i needed to know. Im still not 100% sure on how far to go with the rebuild. depends on her funds lol
Depends what's wrong with the thing. Anything much more than a blown head gasket and it's cheaper and easier to just buy a good running NA VG. Can be had for ~$500 if you look hard enough.
yer thats what this motor was. blew the HG before i met her. bought a 2nd handy and had that swapped in now this has happened. for the added piece of mind id rather just rebuild it. if another motor was bought id wanna open it up to inspect anyway
