Originally Posted by
Z34Phoenix
I have never seen a conversion kit to replace the belt. and im not sure it is a good idea. this engnie already has alot of rotating mass because its an over head 4 cam. if you add in a chain vs the belt it already has and replace the tensioner system, and pullies it will add even more weight to the system! and a chain long enough to replace the Tbelt would have soo much slack and be prone to breakage. and if you try seprate chains you are adding even more weight! When replacing the belt you replace all the idler pullies and the tensioner with the belt. if you do this correctly it will last another 75-100k miles! my last timing belt job lasted from 98,000 miles until the dummy chain jumped a tooth and the belt and pullies were still good at 224,000 miles! after 75,000 you check the belt every 3k to look for signs of wear and tension. the timing belt isnt as bad as people make it out to be. yes it is the main failure for the engine just because most dont replace or watch it like they should.
to be honest, i have heard people come and go talking about doing radical builds like you and never completing them. what is said about moding the 3800 holds true for this engine as well. Set a Budget and a Goal. then make a plan. considering some of the ideas you mentioned will require extensive fabrication and rarely ever done on an engine that is even more rare.... I have been in the DOHC community for 10+ year and there have only been 3-4 people who have tried making cams for this engine no specs were ever passed on nor were any results. all who tried ended up switching engines. this should tell you something.
just like the 3800 says too... i wouldnt recommend tearing down and rebuilding the bottom end. its best to find a low miles block. to properly build a bottom end, you need to have a shop hone the bore, balance everything and even still people have engines that die when all this is done. also the DOHC never looses pistons or throws a rod or spins a bearing. the only one i heard of with bottom end failure was ez112 who rebuilt his engine and it lost a piston at the track. this engine is popular in the fiero crowd and many have run turbos and put 325-350 whp.... there is one member of another forum who has a 95 Z34 who also was runing a turbo and put down 325 hp on 7 psi i believe. so i honestly think the DOHC has a stronger bottom end then the 3800 series engines.
I dont want to discourage you, but im just tired of hearing people dream up these plans and never follow thru. it just adds to the notion that this is a bad engine when it really isnt. what ever help i can give let me know. my best recommendation would be put the engine in don not go any deeper then the lower intake manifold and timing belt. and enjoy the engine. the cost of what you are saying/planing would be not practical at all. even doing the work your self you are way up there...
at least 2-3,000 for the bottome end to be replaced with forged parts and properly installed and balanced.
4 custom cams and hoping to get the specs right on the first try 1,200-1,500
procharger 2,000 once done if lucky
300+ in valves
??? making headers
???? tuning who knows ... deff hard if your not OBD2 or stand alone system.
???? finding a getrag in good shape and installing it.
that is about 6,800+ all the unknown ???? + any stumbling blocks! this could easily be $10,000+ into the engine! (not talking about labor, suspension, brake upgrades or paint).... resting on a getrag that wasnt designed for more then 200hp to begin with!
If i was told to tke 10,000 to build a 1st gen Wbody, and the restriction was not to use a 3800 engine... i would say go with the 3400 and go turbo. it might be possible to use a getrag with it or upgrade to a 4t65e and have it built for the power. and it prob will come in under budget. heck you might be able to squeeze an LS4 V8 in there! and not do anything to the engine.
