ILIA Posted January 10, 2010 Share Posted January 10, 2010 I'm at the point where a full rebuild is mandatory. My question is with all the options what do I get? I've heard that "get exactly what you had" in the first place, but I don't know what I have! Do these rigs come stock with R.V. cams? If not, would it hurt? Could an R.V. cam increase the risk of blowing a head gasket? Guessing a rebuild with a new head would be ideal. Any other advice will be much appreciated. Thanks Quote Link to comment Share on other sites More sharing options...
Maineah Posted January 10, 2010 Share Posted January 10, 2010 Unless your engine is trashed (connecting rod through the side) there is no reason it can't be rebuilt to new condition cylinder head and all. I would say you are just as well off with your stock cam as any thing you can buy. Just replacing the cam with out springs etc. is not a good ideal and the gains are really are not worth the expense. All of the Toyota engines were of one build, factory so a 22RE no matter what it was in is the same. Any thing else some one installed after is was built. Quote Link to comment Share on other sites More sharing options...
ILIA Posted January 13, 2010 Author Share Posted January 13, 2010 Well lets say for example the pistons, rings, and block are fine. Would a new head with an RV cam lower my MPG? What are the pros and cons with this cam on a motorhome? Quote Link to comment Share on other sites More sharing options...
Maineah Posted January 13, 2010 Share Posted January 13, 2010 Well lets say for example the pistons, rings, and block are fine. Would a new head with an RV cam lower my MPG? What are the pros and cons with this cam on a motorhome? Is your head bad? I would think you would take a hit on MPG with a aftermarket cam how much? good question. The stock cam is a pretty good blend of torque and power and I don't think you would notice much difference trying to move a 6,000# pound motor home with a different cam as you might in a 3,000# pickup. Quote Link to comment Share on other sites More sharing options...
WME Posted January 14, 2010 Share Posted January 14, 2010 Rebuild vs overhaul. Rebuild.... new head, cam and valves, new OS pistons and rings, new rod and main bearings. The block needs to be bored over sized for the new piston. Overhauled.. Have the head checked for straightness, have the valves ground. With the OHC set up is very iffy to plane the head to make it straight. You would have to hone the block and install new stock sized rings, new rod and main bearings. Its sorta of a pain but with a friend you can do a hillbilly overhaul on your engine with the block in the truck. New rings and rod bearings only can't change the main bearings. If you take the block out then you can do mains too. Either way rebuild or overhaul you will need a new water pump, oil pump and a timing chain set. FWIW I've done the hillbilly in the truck overhaul on 2 engines and it work out just fine, Ive also rebuilt engines that turned out fine, IF you can find a good machine shop to do the block correctly. Sloppy machine work when you are rebuilding is much worse than doing a hillbilly overhaul Quote Link to comment Share on other sites More sharing options...
doktasoohs Posted January 14, 2010 Share Posted January 14, 2010 wtf is an rv cam omg roflmao Quote Link to comment Share on other sites More sharing options...
longwater Posted January 14, 2010 Share Posted January 14, 2010 I guess the question is are you capable of doing the rebuild yourself.You will need machine work on the block,and head.If you have the ability ,you can save some money and pick quality parts,although no warranty. You could take it to a shop and have it rebuilt,if you know the shop,you may feel more secure but this may be the most expensive route,you will probably get some kind of warranty.The other option would be to buy a rebuilt long block,( or short block if your head has been rebuilt or replaced ) There are a lot of auto parts stores that offer rebuilt engines.Most will offer a 3 year warranty,still someone will have to remove and replace the engine. This is the route that I would take,when I was younger I would have rebuilt it myself,but now I like the warranty.As far as getting a better cam I think there has been alot of discussion on this forum and most say stick with the stock cam. LW Quote Link to comment Share on other sites More sharing options...
Maineah Posted January 14, 2010 Share Posted January 14, 2010 If you are an amateur a do it your self rebuild is not a good ideal you will need precision measuring tools, accurate torque wrench and a damn good ideal of how all of it fits together. If you feel confident about reassembling an engine then you could do so after a visit to a machine shop. There is a lot that goes into a proper rebuild degreasing, boring, regrinding the crank, valve guides, valve grinding and by the way a good 3 angle valve job would be a better improvement then a reground cam. I did look at a power/torque graph from a couple of “RV” cam outfits and the only thing I saw was an improvement in torque at about 3,800 RPM not much horse power gain and the higher end torque came at the expense of lower end torque with a stock cam. Quote Link to comment Share on other sites More sharing options...
ILIA Posted January 14, 2010 Author Share Posted January 14, 2010 I'm gonna purchase a professionally rebuilt motor with new head and warranty. Seems for me like the best route to go and fewer headaches. They are pre-run and come with a print out of compression and oil pressure. At this point I'm just curious if the RV cam will allow me to use the overdrive a bit more often to save MPG? Or in 3rd on my automatic will it suck more gas? Anyone running something besides the stock cam? Quote Link to comment Share on other sites More sharing options...
Maineah Posted January 15, 2010 Share Posted January 15, 2010 I'm gonna purchase a professionally rebuilt motor with new head and warranty. Seems for me like the best route to go and fewer headaches. They are pre-run and come with a print out of compression and oil pressure. At this point I'm just curious if the RV cam will allow me to use the overdrive a bit more often to save MPG? Or in 3rd on my automatic will it suck more gas? Anyone running something besides the stock cam? Good plan that by far is your best way to go. I know I'll hear about it but I run mine in O/D all the time (so maybe I'll only get 120k instead of 150k out of it) and it's bone stock. You may ask about your warranty if you change the cam. Quote Link to comment Share on other sites More sharing options...
Tom W Posted January 15, 2010 Share Posted January 15, 2010 Torque if it comes in at a higher rpm then OD wouldn't be to good, I would rather have lower gearing ( rear end ) or a higher number instead of 4.10 maybe a 5 something to 1, Just my thoughts more torque out of these wishful thinking. Maybe the eng is not that bad on dissemble and some measuring who knows with heads off is there a ridge to speak of?. I check all machine work after its done there have been mistakes, last one had rebuilt heads on when I discovered they pulled the threads on several of the cam towers they paid for the helei coils. Quote Link to comment Share on other sites More sharing options...
WME Posted January 16, 2010 Share Posted January 16, 2010 Changing the rear axle ratio is like add a bunch of hp. A 4:56 with a stick and a 4:88 with an auto. Change the rear axle and add a cam that's about it. The next power increase would be a bigger engine transplant. The O/D ratio is just to much for a heavy RV. Your cruse rpm should be between the torque peak and the hp peak. Now as geared your at the torque peak. OLD hot rod saying torque is how fast you accelerate and hp is how fast you go Quote Link to comment Share on other sites More sharing options...
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