So down the road I am thinking I want to go with a 76mm turbo on my Cobra. I am looking to get rwhp into the 700s on 92 pump (is this even possible?). Anyways onto my main questions, I am going to rebuild the motor myself, I have rebuilt a Toyota 22RE (inline 4cyl) and that wasn't too bad since I had my mechanic lend me his shop and expertise. When I rebuilt my Toyota engine, I had the block and head sent off to Jerry's Auto Supply to have them machined in their shop. Should I be ok with sending my block off to Jerrys to be machined if I am going to be running this engine with such high power levels? And do I need to send the heads with the block? It would save me a bunch of time not having to disassemble the heads, but if it is required, then I have no problem doing it. Let me know what y'all think, thanks.
Engine Rebuild Questions
- Thread starter alicecooper
- Start date
More like around 600 on straight 92. If you use meth injection, you could hit your power goal.
Do a leak down test so you know what your heads are doing. If they test out, no need to send them out. Machine shop should have the pistons you will use to measure before any bore work.
I have seen guys bore without a bore and honing plate with good results, but I personally used them for my build. If your machinist doesn't have, you can rent or buy from MMR.
http://www.modularmotorsportsracing...in_page=product_info&cPath=52&products_id=781
If you think you may bump the HP later, install .200 tool steel wrist pins. .120 would probably be fine if staying around 700 HP.
Good luck!
Do a leak down test so you know what your heads are doing. If they test out, no need to send them out. Machine shop should have the pistons you will use to measure before any bore work.
I have seen guys bore without a bore and honing plate with good results, but I personally used them for my build. If your machinist doesn't have, you can rent or buy from MMR.
http://www.modularmotorsportsracing...in_page=product_info&cPath=52&products_id=781
If you think you may bump the HP later, install .200 tool steel wrist pins. .120 would probably be fine if staying around 700 HP.
Good luck!
Only 600? Well I guess that is enough for now lol. Ok thanks for all the information. I was planning on going with Diamond -19cc pistons if that makes a difference, was thinking it would keep compression around stock. And I would hope to bump the HP later as I have a 110 pump in town, or if E85 comes to town that would be nice as well.
You can easily hit 700 on 93 pump with a single turbo and do it safely..
And why do you need to rebuild your oem longblock OP? what's wrong with it?
And why do you need to rebuild your oem longblock OP? what's wrong with it?
The only reward for leaning to hard on pump gas is another rebuilt engine
Yeah i have a conservative tune on it now. I would do the same in the future. I dont like pushing the limits because my wallet can only take so much haha. I just like pump tunes because its the only thing readily available. The 110 pump is pricey.. and no E85.. like i said though i plan to mix the 110 and 92 on more aggressive tunes
.So far, nothing lol. Just hit 65k miles and runs hard every time. But i want the car to last, i dont want to risk hurting the block by burning a piston. I would rather go Diamonds to start, then power later. I know the stock pistons can handle higher power levels but the clearance kind of bothers me and the fact that i have read that reliable power on the stock pistons is in the 500 range. I have heard them taking more but for how long. If people have ran 700+ reliably on the stock motor then ill take the plunge. I was also planning on ARP everything and new timing chain kit (bad experience in the past with interference motor) lol.
You really don't do any of the noobs any favors by putting that out there. If you have perfect 93 with a really good tuner and push right to the edge, you can make 700 and not blow. But then Fall arrives and/or the 93 isn't so great and maybe the tuner wasn't so great either and we get the same rash of guys posting up about how they burned it down.
It's one thing to make the dyno run, it's another thing for that motor and tune to go stay alive in the real world.
The only reward for leaning to hard on pump gas is another rebuilt engine
I would definitely run a safe tune on pump. Like i am now i am probably giving up 40rwhp to be on the safe side. I am looking into options for E85 though. Seems like its either pay through the nose for delivery or i get to drive 2 hours and fill some drums..
So you think he needs to do a full engine rebuild to add a single turbo to his perfect running 65K miles oem longblock?
I don't see why people wouldn't run some basic safety measures when their cars are pushed that hard. A J&S Vampire anti-knock box will keep your motor completely safe even if you pumped 91 or 89 by mistake. Lack of octane would try and knock and the J&S would pull timing saving from any issues.
I myself ran 27.5 PSI and 24 degrees timing with w/m injection on 91 for a few years. J&S anti-knock box and a Lean Protection Module and saved me from blowing it up a few times.
Just my thoughts if you're going to build something high performance.
OP - I see no reason to rebuild your motor for 700 whp unless you plan on making back to back long hard pulls. Then your pistons will swell and scuff the cylinder walls as factory piston to wall clearance is on the tighter side. I've done it personally. After market pistons with more piston to wall clearance will let you beat on it all day long and make as many 0 to 160 back to back pulls you like.
If you do rebuild not sure I can recommend -19 cc dished pistons. I did that myself back in 09 and it sucked. CR is to low, throttle response sucks and gas mileage drops. These cars already are so short ranged between fill ups because of a small tank and thirsty engine, the problem gets worse. HP will be down a bit too because it's not as efficient as it was with stock CR.
I was thinking -19cc because it would be close to stock after the block is shaved, but if that is too low I will go with -15's then. But with what I am hearing in this thread, I might just go turbo first. I have the head cooling mod, I would get a better radiator, a better t-stat and monitor my IAT's,engine temps, AFR, etc... I don't plan on making any runs past 4th and I don't really plan on back to back runs. I am pretty easy on my car to be honest. I would like to be able to go into boost over and over again, but if/when I do that probably wouldn't ever get past 5k. Just to give you guys an idea of my driving style. I don't like to beat on my cars lol. I am guessing from what I've read the BB 76mm should spool around 3.8k. That sound about right?
Why would you block be shaved so much? Also be aware shaving the block or the heads a significant amount will change cam timing. Then you're into adjustable cam gears to correct that. Although one could argue you should degree your cams anyways because of factory tolerances but that just depends how far you want to get into it.
Factory radiator is more than fine. In fact it's great. I had a Mishimoto for a while when my factory sprung a leak and didn't like it at all. Car ran noticeably hotter. There are various air ducting mods you can do to try and force the air through the thicker radiator but I was already sick of it because it was far from a bolt in solution. Found another factory replacement and back in business.
I'll let the guys with more turbo experience on the 4.6 chime in on turbo sizing.
Op if it ain't broke, don't fix it.
Doesn't sound like you push it that hard so why add headaches and expense right now?
If you really want to go turbo I'd say do that now with the required mods, get the bugs worked out, and enjoy it. On 92 and a turbo I think low to mid 600s is safe.
Doesn't sound like you push it that hard so why add headaches and expense right now?
If you really want to go turbo I'd say do that now with the required mods, get the bugs worked out, and enjoy it. On 92 and a turbo I think low to mid 600s is safe.
Heh, I use that saying all the time. I just like the peace of mind, but from the responses I am getting, I am feeling pretty safe with pushing the stock rotating assembly. Thanks for the feed back, I am still looking into E85 options, hate how I don't have any pumps in town
and the 110 is leaded...Yeah i have a conservative tune on it now. I would do the same in the future. I dont like pushing the limits because my wallet can only take so much haha. I just like pump tunes because its the only thing readily available. The 110 pump is pricey.. and no E85.. like i said though i plan to mix the 110 and 92 on more aggressive tunes
So far, nothing lol. Just hit 65k miles and runs hard every time. But i want the car to last, i dont want to risk hurting the block by burning a piston. I would rather go Diamonds to start, then power later. I know the stock pistons can handle higher power levels but the clearance kind of bothers me and the fact that i have read that reliable power on the stock pistons is in the 500 range. I have heard them taking more but for how long. If people have ran 700+ reliably on the stock motor then ill take the plunge. I was also planning on ARP everything and new timing chain kit (bad experience in the past with interference motor) lol.
Not sure where you got your misinformation on the stock pistons only being good for the 500hp range, but that is not true at all. Not even close. Many people are running 6-700+ on a stock longblock(with fuel and FI upgrades). and I would say most are at least in the 500hp range on this site. Its all in the tune and the driver. When I used to hang with the terminator crowd(been spending a lot of time on bikes lately), I would be the slow one in the upper 500 range.
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