building first 4g63 (torque plate Q)

[Spln_Hrd]

i have rebuilt crappy engines in school but don't have experience building a high rpm high hp engine and i am getting ready to slap a mild 4g63 together. my goal is 8.5k rpm and 400 horses once an a while at the track. i want to use second gen pistons 1g crank and 1g rods clevite bearings arp rod bolt arp head studs, and hks 272's. still deciding what i want to do for springs and retainer, i want a good spring/retainer setup for high rpm but still affordable, i would like recomendations. i also need to know how much i can hone or bore the cylinder and get by with the stock bore 2g piston. i also need a recomendation on rings and if i have to gap them myself and what the gap is if i do.

also i want to know how well other peoples engines are running that were machined without torque plates, please don't respond unless you have built an engine WITHOUT using a torque plate.

 

[vintagemuscle]

Manley springs and retainers are good for 8.5k, but if your on a budget you can just use oem and shim them and then go with some titanium retainers from manley or crower and you'll be good to 9k.
To save some money on the cams i would go with fp2x or even DKS 272's.
For the cost of the 2g pistons and machining them to fit the 1g rods your probably better off with just going with some forged pistons such as wiseco or ross.

 

[TSIfreek]

You want to use a torque plate on any kind of piston you are using. You get much better ring seal and a better performing engine. You might beable to get away with it with 2g pistons but any forged pistons a torque plate needs to be used. I would not build a motor without using one. With all that time and money going into the engine I want the machineing to be as perfect as possible.

 

[Spln_Hrd]

i have free 2g pistons, i just want to know how much honing i can do before the cylinder bore is to large.

thanks for the torque plate info, looking for someone who has built a motor without using a torque plate still, i have heard from both sides of the fence.

 

[diambo4life]

No need to hear from both sides of the fence if one side of the fence is wrong!

Get a torque plate and stop fishing for excuses not to use one. You will thank yourself later.

 

[nightspeed87]

I dont know much about your torque plate question but as far as the high rpm thing, i would go with a full crower valve train kit, and also the engine wont rev to 8.5k without ecu mods ( keydriver chip is what i have in mind) because our fuel cuts off at like 7.5k, and also consider tranny upgrade before you take the rpm that high because the trans will have a lot of trouble shifting at those speeds, and a bad shift could be damaging... ( Maybe not so much for the 2g tranny as the 1g but still ) But maybe you already know all this.

 

[92awddsm]

Crower or manley springs and titanium retainers are inexpensive and will work well at 8k+ rpm.

As far as a torqueplate is concerned, they are not required. I have built many engines without one and never had a problem. The 4g63 was not machined with a torque plate from the factory and they have held up very well also.

You cannot hone much from a cylinder and still use stock bore pistons. The amount that can safely be honed is directly dependant on amount of wear in the cylinder. Have a machine shop measure the bore and they will tell you if it can be honed or if it needs to be bored oversize.

 

[pneumo]

...looking for someone who has built a motor without using a torque plate still, I have heard from both sides of the fence.

Mitsubishi built our motor without using a torque plate, and a stock motor has proven to be capable of handling more than 400HP. Since you state that you're building a mild setup for 400hp you might not need to spend the extra cash to have your motor honed with a torque plate.

Since diambo4life seems to think I'm wrong for recomending that you skip the torque plate, I'll back it up. My previous motor was built without a torque plate and it saw roughly 425hp estimated from a 3080 pound car going through the 1/4 mile at over 122 mph. It had good compression, didn't smoke, didn't burn oil, didn't blow out the dipstick. Then one day it blew from preignition (not knock) from a bad head, which gave me the chance to tear it apart and have a good look inside. The crosshatch on the bore was still visible, plus the wear on the crosshatch was nice and even all the way around, up and down. There was no extra wear near the headstuds, and this was with ARP's torqued slightly above recomended specs.

I talked to a few machinists about torque plates and they said it's not needed unless you're going for really high HP and need every last advantage. I also got to see a block that absolutely required a torque plate- a Ford 5bolt block! The difference was that the Ford block had the headstud hole cast into the backside of the cylinder bore, so when the studs are tightened they pull on the liner.

The 4G63 has a better design, here's a pic. You can see the gap between the stud hole and the cylinder. The cylinder is isolated from headstud distortion.

 

[Defiant]

Three + decades of engine building, I've never used a torque plate. I've never lost an engine.
As other threads will tell you, there's even arguments whether you can use a steel plate on a motor with an aluminum head, and whether the block has to be filled with hot coolant, and how much the planet's crust is being distorted by the drift of the magnetic north pole.

You can get just too obsessive about details.

Meanwhile, you probably can't get equal torque on any two fasteners, regardless what the wrench or stretch gauge says.

My say is that it just doesn't matter. That's me.

If it's really a concern, engines would be built like Offenhausers, all one piece. No separate head. No head gasket, studs, bolts, locating dowels nor any of the rest of it.
One bad combustion can blow any head off the block, or fracture ring lands and worse. Whether a torque plate was used or not.

 

[T is for TURBO]

Excuse my ignorance, but what is a torque plate?

 

[steel_3d]

A torque plate is a machined block of metal that you bolt to the block when honing, to simulate the distortion caused by bolting the cylinder head down. http://bhjproducts.com.

After two blocks done with two torque plates, I sit on the "don't matter for shit" side of the fence. First block was machined with a steel plate. Cylinders checked out more or less ok, but as soon as the head was bolted on instead of the plate, they were out by a thousandth of an inch (taper/out of round). So me being a smart guy, figured an aluminum plate would have to do better. Well, this time, even torquing the plate down with the same gasket it was machined with, the cylinders are still not straight. This was a composite gasket that took a bit of a beating in the honing oil and being assembled and disassembled several time. Bought a new gasket of the same make - different readings but not better. Even the guy at the shop couldn't get it to measure the same as it did the day it was on the hone, when he says it was perfect. He machined it over two days, since it's known that letting a block sit overnight will change the shape of the cylinders. This setup is actually a bit better when the head is torqued down, there's only .0007" taper/oor in the worst cylinder, and the biggest difference in readings across cylinders is a bit less than .001". This is all way outside of factory spec.

The numbers change quite a bit with varying the torque settings, putting on different gaskets (all composite), or swapping the head for the plate or nothing torqued down. But it ain't straight no matter what.

My question to all those who say a torque plate is a must: have you measured the cylinders with the head torqued to spec? (Not to mention measuring it at operating temperature turning 8k rpm and pushing 30 punds of boost).

I don't think I'll bother next time.

Same goes for line honing. I've had line hone jobs done on two blocks, and they're both tapered, out of round, and differnt diameters. Every time you take the caps off and put em back on, the numbers change.

Maybe there's shops out there who can get it right, but I know that one very reputable dsm shop isn't one of them.

As for your ring gap question: from what I've seen, .019" top and .022" second ring gap would work for your power goals. A coupla thou looser than that wouldn't hurt anything either and it'll give you more room for growth. The deal with rings is that if you put too much heat into them, like with high boost and/or nitrous, they expand, and if they butt up they can only expand outwards and gouge the cylinder walls. Better loose than sorry. If you look around the net you might find studies showing that even 1/16" gaps have little effect on compression. Go figure... http://www.diagnosticengineers.org/Page B5-37.htm OR maybe you believe this study:
http://www.federal-mogul.com/cda/content/front/0,2194,2442_2905_8682,00.html .

 

[blue1]

I machined the guts out of an old head and used that, being that it would give me the best simulated results of have a head on. If you are running a cast head use a cast torque plate(steel), if you are running an alloy head use an alloy torque plate! we found by using the torque plate (cut up head) there was a .0002 difference in the deck approx .750 down, i really would go to the trouble unless you are really chasing big numbers of HP, for your 500 whp it really wont give you the gains for the effort. you will never notice the difference if you pick a good machinist with good equipment that knows what he is doing. Cylinder finish from the hone is more important than using a head plate, so choose you machinist wisely go by who others have used and had no issues, never over rev during intial break in always load the engine and vary the speeds.
Change the oil and filter after the first 20 mins of running in the shed and then hit the roads with a break in, keep in a higher gear so your revs don't creep to high and engine has load-5000rpm for about an hour, go home check you have no leaks, enough oil, tune is ok and then go and give the police a run for their money! then change the oil and filter !!!! Take care!!

 

[TSIfreek]

Thanks for the info on the rings STEEL 3D interesting.