Rebuild questions

[JuGs]

Ok Im thinking of rebuilding my motor this winter. I might go with just a stock rebuild but was wondering if I needed upgrades what ones I should get? Im running a holset WH1C and have goals of 400 to 500 to the wheels. I know the stock block can handle this HP range but my main concern is the head. can i leave that stock as well or what upgrades should be done to it in order to run 25 to 30lbs of boost? Will upgrading the cams and springs be fine?

Also if i deside to stay with a stock build with the holset whats the max psi i should run with a stock build? Ill be changin my injectors and clutch at the time of build to 1050cc. I can safly run 25lbs with a compltly stock block and head right? I should be able to. My buddy was running 34 on a stock built block with a 50 trim.

I would be more than happy just to hit 400 to the wheels for now and feel a stock build is more than enough just looking for more input before i start

 

[gabytech]

Ok Im thinking of rebuilding my motor this winter. I might go with just a stock rebuild but was wondering if I needed upgrades what ones I should get? Im running a holset WH1C and have goals of 400 to 500 to the wheels. I know the stock block can handle this HP range but my main concern is the head. can i leave that stock as well or what upgrades should be done to it in order to run 25 to 30lbs of boost? Will upgrading the cams and springs be fine?

Also if i deside to stay with a stock build with the holset whats the max psi i should run with a stock build? Ill be changin my injectors and clutch at the time of build to 1050cc. I can safly run 25lbs with a compltly stock block and head right? I should be able to. My buddy was running 34 on a stock built block with a 50 trim.

I would be more than happy just to hit 400 to the wheels for now and feel a stock build is more than enough just looking for more input before i start

If you rebuilding the engine and looking for 400-500 whp, you should forged the bottom end. If you looking to rebuild the engine, you might as well forged it now and get it out of the way. There's no doubt the stock block can handle the power, its more like how long can the block handle it for.

 

[JuGs]

If you rebuilding the engine and looking for 400-500 whp, you should forged the bottom end. If you looking to rebuild the engine, you might as well forged it now and get it out of the way. There's no doubt the stock block can handle the power, its more like how long can the block handle it for.

that had crossed my mind but funds and time will be a huge play in this build. Ill have to be working around my other project im working on for a friend. But If i were to forge the bottom I was going to buy parts one by one and wait till I get everything I needed and then pull motor and start. If i did it that way it woulndt be till almost end of winter before i get to start tearing it down.

What valves and springs would be best if i went with 272 cams?

 

[4G63_GSX]

I have ferrea beehive springs and ferrea comp plus 1mm oversized valves

 

[H@xtGSX]

A cheaper option I used that has been worth the effort valve wise was using an Evo spring set, and hand lapping each valve to the seat with ultra-fine lapping compound. The lowest compression piston I had after doing that was reading 176 psi. There are heavier spring sets you could use, but as long as the valves are mated really tight to the seats by lapping them in, they shouldn't have any trouble staying shut. As for how much abuse the Evo set can handle from steeper cams, I don't know. The steepest cam I have used is a 264, but I had no issues with it, even on the stock springs.

 

[JacksonAuto]

Evo springs aren't an upgrade. They're ok if you want something a bit lighter, but if you'll be turning higher-than-stock RPM or boost then they'll be a downgrade.

If you're on a budget you could do a nice, balanced and blueprinted stock rebuild with NPR or TopLine pistons, ARP rod bolts, etc which will strengthen the bottom end well enough to handle 350-400WHP reliably. Combine that with a nice valve job on the head, new springs and seals plus mill it an you will have a nice engine that will run for a long time. Figure around $1200 in the bottom end and another $400-600 into the head assuming that the guides aren't worn or the seats aren't pitted up too badly.

If you've got some extra cash to spend or want to make more power, consider a forged setup with Eagle or Manley rods and Wiseco pistons. Something like that will handle 600 at the wheels and hold up for years. For the head, worthwhile upgrades would be stainless valves with kiggley springs and some slightly larger cams along with a competition valve job and minor portwork. Figure around $1800-2200 on the shortblock and around $800 on the cylinder head for this kind of setup.

 

[BogusSVO]

^^^ X2

The Kiggley springs are a nice upgrade, but use a thick seat locator, I like The GSC 5041 kit for the taller sping used.

Either set will work fine with the more agressive 272 cams, kelford, GS3(?) and the Big FP cams

If you go with smaller 272 cams like the HKS, Comp or BC, then a set of BC1100 or manley singles will be fine and save a couple hunders dollars.

http://www.dsmtuners.com/forums/newbie-forum/341209-4g63t-valve-spring-info.html

http://www.dsmtuners.com/forums/cyl...omparison-stock-hks-bc1100.html#post152945194

http://www.dsmtuners.com/forums/cyl...2-evo-viii-stock-dsm-manley-brian-crower.html

Also if you do keep the stock valves, make sure they have 6T on the valve head, no there are some stock replacements that do not have that, and Stainless Steel valves will not.

 

[JacksonAuto]

We used to be opposed to the thick locators and liked to use taller springs, but recent Spintron data has shown that you want the spring as close to coil bind as possible at full lift to take full advantage of the spring rate. This actually reduces fatigue, increases its ability to control the valve and lengthens the life of the spring. We've seen major improvements in terms of throttle response, how smooth an engine runs (particularly at high RPM) as well as increased power output (a direct result of proper valve control, no spring surge, bounce, loft, etc.) when we install the springs to within .060" of coil bind. The spring that Kiggly sells is a PAC spring made for a modular Ford Mustang engine with a shorter installed height so Kiggly added the thick locator to enable them to work on a DSM head. Without it, they've only got 50 or so pounds of pressure on the seat.