shortblocks

[WayFast84]

I've been thinking about the 84 a lot lately and want to get serious with it. Its got a 2 bolt 400sbc that was supposedly rebuilt and the topend will be getting replaced but that's not been decided yet.

So pretty much I was thinking about a few options:

Blueprint forged shortblock, 355 or 383
Buy a 350 have it rebuilt
Or rebuild the 400(again?)

I don't plan on racing very much while I'm in school but eventually I would like to be at the track a couple times a month which is why I want forged.

Say I run 64cc heads, what pistons would I want in my motor for pump gas? What's the real difference between h beam and I beam rods? If I went with a 383 the heads wouldn't need steamholes because its the design of the 400 block and nothing else, right?

With machine work, assembly, block and parts how much should I expect to pay? Under 4k?

[WildBillyT]

I have heard some interesting things about the blueprint shortblocks. Sub par machine work and wacky parts quality.

Personally, I know you may hate this answer but I'd try and get what you have already going. I remember your engine from years ago and it sounds like a strong runner as-is. That way you can cut your teeth working on it and then when you move on later you can have a more estabished skill set.

[wretched73]

Originally Posted by WildBillyT

I have heard some interesting things about the blueprint shortblocks. Sub par machine work and wacky parts quality.

Personally, I know you may hate this answer but I'd try and get what you have already going. I remember your engine from years ago and it sounds like a strong runner as-is. That way you can cut your teeth working on it and then when you move on later you can have a more estabished skill set.

Id say go with what WBT said. Id also pick up a SBC book so you know how to figure out the calculations to figure out what CR to run etc...

[WayFast84]

The car was faster than my ls1 car. But if it breaks again I'm a couple hundo out of the tube and then have to change the camshaft to something under .480

I changed the rocker arms to 1.5 from the 1.6 I had with no machining but
I beleive the problem is the retainer to guide clearance because the machine shop did not install the drop in springs required and I can no longer find them.

the car needs the valves adjusted and it should run, but I couldn't figure it out and don't want to screw it up since my valvetrain is so sensitive..

[WildBillyT]

Originally Posted by WayFast84

The car was faster than my ls1 car. But if it breaks again I'm a couple hundo out of the tube and then have to change the camshaft to something under .480

I changed the rocker arms to 1.5 from the 1.6 I had with no machining but
I beleive the problem is the retainer to guide clearance because the machine shop did not install the drop in springs required and I can no longer find them.

the car needs the valves adjusted and it should run, but I couldn't figure it out and don't want to screw it up since my valvetrain is so sensitive..

Just for reference, I run the XE268 cam in my Vortec 355.

.477/.480 lift w/ 1.5 rocker. I originally bought an XE274 cam that was .484/.490 but figured that was cutting it too close. Plus the powerband (1600 to 5800) is very good for street use. I also measured and replaced the pushrods and took steps to make sure my valvetrain geometry was good.

Other guys really like the Lunati Voodoo cams. I have heard they run quieter than the XE series but do not have firsthand experience.

[WayFast84]

I thought that was even to close..I have a performer rpm intake, 750 carbed and a 3500rpm stall. Looking for cam specs right now but I think its like .490 .510 112 lsa

So I was close. 234/244 @ .050" .488"/.510", 114 LSA

[WildBillyT]

You may want to pull the heads and have them machined for higher lift just to be safe. I built for low-end grunt and my compression ratio is lower so my motor could not handle too wild of a cam. In your case upgrading the heads to run a larger cam may be well worth it. I think there is a place in New Brunswick that may do it.

[WayFast84]

If the heads come off they are getting replaced, if the motor is fixed and reliable I still want to upgrade a motor so I can paint the car and not worry about if I'm going to have it messed up when the motor is replaced..

I was thinking the retainers are in the top by the valve springs right?

[Slow Z]

Originally Posted by WayFast84

I've been thinking about the 84 a lot lately and want to get serious with it. Its got a 2 bolt 400sbc that was supposedly rebuilt and the topend will be getting replaced but that's not been decided yet.

So pretty much I was thinking about a few options:

Blueprint forged shortblock, 355 or 383
Buy a 350 have it rebuilt
Or rebuild the 400(again?)

I don't plan on racing very much while I'm in school but eventually I would like to be at the track a couple times a month which is why I want forged.

Say I run 64cc heads, what pistons would I want in my motor for pump gas? What's the real difference between h beam and I beam rods? If I went with a 383 the heads wouldn't need steamholes because its the design of the 400 block and nothing else, right?

With machine work, assembly, block and parts how much should I expect to pay? Under 4k?

If you have a 400 short block that is already together and "supposedly" rebuilt, why not just pull the pan off and see what's inside? And if it's all in order, why not just use it? or buy a "cheap" rotating assembly and run it?

My buddy went mid 11's N/A with an almost stock 400 shortblock, unported Vortec heads, and mild solid cam in a car that weighed over 3600lbs.

[WayFast84]

I've seen the motor before. It looked fresh but I don't have receipts and it's still just a cast motor. The heads would most likely be replaced with aluminum vortecs or etecs. I'm sick of having heads off and not making the car any better.

[Slow Z]

Originally Posted by WayFast84

I've seen the motor before. It looked fresh but I don't have receipts and it's still just a cast motor. The heads would most likely be replaced with aluminum vortecs or etecs. I'm sick of having heads off and not making the car any better.

Lets start over here...

What do you want to do with your car? Don't be vague, come up with a specific horsepower or ET goal and list the parts you already have...?

[WayFast84]

My goals are a reliable street/strip car that will go low 12's high 11's n/a and not need a bar. If I never get a dedicated track car I would throw either a 150, 175 or 200 shot on it and have a bar installed.

I'm sure this combo will get me to my goals, just not sure how I am going to get it reliable.

Is it possible I have the valve guides ground down with the heads on the car?

[Slow Z]

Originally Posted by WayFast84

Is it possible I have the valve guides ground down with the heads on the car?

Nope. grinding down the guides literally involves grinding them down which causes a lot of metal shavings... As for 12's you should be able to do that by accident with any 400ci motor with Vortec heads and a cam with more than 210 @ 050 duration.

For as long as I can remember you've been talking about this Vortec headed 400. Has it ever made it down the track? No offense here, but maybe you should take it to someone that knows what they're doing before dumping any more parts into it?

[WildBillyT]

Originally Posted by Slow Z

As for 12's you should be able to do that by accident with any 400ci motor with Vortec heads and a cam with more than 210 @ 050 duration.

Actually made me LOL. Quoted for truth.

[WayFast84]

It's never held together long enough to get to the track.. Ive had it to numerous shops. one of them had the cylinder heads cleaned decked and reinstalled them(they never noticed a problem). It's why I don't want to really waste any more cash here and put together a new motor with heads that are good out of the box.

[WildBillyT]

Originally Posted by WayFast84

It's never held together long enough to get to the track.. Ive had it to numerous shops. one of them had the cylinder heads cleaned decked and reinstalled them(they never noticed a problem). It's why I don't want to really waste any more cash here and put together a new motor with heads that are good out of the box.

Re-buying parts when what you have now would work well is wasting cash, too...

[Slow Z]

what exactly is the current problem? I'm getting you believe you have valve guide-to-retainer interference? Can you explain what the motor is doing to lead you to this conclusion?

[WayFast84]

First I popped a pushrod, replaced all of them and had a Rocker stud break, had a shop check everything out, and the car ran fan for maybe 100 miles if that and popped another stud. I replaced the 1.6 rockers with 1.5, and even have stud girdles but I want to know for a fact I fixed the problem this final time.

here is from nastyz28's sticky

Originally Posted by Dirt Reynolds

[*]Retainer to guide clearance is the primary Achille's Heel of the Vortec. For valve lifts above .460" they need to be checked for R-G clearance. This varies from head to head. Some find they can get .480" and slightly more valve lift fine. Others will find .460" about the limit. Always check R-G with any performance cam above .460".[/LIST]Great, I'm interested in Vortec heads, but am concerned about retainer to guide clearance. What can be done about this, and, are there any places I can buy Vortecs already modified for use with high-lift camshafts?

Good question, easy answer.

Scoggin-Dickey sells Vortec heads already correctly modified for use with high-lift performance camshafts. They also sell a complete kit which has the modified Vortecs, intake manifold (Edelbrock Vortec), rocker arms, etc to basically bolted on your existing short block.

Sallee Chevrolet has an interesting solution to this problem (from their website):

The Sallee Chevrolet solution is to use Crane Cam’s 10309-1 drop-in valve spring and retainer kit which is good for .550” lift with no machining. The installed height for this Crane Cams kit is taller and the lower part of the retainer is shorter. The “AVERAGE” clearance between the retainer and seal is .575” for this kit. We have found that some of the Vortec heads, coming from the factory, do not have the valve seals driven on all the way. You need to check that they are before installing this kit. If they need to be driven on all the way, we have found that a 3/8” drive - 1/2” socket fits the valve seal just about perfect.As with all modifications to performance engines though, you should always measure to assure that there is proper clearance and fit.

Comp Cams sells a tool that will cut down the size of the Vortec valve guide and is around $50 or so.

Another method is the infamous Vortec retainer "ghetto grind". If the camshaft being used only requires a stock 1.25" diameter single-wound valvespring, it is possible to only need to grind off approximately 3/32" off the bottoms of the stock Vortec retainers with a grinder or on a grinding wheel to achieve enough R-G clearance to run up to approximately .530" -.540" safely. I must caution here that R-G clearance must ALWAYS be checked to verify that there is in fact enough clearance - also include allowing for coil bind. One other thing - you must remove the dampner in this modification. Don't worry -- the stock Vortec valveguide being much larger in diameter than other SB heads will act as sort of a dampner and I never noticed any RPM issues related to lack of running one when I did this mod. Although myself and others who have done it this way have had no problems, I must caution this basically for those on a strict budget and cutting down the guides either with the Comp tool or at a machine shop is the best way to go. However, I'm of the opinion that since it works well within the noted constraints, then you're really only out your time to grind down the retainers. The choice is yours.

More to follow.

What is the best option here? Assuming I can locate the springs.

[Slow Z]

what does your entire valvetrain consist of?

cam?

springs?

rockers?

what has been modified on the vortecs?

You absolutely have some sort of geometry issue here.

[WayFast84]

Cam is above. Vortecs have screw ins(thank god!), steam holes and the springs installed(I think these and the retainer to guide) is the problem. They are huge springs and I have to find the box when I am home. I had 1.6 roller tips, self aligning when these problems happened. I now have 1.5.