bogus wrote:
This seems to answer a question that really didn't need to be asked. I don't see the point in it.

Durango_Boy wrote:
I'm building a roller 405 out of my Gen1 400, and I'm expecting near 450 FW HP from my combo.

anesthes wrote:
Quote:

Durango_Boy wrote:
I'm building a roller 405 out of my Gen1 400, and I'm expecting near 450 FW HP from my combo.

What is the combo?

-- Joe

Durango_Boy wrote:
Quote:

anesthes wrote:
Quote:

Durango_Boy wrote:
I'm building a roller 405 out of my Gen1 400, and I'm expecting near 450 FW HP from my combo.

What is the combo?

-- Joe

SBC 400

Front Pad: T10140SA
Casting: 3951511
Date: J12-72

Compression Ratio Data

Bore Size - 4.145"
Piston Stroke - 3.75"
Head Gasket Bore - 4.190"
Compressed Gasket Thickness - 0.038"
Chamber Volume - 64cc
Dish Volume - 12.5cc
Deck Clearance - 0.025"

Estimated SCR - 10.15:1

405 ci (Bored +.020)
6.638 liters per cyl.
6633.85 CCs
Retrofitted for V6 Hydraulic Roller Lifters
5.7" Rods
12.5cc Dish Speed Pro Pistons

COMP CAMS SBC 288 XTREME ENERGY HYD. ROLLER CAM #12-433-8

64cc chamber/ 190cc Intake Runner Aluminum Vortec Heads .600" Springs
Self Aligning Roller Rockers
Vortec Air Gap Intake Manifold

Hrmm. Sounds good.

V6 hydraulic roller lifters huh? I saw a thread on this on thirdgen a couple years back. Is it reliable?

I myself and thinking of 400 based motor, though my target would be closer to 500-520hp.

-- Joe

Durango_Boy wrote:
Quote:

Hrmm. Sounds good.

V6 hydraulic roller lifters huh? I saw a thread on this on thirdgen a couple years back. Is it reliable?

I myself and thinking of 400 based motor, though my target would be closer to 500-520hp.

-- Joe

Yeah I personally think the stock style retainers are more reliable than link bar setups. I've seen way too many of those link bars fail...which leads to disaster. The dog bone retainers would only fail if there was an oil starvation issue. The lifters themselves would be the same, since there are only a handful of manufacturers and all vendors use those same lifters including factory applications.

The only thing that I didn't notice the other day that I'd like to give you a word of advise on is your deck height. .025" + .038" is way too much. You want to keep it around .040-.045" total for good quench. Assuming your pistons actually put your clearance at .025", that would be more for a shim gasket of around .020".

mechguy79 wrote:
First...I apologize if this is a repeat question. I tried searching and didn't find much. I read this article a while ago and can't get it out of my head:

http://www.purplesagetradingpost.com/ ... 350%20chevy%20engine.html

I really like this idea, and I wanted to hit you guys up and see what you thought. Plus's, minus's, plain ol' dumb? Thanks all.

Durango_Boy wrote:

Joe I actually went from the thin gasket to the one I picked for compression. I know the quench is now a bit large but my compression is 10.15:1. Any thinner and I will be into 93, and there just aren't many places that sell that around here. I'd be locked in Columbia with no way to travel without a trailer. Not only that but the higher compression would detract from what streetability I was trying to keep.

I had a long talk with the Comp guys and after going over my engine specs and going over what I was looking for out of this engine they came to the final suggestion of the XR288HR. I enjoyed talking to their techs. Very friendly with a lot of knowledge to back everything up.

Keep in mind, a 10.15:1 motor with aluminum heads has about the same octane requirements as a 9.5:1 motor with iron heads.

I agree, the comp cams guys are great.

How is the cam to rod clearance? That is the only thing I'm worried about. I think I'm gonna run the XR288HR cam too.

The pistons I'm using are the 16.2cc reverse dome, with a .044" quench I'm looking at around 10.4:1 compression ratio on some 250+ cfm 64cc heads. On good gas that should translate to a hair over 500hp.

Durango_Boy wrote:


I'll re-crunch the numbers and see what I get. The other issue I was running into was that a good quality head gasket, thin enough, with steam holes for the 400, AND compatible with aluminum heads...was hard to find.

I haven't stabbed the cam in the engine yet but I am anticipating rod bolt clearance issues. I am planning to wrap the lobes with a layer of painter's masking tape to guard against nicks, and check for tolerances. I expect I will have to grind at least 4 rod bolts, maybe all 8.

If you didn't purchase the cam already, comp can do the same grind on a smaller base circle for the same cost.

-- Joe

Durango_Boy wrote:
Quote:

If you didn't purchase the cam already, comp can do the same grind on a smaller base circle for the same cost.

-- Joe

I actually already had this cam in a small base circle for strokers. I had to sell it to get the money back for the larger base circle. The reason is because of the V6 lifters I am using for the roller retrofit. The small base circle cam allows the lifters to fall much further into the lifter bore, keep the oil feed hole unsealed and in constant contact with the oil feed. Not only that but when they were down fully they would come completely out of the bottom of the retainer.

I figured it was easier to just go back to a larger base circle cam, and deal with grinding the rod bolts.

The v6 lifters are shorter than the v8, right? I wonder if using the v8 lifters is possible with the smaller base circle, without lubrication failures..

The only thing I don't like is the drilling and inserting studs into the lifter valley to hold the spider retainer down. I just feel like you risk something eventually backing out. Not that it's much different than OEM...

Where do you expect your peak HP ? Around 5700-5800 or so?

-- Joe

Durango_Boy wrote:

Yeah the V6 lifters are shorter, so with a standard base circle they are PERFECT. The V8 lifters, even on a small base circle cam, still sit a bit low. The oil feed hole never comes completely out of the feed, and therefor can't seal against the side of the lifter bore.

The material at the top of that lifter valley where I drilled the holes was quite thick, and I used lock washers AND a jamb nut. I don't think the studs are going anywhere.

With my Air Gap manifold, 288 cam, and hopefully the twin side draft carbs, I'm thinking peak HP will be around 5700, though I won't go that high very often. I prefer utilizing the lower RPM band and playing with the torque...as I'm expecting will be quite substantial with the 405.

What is the rough cost of the v6 lifters?

You also have to drill and install a retainer plate, right? and then use a timing set for a 87+ roller block?

-- Joe

Durango_Boy wrote:

Well there are a few ways to go for the V6 lifters. You can source them from salvage yard V6 engines...very cheap. Used lifters are fine so long as the they were properly oiled throughout their life and the roller surface isn't marred.

I found mine on Ebay, a set of new lifters for $50, and I had to buy four more new ones locally which was more per lifter.

If you bought all 16 new at a local parts store you'll pay over $200 for just the lifters. I have leftover retainers and the hold down spider bar if you get to needing them, let me know.

They make roller cams specifically for retrofit applications now so they have the flat nose as opposed to the later model step nose. For this reason all you need is a cam button to keep the cam from walking. As far as I know, it's not feasible to machine the front of the block to accept a late model retainer plate for step nose cams and timing sets. I don't even know if it would all line up right mixing and matching.

I got a two piece timing cover that has a removable cam plate and integrated cam button. Very handy.

Durango_Boy wrote:
When I performed this mod I didn't think to take many pictures. The drilling is super easy. mark the holes using the spider bar. Drill pilot holes. Drill sized holes. Tap holes. Cut studs to length, use jamb nuts and lock washers to space the spider bar up to simulate the bosses cast into the late blocks, and that's it.

Don't forget though that you will have to use a die grinder and a diamond bit to clearance around the tops of the lifters bores so the retainers sit perfectly flat. As it is there is some extra casting around the walls of the lifter valley that keeps them from sitting flat.

On a 350 this doesn't equal much clearancing but on my 400 there was quite a bit more extra casting.

anesthes wrote:

Due to rod clearance, I need to go with a small base circle cam on my 412. (double checked). Too close for comfort.

-- Joe

rklessdriver wrote:
I have never liked the 60* V-6 hy roller lifter deal. It's a neat way to use parts from an otherwise completely worthless engine family but it has some potential problems I would rather just not deal with.

Something about drilling for the tie bar retiner (spyder) and then having the tie bars (dog bones) sitting on the unmachined/as cast top of the lifter bore just doesn't sit well with me in any hi-performance application. Also depending on the base circle of the camshaft the oil band is not really in the right place and you could end up relying on oil seeping thru the lifter bore clearance to get oil to the topend...

Now add in the fact that good retro fit hyd roller lifters are getting cheaper all the time....

http://www.competitionproducts.com/prodinfo.asp?number=91164

When you add in how much labor it is to do all that iffy work to make 60* V-6 lifters work in a SBC you almost at the point of diminishing return considering the retro fit vertical tie bar lifters are a proven hi-performance part. The only ones I've seen fail were owned by morons who didn't have enough spring pressure to control the valve train at the RPM they were turning and vlave float/lifter bounce destroyed them. The retro fit lifters are heavy and in a SBC you needed around 145 lbs/380 lbs to turn 6500RPM with them on a decent cam profile back in the mid 90's. Todays hyd roller profiles have come a long way with the opening/closing ramps so you may get away with a little less spring if you utilize the newer grinds.
Will

anesthes wrote:
Hey Brian,

That's impressive.. I can't tell from the pictures, is that a steel roller cam or a cast iron flat tappet? The lobes don't look aggressive.

-- Joe

Guys put a .015" feeler gauge between the roller and the valve (rocker), then crank the lifter down (at TDC) until the plunger bottoms out. Remove the feeler and you have exactly .015" clearance in the plunger on every lifter, rather than trying to get a specific preload.

rklessdriver wrote:

Joe
I have used this valve adjustment on hyd rollers a few times in the past - but it really only mask the problem.

With all the work I've put into mine in the past 2yrs (almost), I'm begining to dislike hyd rollers for serious hi-performance engines more and more everyday. Once you get to a certian point it is knives edge balancing act of valve spring, lobe rate and external stability. You get one bit out of kilter in any one of them and the whole shebang goes to hell....

I like mech rollers. If you have good oil supply at the lifter wheel and valve springs a mech roller will live a very long time. A tight lash lobe profile will go a long way to keeping the valve adjustment in check - which is the only other big killer of mech roller parts I have seen. With the HIPPO (MOREL and CROWER) lifters and spring oiler V/C or shaft mount rockers we have now I think one could make a mech roller live forever in a street car.

I'll tell you what... If that fricken hyd roller in my 92 eats one more set of valve springs, I'm going to switch my car over to a T/L mech roller and find out.
Will

BrianCunningham wrote:


Ouch, not a fan of reduced base circle cams.

I've seen too many snap on road courses

anesthes wrote:
Quote:

BrianCunningham wrote:


Ouch, not a fan of reduced base circle cams.

I've seen too many snap on road courses

Did some research on this.

The "smaller base circle" translates into a literal smaller lobe. The core of the camshaft is the same diameter, same with bearing journals and all that.

I can't see why having smaller lobes would case a core to break like that..

-- Joe

Durango_Boy wrote:


Last time I saw a snapped cam like that it was a very aggressive cam being abused in an engine that didn't have perfectly straight cam bore. It was off just enough that before it was checked he snapped two or three cams.