I'd like to hear opinions of what you prefer for an engine in a "drag race/ street car"

What is easier on parts? how about costs? etc, etc.

And here's what it applies to. ~4000 vehicle + >450cid + TH400 + GM 8.5" 10 bolt rear end = low ETs

What would you do to make this work?

 

with the set up ya mentioned I would STRONGLY recommend the high torque/low RPM set up. This set up will be easier on the pocket book, bearings, valve springs and pretty much any other moving piece.

The motor that I built for my 55 Chevy (if it ever gets out of the paint shop) is just this type of motor.

.030 over 454 line bored and zero decked
stock 2 bolt block with ARP bolts
stock 3/8 rods with ARP bolts
mini dome pistons (10.2 to 1)
Oval port semi-closed chamber heads with 2.19/1.88 valves
chambers unshrouded a little and are at 106cc
flow #s are 280-285 and 235-240 at .600lift
Lunati flat tappet solid cam
Victor JR and 850 DP

This engine made 545 HP at 5900 RPM and 420 HP at 3000
it made 573 ftlbs of TQ at 4200 and over 520 ftlbs from 3000-6000 on 93 octane. VERY flat TQ curve.
This is a low RPM motor but should work great with the 55 Chevy and shift at 6000-6200 and it will last forever.
Since the paint and body shop was dragging there feet I had time to tear down motor and inspect everything. I have 1 lobe going flat (cam break in and 8 dyno pulls only) so I have a similar spec'd hyd roller to go in but it will never see the dyno. I am not worried about losing/gaining 15 HP with this cam but the flat cam was b/c of the lifter bore not being correct. Using a hyd roller is the only option instead of boring and bushing the lifter bores.

With this combo I was able to use $10 valves, stock 3/8 rods, oval port heads, $130 valvesprings, cheep roller rockers, etc.
The motor could have made more HP with diff heads (more $), Roller cam (more $ for $25 valves, $250 springs, $350 roller rockers, stud girdles, etc, etc.) better rods, better crank, for the higher RPM. I was able to build this engine for less that $4000. That is $350 for 55 chevy headers, $200 for oil pan and pick up, $300 for fluidampr, $70 new flexplate, $200 for ARP bolts, line boring, decking block, etc. This engine could have been built cheeper using some factory pieces instead of these and some of this machine work could have been skipped but I feel the few extra HP and added reliability was worth the extra $.

NightTrain66

 

Torque accelerates vehicles, and if you get decent traction, launching the Imp will require copius amounts. Assuming you don't want a 5000 stall converter for the street, build the engine for best torque in the range you plan to run the engine, say 2500 to 6000.

Yeah, it's generally cheaper, because you don't need rotating parts for 7500 r's.

If you had defined goals, like 1/4 mile times and a budget in mind, it would be easier to make suggestions. 454 big block?

My '96 Imp's plate i s "KLR WHL"

 

no question about it, a big block is all you need. As you've probably noticed the old heavy cars were equiped with big blocks--remember the caddy with the 500 cubic inch engine, a heavier car requires more low end torque to move it. Plus the gobs of torque will allow you to use less gear in the rear, also the big engine doesn't rev as high so theres less stress on the engine. The more RPM you see the greater amount of force is exerted on the rods as they get pulled from both directions

 

I was talking with Bret online about your impy just the other day. We both agree that you need to get it to the track I ran a 13.75 @ 98.4 with just bolt-ons on my stock 117k mile LT1 this sunday

Anyway, this engine won't be for my SS. I'm keeping the LT1 in it to use as a daily driver. This engine is going in my old 91 civi Caprice. The car has cloth bench seats, rear fender skirts, and the softest suspension GM has ever put in a passenger car

Saturday night I bought a stock 2-bolt 454 to rebuild. It needs new pistons, but I think I might be able to reuse the crank and rods. I want to go with as many cubes as I can, but I also don't want to bore the engine out so much that I won't be able to bore it out again on the next rebuild. I think 460 will be fine to start out with.

I've got 2 sets of big oval port heads (open chamber 6272292 or closed chamber 3931063) to choose from. I will get them ported. A friend suggested I go with 2.19/1.88 valves, but I'm thinking of going with 2.25 or 2.3s on the intake. His arguement was lowend torque. I think that with this many cubic inches, torque shouldn't be a problem

I'm definitely going with a roller valvetrain, but I can't decide between hydraulic or solid lifters. I know solid lifters will make more power and torque everywhere, but I am used to hydraulics (just set it, and forget it.) Another friend was always adjusting the lash on his solid lifter 468, and I don't know if I want to do that all the time.

If I can decide on what direction I want to go with this engine, I'll be able to pick out parts so much better. The intake, exhaust, gears, cam, pistons, etc all depend on this.

My goals for this engine are to be able to run, I dunno, maybe 11s on motor in a 4000+ pound car.

My impy has a 3200+ Vigilante + 3.73s and it is very streetable. But the 4L60E has a nice overdrive and lockup for the highway. Another of my goals is to be able to drive to Dallas (120miles each way) comfortably with the big block. I couldn't do that with low gears. The rear end I'll be putting in the Caprice is out of a cop car. It's an 8.5" 10bolt with 3.08s, posi, 30 spline axles, and disc brakes. Changing the gears isn't a big deal, and I'll probably put a locker in.

What intake would you suggest? The guy I bought the 454 from has a Victor Jr for these heads that I could have for a good price. The suggested operating range for those is 3000-7500 and I know I won't be revving over 7 grand. Others have suggested going with a dual plane intake for more torque.

Then there is the issue of deciding what transmission to use. The 700R4 won't hold it for sure and a 4L80E requires a special computer. I'll probably go with a TH400, but another friend has a powerglide with a 3000 stall converter for just a few bills. I will go through it and check the specs, but he said it just got a $500 rebuild.

What I would like to do is turbocharge this beast. That is a way to make tons of torque that is there all the time. Until then, I'll spray it will some nitrous.

But what I will probably do is put on the Victor, Jr. with some 8.5-9.5:1 pistons with the closed chamber heads, and a Comp Xtreme Energy cam to rev up to 6200 or so. Then whenever I get the turbo stuff together, I'll put the open chamber heads on for a bit less compression.

I don't know right not. It's 5:30am, and I'm just rambling on again. I'm tired

 

I would suggest the 2.19/1.88's in the 063 castings. It is a semi-closed chamber and the valves are shrouded enough with out going with the 2.25/2.30 valves.

The Victor JR or the Performer RPM are the 2 intakes to chose from in my opinion. On spray and/or with that stall go with the Victor

just my .02

Nighttrain66

 

Bret has his head full of big blocks recently. Talk with him some more.

There are hydraulic roller grinds which are all you need. I'll guess he'll go with more compression and more intake than the V-Jr.

I don't think the PG is the way to go. I also think it'll take some spray to get into the 11's.

My $02

 

Ive got an impala SS that i just ran a 12.8 on street tires. Trap speeds were 109.5.

Dunno if you want to go faster than that or not, but heres my formula.

383 Stroker
Fully ported LT4 heads
Fully ported LT4 intake
FLP longtubes
SLP True dual exhuast
2800 art carr stall
373 gears
Fully ported f-body MAF
58 mm TB
30 lb/hr injectors with FPR
FIPK CAI

Cam is hydrolic. At valve lift of ~.600, i cant remember the durations. If you want the exact specs shoot me an email and i'll pull out the cam card.

Anyways, that run was made in FULL street trim, no weight reductions, 3/4 tank of gas, and like i said before street tires. It idles very well also. Feel free to email me about anything

 

EDIT: I just read about all the BBC stuff, i skipped over it before, lol. Anyways, 11s are very obtainable with my set up. The 60' was only a 2.0 on the 12.8 run. Pull out some weight, throw on some slicks, remove the belt, front sway bar, your knocking on 11's door

 

I know a little bit about the Impala SS also I'm less than a second from your time, and I haven't even pulled a valve cover off yet. With no posi and the front bar still connected, I could only pull some 1.92s at the track this past weekend :-/ Some day I will probably rebuild my LT1. But until it goes boom, the stock bottom end is staying.

With the Rat, I want mid -high 11s on motor. Nitrous will come soon after. Hopefully a couple big turbos will come after that

 

Low end is this engines strong point, stick with it. High revs in a big block mean strong parts.

HEADS HEADS HEADS, good flow is everything.

I like the LS-6 LS-7 6260482 heads, but they have more port volume and are rectangular port heads.

http://www.sdpc2000.com/cart.asp?act...id=281&pid=216

I would go with a hyrdalic roller. A off the shelf cam like a Comp 11-450-8 or 11-460-8 would be good torque monster cams. Throw some good springs at it and the Hi Tech 1.8 Rockers, and you have .648 lift. It's worth nothing after 6500rpm but then again it's a budget big block. 560ft lbs and 560hp is not bad though. (see the heads below!)

I have been designing a 470cube big block for a few months now. It's a little different from your engine, the big thing is the price. Which is too much.

The funny thing is that there are alot of things in common.
Valve Angles, Intake Manifolds, Rocker Arm Ratio, Hydrallic Roller etc..... all of these things make them pretty close to one another.
Things like the head flow of 420cfm, Valve lift of .700 with 1.7's and little expensive tricks are the things that make them different. That and you are looking at 500-600hp while I am looking @ 800hp+ and the same RPM range 2500-6500.


Most of this is head flow like I said up top.

Check out the World Products Merlin Iron BBC heads, they are what GM should have made. They can be ported to flow even better, and come with 2.25" valves.

http://www.chevyhiperformance.com/ed...0viewtype=text

That page is in my favorites and you should check that out.

Not saying what you have is junk, you just should start with something that is easier to work with, aluminum is much easier but costs more. New seats, guides, valves, etc are probably going to be needed and with a good set of heads that will come with it and then some porting on top of that is a much more effective plan on the budget.

When you spend money do it on the heads. I am working on a LS1 design now. The difference between 30cfm and $1000 is 56hp, that's 9% of the engine's total power lost to heads. Heads then a cam and intake are the most important on build up.

Bret

 

www.transmissioncenter.net/highperflist.htm

They have a well built 4L80 ("Quadzilla") with a reverse manual valvebody, so no computer junk and you'll have an overdrive auto that will last practically forever. The added bonus of having a manual valvebody would certainly be worth the price of admission. I'm gonna try to fit this sucker in my Z28 when I get to building it. Good luck

 

That'd be very nice, but for 3 grand! I'm hoping to get the car running for that much.

 

well, good stuff ain't never cheap