454 goal and potential??

Grumpy · Sep 27, 2015

Chevynovass said:
So heres the backstory. About 10 or 12 years ago I stumbled upon a 454 sitting in a bag under a quilt in an older gentleman's garage. I asked him about it and he had most of the receipts and said "its brand new" which it was. It had just come back from a reputable shop that did the machine work and built it. Was bored 30, new cam bearings, and everything else was stock rebuild. They used flat tops with 2 valve reliefs and from my searching with the 049 heads on it i gather about 7.8 or 8 to 1 in compression. This motor was going to be for a nova but i got a killer deal and built my own small black for that. My uncle who got me into cars was getting ready to start restoring a chevelle that he had, he had always wanted a rat but never had one. So i gave my 454 to him, as much as he had done for me (he is the reason i got into cars at a young age, even bought my nova) it was the least i could do. Well shortly after his health went down and recently passed away. Im pretty bummed that its a project he didnt finish, so I feel very strongly that I want to get this rat up and going and in my nova. Im not too worried about the trans and rear, i can handle that stuff but the BBC portion is very new to me.

Goals, streetable but powerful. My SBC in the car now makes 370 hp at the flywheel and runs on pump gas. So i would like to at least stay at those levels. From all of the reading ive done it seems the low compression is going to be my weak link. Even though everything was rebuilt years ago, it has been oiled and its in perfect condition. I will probably replace some selas and do plan on pulling the heads just to look at everything.

My questions, can i hit 400 with the flat tops? Im ok with buying a new set of pistons, but really dont have the cash to go into new heads, cranks or rods. Would it just be a better starting point to get some domes, any suggestions there? I will be picking the engine up in the next month or two. I have an aluminum intake and even though it may not be the best i have a 780 holley to go on top. I know this is vague, and I have done the research but know there are some guys here that could say get XXX piston and XXX cam and your good to go. Im not looking to rewrite engine building or try something crazy but want something that would make my uncle smile if he was in it and i pushed the go pedal. Thanks for any help

rectangle port heads generally work best on 500 or larger displacement engines
with at least 10:1 compression and cams with at least 245 duration at .050 lift and valve lifts over .600 to take advantage of the potential port flow rates

BlackoutSteve posted these pictures
What cylinder head?
With my 4.280" bore and AFR head, I am forced to use a 4.540" bore gasket because the chambers are wide and would otherwise allow the gasket to "hang" in the chamber.

For example..

the reduced diameter of beehive valve springs usually eliminates the rocker too retainer clearance issue

mark iv blocks

mark v blocks

(keep in mind that ALL '91 and later Gen.V and Gen.VI big blocks come with 4-bolt main caps. The two-bolt big blocks are no longer in production
MANY BUT NOT ALL aftermarket head designs have been modified to work on both the early MARK IV 1965-90 and later MARK V & VI blocks 1991-later.)
BTW, , on BIG BLOCKS the oil pumps and oil filter adapters are different due to the block oil filter recess and rear seals being different
GEN 4 or MARK IV

GEN V and VI

coolant holes in factory heads match factory blocks of similar version, aftermarket heads usually tend to have a universal coolant passage design that will function on most blocks but you need to verify and use the correct head gaskets

INVESTING THE TIME AND EFFORT IN PURCHASING AND READING A FEW BOOKS WILL BE VERY COST EFFECTIVE
a couple days of reading and asking detailed questions can save you thousands of dollars, and months of work
the 049 BBC heads are a very good starting point,theres no reason to not use those and you might be rather surprised at the power level you potentially can reach with those heads mildly ported,
which YOU can easily do.

I build mostly big block engines so here's some basic info, don,t make the very common mistake of over caming the lower compression engine,and doing a compression test might be a good idea to verify the engines current condition.
when you have detailed questions , or want specific suggestions post them and we will go through the answers in detail.
many guys ignore proven combos, because it may cost more than they want to spend, and either insist on using components they own currently or think they can buy far less expensively than the components, I know from experience will actually work.

read these links
http://www.maliburacing.com/patrick_budd_article.htm

http://garage.grumpysperformance.com/index.php?threads/a-mid-range-454-bbc-build.8215/

http://garage.grumpysperformance.com/index.php?threads/cheaper-454-chevy-build.4620/

http://garage.grumpysperformance.co...ting-big-block-chevy-454-cam-dyno-test.10181/

http://www.chevyhardcore.com/tech-s...ci-big-block-comparing-l88-zl1-zz427-engines/

http://garage.grumpysperformance.co...-building-a-peanut-port-big-block-combo.2900/

http://garage.grumpysperformance.com/index.php?threads/basic-lower-cost-big-block-build.10502/

http://garage.grumpysperformance.com/index.php?threads/big-block-or-ls-series-motor.6866/

http://www.superchevy.com/how-to/project-cars/sucp-1208-big-block-heads-shootout-the-o-vs-r/

https://www.airflowresearch.com/westech_figures.php

http://www.hotrod.com/how-to/engine/ccrp-1211-rectangle-vs-oval-port-big-block-test/

http://www.wallaceracing.com/Calculators.htm

http://www.superchevy.com/how-to/en...206-oval-port-big-block-chevy-cylinder-heads/

http://www.hotrod.com/how-to/engine/0906phr-10-questions-chevy-big-block/

http://www.superchevy.com/how-to/80341-affordable-chevrolet-small-block/

Dr J' Performance 496 049 head dyno test
Hey gang there his been a lot of talk around here about how much power you can make with a set of 049 oval port heads. I've been planing to see what we could do with a build up like this for a long time but its just been a side project at the shop. So my goal was to see how much power we could make with a small budget and a set of ported 049's all on pump gas. So we went to westech yesterday to dyno the engine and things went good but not great. we broke in the engine and every thing was going fine the engine sounded great and every thing looked fine. So we drained oil re-tq'ed the heads and set the valve lash. We made a the first real pull and everyone was surprised to see the results 730 hp at 6400 rpm and 654 ft lbs at 5100, at this point we had not touched the carb and there was only 30* of timing. We made a quick back up pull and to verify the number and they were right on. But here's where the problems started, after the back up pull the engine was idling and all of a sudden the oil pressure dropped off

. After a lot of speculation on the dyno we got the engine back to shop and tore it down. The budget crank we were convinced would not be a problem was out of round in the 3 center main journals and wiped out the main bearings. It's the first time I've used a crank based on the price savings and will never to that again!!! Well that's the story, I plan to rebuild it and go back to dyno and see what the engine can really do.

The engine was tested with 2 1/8 dyno headers and had 30* of timing

Dr J's Pump Gas 496

4.310 bore X 4.25 stroke
6.385 rod
SRP Pistons 11.68 to 1
Comp solid roller 263 @ .50 on the intake and exhaust .734 lift
1.7 comp pro magnum rockers
Dart 4500 single plane oval port intake
1050 dominator

Head flow
BBC Open Chamber Large Oval Port #049

Ported Intake
.100 76 cfm
.200 152 cfm
.300 228 cfm
.400 271 cfm
.500 315 cfm
.600 341 cfm
.700 348 cfm

Dr J's Ported Exh

.100 68 cfm
.200 134 cfm
.300 162 cfm
.400 214 cfm
.500 242 cfm
.600 261cfm
.700 289 cfm
Intake Valve ported 2.25 Exhaust valve ported 1.94
( Exh. Flow Tested with a Flow Pipe 2" x 3" long) *Flow tested at 28 inches

philly · Sep 27, 2015

that dr j's 496 seems like a stout little motor... i wonder why the dr j's site stopped selling cylinder head porting tools and equipment.

philly · Sep 27, 2015

so i did some quick googling and apparently bruce who owns dr j's stole from, sold, and did not pay tribute to roger helgesen for all of the porting stuff, even stole his flow bench and digital maps of runners to cnc and pawn off as his own while roger was dying. if the name roger helgesen doesnt immediately ring a bell read a david vizard book hes mentioned as a source of information on almost every page that relates to cylinder heads.

philly · Sep 27, 2015

to the tune of $15k

Indycars · Sep 28, 2015

When did this happen? I didn't find Dr J's selling anything when I was looking for sources 2-3 years ago.

454 goal and potential??

Grumpy

The Grumpy Grease Monkey mechanical engineer.

philly

solid fixture here in the forum

philly

solid fixture here in the forum

philly

solid fixture here in the forum

Indycars

Administrator