I am looking at either the 454 HO or ZZ454 crate motors from GMPP. With plans to put a procharger on later, which would be better? The HO is 8.75 CR with iron heads and the ZZ454 is 9.6 CR with aluminum heads. I am looking for around 700hp after the procharger and a cam swap. Which would be a better starting point for pump gas? Thanks for any advice.
454 HO or ZZ454, which is better for a procharger?
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Either one will work, I would stick with the lower comp. however the aluminum heads would l help offset that. But either one to run any amount of boost it will need to be intercooled on pump gas. Personally I would build an iron headed 8:1 496 for what those crate motors cost. then put on a d1sc or an f1 if you want to make some good HP. Either way you will have a huge grin. A local car here with a f2 and a 540 runs in the mid 8's at 150+ in a 10"tire street car, with leaf springs. I would love to build one myself but that initial investment is so hard to part with. Also will you be running EFI or blowthru carb. As this will also determine boost limits and compression.
I am going to run blowthru, the EFI I have seen is too high $$$. I was interested in the iron headed motor because of the low compression, but I have read a few times that the centrifugal blowers work well with around 9.5 CR, and the aluminum should help keep detonation away. That seems like high CR, but I dont know. Thanks
I think you could get away with either one. And will easily attain your power goals, 750 blowthru carb, intercooled and about 10 psi of boost. Also remember you will need a fuel pump capable of fuel psi + boost psi and a boost referenced regulator. You might want a boost referenced timing retard to push it a little harder.
Either one will work, but out of the crate, the alum head motor has much better exhaust ports. For a boosted motor is it may be a mute point depending on how much overlap you have. 10 psi will not only fill a cylinder it will also scavenge it. If you go with the 454HO, my suggestion is pull the heads before you ever install it, do some basic bowl clean up and any machining the guides for PC type seals. Also cut the guides for more lift while apart.
I might go with a 3rd option. For $6300 I could get the 454 HO shortblock from Sallee, choose my own Dart or Brodix open chamber heads, choose my manifold, and just go with a flat tappet blower or nitrous cam. Thats only $600 more than the ZZ454 and it would probably be better customized for a Procharger.
Bustin in... Anybody know how good the bottom ends are REALLY on the HO or ZZ? The cranks are Forged 1053 and the rods are forged 4340 and also has forged pistons. How are the springs, retainers ect on the heads? I know I would change the crank cap bolts to studs and the head bolts to studs. How are the rings for a blower and how much HP can this engine take?
From what i understand ... all things being equal you gain ~10% torque gain per point of compression and ~15-16% per pound of boost. Therefore you can get more power out of the same combo by starting with a lower base static compression and adding boost than starting with a higher static compression and adding less boost. That is why you see most purpose build turbo/supercharged engines with a lower static compression ratio. The "magic" number seems to be ~8:1. The reason they don't go with an even lower static compression is the engine has to be able to run/idle reasonably off-boost.
On the starting engine side.... i would talk to some of the guys that run machine shops on the board(Mike aka Wolfplace comes to mind). I did some really quick math.... even starting with all new aftermarket block and rotating assembly I am sure you could get more bang for your buck having something build for the $6.5K you are thinking of spending on a shortblock.
If it was me I would have something built with a forged bottom end(crank, rods and pistons). Dish HD blower/turbo pistons would be the best way to go. Aim for a starting static compression ratio of 8:1. With and intercooler you could easily run 15psi+ on pump gas. Get some of the cam guys to recommendation on a cam ... be careful of Lobe displacement angle (LDA)--115 degrees is not uncommon to reduce overlap.
It would be a monster. I would like to see you hook it on the street. Would be a hell of alot of fun though.
Just my 2c
T.
On the starting engine side.... i would talk to some of the guys that run machine shops on the board(Mike aka Wolfplace comes to mind). I did some really quick math.... even starting with all new aftermarket block and rotating assembly I am sure you could get more bang for your buck having something build for the $6.5K you are thinking of spending on a shortblock.
If it was me I would have something built with a forged bottom end(crank, rods and pistons). Dish HD blower/turbo pistons would be the best way to go. Aim for a starting static compression ratio of 8:1. With and intercooler you could easily run 15psi+ on pump gas. Get some of the cam guys to recommendation on a cam ... be careful of Lobe displacement angle (LDA)--115 degrees is not uncommon to reduce overlap.
It would be a monster. I would like to see you hook it on the street. Would be a hell of alot of fun though.
Just my 2c
T.
a steel crank,forged flat top 454 with ported 049 or 781 heads would be more than stout for a boosted big block.
Heck,if an 8.0 to 1 Buick 231 V6 can handle 16-18 lbs. of boost on 93 octane,a 454 built as I mentioned is more than adequate
Heck,if an 8.0 to 1 Buick 231 V6 can handle 16-18 lbs. of boost on 93 octane,a 454 built as I mentioned is more than adequate
Here's my Procharged combo for comparisons:
.030 over 454, stock 2-bolt block with ARP studs
stock cast crank, stock 3/8 rods
TRW L2465 Pistons ~ 9.6:1 compression
Comp NX284 nitrous cam
Non-ported 241 oval ports with 2.19/1.88 valves
800 cfm Holley modified by Sd Concepts
Old Procharger P600b without an intercooler
I ran on pump gas and never had a problem on the street, I would run 104 race gas or add in some 110 when racing. If I would have had an intercooler I would have stuck with pump gas. I ran this combo for 4 year and ran 10.67 letting off and 128.5 mph on anther pass in a 3800lb '69. My Aeromotive fuel pump quit while going down the track in July and I burnt holes in all the pistons. I beefed up the bottom end of the block and I'm going to add a 4.25 stroke 4340 crank, rods, and flat top pistons. I'll run my existing heads and cam and add an F1R or F2 with intercooler and hopefully make an easy 800 rwhp.
.030 over 454, stock 2-bolt block with ARP studs
stock cast crank, stock 3/8 rods
TRW L2465 Pistons ~ 9.6:1 compression
Comp NX284 nitrous cam
Non-ported 241 oval ports with 2.19/1.88 valves
800 cfm Holley modified by Sd Concepts
Old Procharger P600b without an intercooler
I ran on pump gas and never had a problem on the street, I would run 104 race gas or add in some 110 when racing. If I would have had an intercooler I would have stuck with pump gas. I ran this combo for 4 year and ran 10.67 letting off and 128.5 mph on anther pass in a 3800lb '69. My Aeromotive fuel pump quit while going down the track in July and I burnt holes in all the pistons. I beefed up the bottom end of the block and I'm going to add a 4.25 stroke 4340 crank, rods, and flat top pistons. I'll run my existing heads and cam and add an F1R or F2 with intercooler and hopefully make an easy 800 rwhp.
Personally, if I were going to spend that kind of money, I would build my own with whatever components I wanted in it. All forged Eagle or Scat rotating assemblies are about $1750.00. You should be able to find a block for a couple hundred. Have it machined and balanced by a good machine shop. Put any heads you want, from 781's with big valves to Edelbrocks or Brodix RR. Build it the way YOU want it, not the way GM wants to sell them. Just my opinion.
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