Just a brief update...

Garage is done/signed-off by the county inspectors so I started moving a bunch of crap into it... and finally just brought these two 8.8's home yesterday.

Still need to wire and hang lights on the 1st floor so I can see WTF I'm doing and will be digging into these things in the coming weeks.

Dragracer_Art please contact me
 

Hello Art please contact me my account is to new to be able to message you but please get hold of me i would appreciate it greatly
Thanks John Hawkins @Rolling7s

Dragracer_Art Need Help
 

Trey Ordonez at River Speed and Marine is the guy you need to chat with. He has/had a bunch of these motors and is local to you.

I'd probably sell one of mine @ $2k but Im on opposite side of the country near Atlanta and I've put a little time into them already with teardown/cleanup.

Trey is in Phx and I'm sure has everything you need to slap one together.

https://riverspeed-marine.com/

He has also posted earlier in this thread as Cerberus66

Another update on these 8.8 motors...

I found a set of OEM forged flat tops for one of them, and a new set of Mahle forged flat tops for the other one. The new set are for a 505BBC bore/stroke/rod combo but the dimensions are perfect in a stock bore 8.8 block. Bore is 4.350, rods are 6.7" with a .990 pin and 1.27CH. They are literally "drop-in" pistons and have .0055" skirt clearance.

The OEM flat tops needed valve reliefs in them for peace of mind... so I used an in-head flycutter that worked beautifully.

Havent decided completely yet on which of these is going into the boat. One will be all fuel injected PSI stuff and one will get the 8.1 cathedral port heads and Dart 4bbl intake.

Cant seem to attach pictures for some reason

One more wrench
 

I just picked one of these up that has the LS rockers and beehive springs on it and doesn't have injectors bungs of any kind in the head or intake. It appears to have been ran on propane and could possibly be an industrial application. Also interesting is the smaller diameter push rod on the intake side compared to the exhaust.

Not that it needs it right now, but I'd love to swap one of these into my Suburban. My 8.1 has a little bit of an oil leak that I need to find... maybe the engine needs to come out?? 💡🤔

Plan A
 

That's my plan as well. I mocked up an 8.1 in my square body dually and have been driving it for a couple years. I like it a lot but it's never enough. I plan to install the Raylar heads on my 8.8 and the Whipple supercharger. I'll then bolt that to a 6L90 and put it back in the truck. My plans for the 8.1 involve more Raylar stuff and a 5th gen camaro.

Don't see these engines on ebay now. lol. Word must be getting out.

Just wanted to update this thread I started awhile ago...

I built both of the 8.8's I had. Sold one of them a few months ago and have been dicking around with #2 ever since.
Finally gave up trying to learn Holley EFI tuning and went back to my roots. I pulled the PSI heads and intake so I could replace them with a pair of 8.1 cathedral port heads and Dart intake. Topped it off with a marine 850 and the thing fires immediately at the blip of the starter.

Here's a video I took last night: There are a few videos on my page with it running on the Holley EFI system and also the other 8.8 I built with the Merc 496HO cam. A couple small blocks Idid are on there too.

Sounds healthy!

Which Holley system were you trying to use? I am good with most of them, heck, I helped with their design years ago. I am not sure how I found this thread, I was researching the difference between the GM 454 and 496 and found this engine. Really intrigued. I have a 1996 Dually that needs help. The 454 is tired. A friend is trying to get me to put a 496 in there along with the cooling system and front accessory drive. Now I see this engine. I would really love to hear how you all feel about this engine and what sets it apart from the 496. I can easily stroke my 454 but the stock heads will be a limiting factor, even if I do some porting on them. This is a tow vehicle, will never see north of 5500. I will stick with EFI and yes, it will be running off a Holley Term X Max so I can control the trans also. While I have HP Tuners and know it, I prefer the Holley system.

If you are on Facebook there's a group for these engines called 8.8 PSI big block chevy world. That's the best source of info on the 8.8 we have

It was the Holley Terminator EFI system.
The biggest issue I was having was crank and cam sensor syncing.
I eventually put a flying magnet crank trigger on it and it cleaned up quite a bit... but I still preferred a carb setup... so that is now on the engine and is deadnuts reliable.

I still havent gotten the engine into the boat... and am now rethinking my camshaft choice... Im concerned I may have gone too big with the cam and may have water reversion issues with the stock wet exhaust.
I have a brand new 496HO billet cam on the shelf... so I may play it safe and swap-in the smaller HO cam just for peace of mind.

Hey man, found this post via Google, I have an automotive shop in Winder, and am living in Cleveland currently. I see you sold your spare motor off, but if you wouldn't mind private messaging me (I can't send a PM yet, new member) I'd really like to pick your brain a bit if that's OK. I'm interested in building a frankenmotor for my 8.1 dually. Thanks!

Also, for anybody else - where do you get gaskets for the 8.8?

8.8 fuel rail fit 8.1?

no

psi

https://cimg6.ibsrv.net/gimg/www.off...f00455b7f.jpeg

Stock 8.1, ported 8.8 psi head, raylar head.

It’s an LS head design, but it hasn’t been enlarged enough to support high RPMs with 535 cubes. It’s only got a 2.19” valve. There may be potential there, but you’d be wasting lots of time porting cast iron.

Looks like the stock 8.1 could support 570hp, the ported 8.8 665hp, and the raylar up to 700hp.

Not a lot to love here except the price for a used one. There may be a decent cheap combo to be built with a bigger cam in a stock motor, but otherwise normal aftermarket bbc stuff is a lot better. The 8.1 is not siamesed. The 8.8 head doesn’t look like it can handle high lift or big springs with out mods, according to this guy in the video.

If this guys cnc program is reasonable, and the stock PSI pistons can clear enough cam, there’s potentially a decent cam+head stock bottom end combo possible on the 10/1 compression natural gas version. You might need intake porting to match and fuel system changes to work on gas though.

8.1s have a piston that isn’t ideal and a weak rod. Not sure how the PSI compares here.

An example adding to perspective.

A 454 with Peanut Port heads (70s-80s) that are mildly ported out, will make 570HP at around 5600rpm with 2.19 valves. Reliably.

With low...just over 8:1 CR...and a FT hyd cam.

Popular Hotrodding Mag in 2001..had an article on a 350 SBC ZZ4 Short Block...with 195cc AFR Heads. All off the sheld parts build. Made 520HP at 6600rpm.

PP heads have about a 208CC port...avg 13more CCs than the SBC port...but the BBC port longer...and it really comes down to port CSA. It's a high velocity port when drawn with 454 cubes and some rpm....but they can flow a lot of air.

Well I’d certainly expect it to do better than a peanut port 454 with low compression, even with the same size valve. So maybe the potential is higher. I was just using a CFM rule of thumb, but huge cubes and enough cam could beat the estimate.

I mentioned the PP head 454 specifically because it's a well setup marine engine for no more than 5800rpm. One of the reasons to use a 2.19 int in a PP head...is to fix the GM bore job into the valve throat..destroying any potential to do a proper valve job.

The PSI engines are def an interesting project.

Ported PSI:
[email protected]
[email protected]
Def going to have some potential.