85 coachman small block chevy

[85antique]

Hi all new here new to forum i have a 1985 coachman 23' mh on a g30 chassis we got it 3 yrs ago and have renovated the inside.
Wifie made all new curtains rebuilt bed now full size normal bed with storage under tile floors threw-out redid bathroom installed full tub ( why a half tub w/ seat was in it) rebuilt the bunk over cab will have pics when i figure out how to do it. Here is my question i have looked all over and it is like no one has a small block 350 powered motor home it has run good for us and we pull a 20' car trailer with a dragster it is slow up hill but makes it we put A new trans in it last yr this years upgrade is a new motor 383 stroker built for torque chassis has 134000 on it and every gasket leaked so it was time

So any other under powered owners out there???

[85antique]

Pics before and after

[85antique]

More pics she was a cream-puff when we got her

[fleamarketer]

1. Not coming on here as a internet hero.This 383 build is a result of 50 yrs of drag racing and well over 30 yrs buying and selling SBC parts as a swap meet vendor.I posted in my intro that I am a fleamarket vendor and that is a off shoot of the swap meet vendor.
   
   The carefully selected parts here is by no means a mistake.It is based on the business of high performance parts and the intended use of this engine being a tow engine with tons of torque and a fun ride too.And torque is king for the towing part of it and the street.
   
   There are bottom of the barrel stroker kits out there that have a long history of issues.One brand name that we will never buy,infer,suggest to anyone is Eagle.The cranks QC is horrible.Found to have broken behind number two main journal and out of the box bearing journals with tapper so bad requires a 10/10 cut to get even close.Guys this is a off shore company that forges there stuff off shore and machined off shore as well.Buyer beware.
   
   This whole thing started as me buying a donor vehicle which had a 1995 "crate engine" with less than 100,000 miles on it.The term crate engine as you guys know can and do mean a number of different things in terms of quality.It was a running engine with no noises.So I opened it up just to reseal it.Thought I wanted to check the bearings while I was at it and I am glad I did.The rod bearings where badly worn.So a decision was made to turn it into a 383.
   
   The block:
   
   1995 bored .030 over and decked .010 down for a better SCR(static compression ratio) and acceptance of today's gas.It will be used as a hydro roller.
   
   The pistons:
   
   For the longest time I debated with myself if I wanted to buy custom Howards forged pistons.If you look around you find the whole market is geared towards performance SCR's as well it should be.But if you want to build a middle of the road engine it is alot tougher to do that.Wanted to build into this engine long term reliability and more than I will ever use,we decided to use the 5.7 rod Icon -18 cc dished forged pistons.The 5.7 rod pistons because I didn't want to have to deal with rod pin location/ring spacers on the street driven vehicle.One nice feature about the design of these pistons is they have a off-set pin location which helps limit cold forge piston slap.
   
   
   
   
   
   
   
   The rods:
   
   Although Scat's cranks in there stroker kits have issues,the rods are a big bang for there buck.We selected stroker clearanced ARP bolt 5.7 press fitted rods.Here I wanted to say there isn't any performance advantage in full floater pistons unless your going to change pistons all the time.Also by choosing press fit pistons your not going down the road deal with worn out rod bushings.We put these rods threw a strict inspection and found them to pass easily.
   
   
   
   The crank:
   
   For everything I have said about crankshaft certainly we wanted a solid well done pc.We found that in A company called Howards which is forged here and machined here perfectly round with tight QC controls.We bought the last 5.7 forged crank from them because all that is available now as a crank alone is ones for a 6" rod.It has two lightening holes too.
   
   
   
   
   
   Because this is a two pc crank going into a one pc block it requires a adapter and what your see here is the pistons mounted on the rods as well.What is left to get for a short block is kings "H" bearings.
   
   
   
   The Heads:
   
   What is planed for the heads is 180cc intake runner 72cc Iron Eagles cut down to 67cc's for a end SCR of 9.3ish with a .040 head gasket.We are going to use a yet to be determined aftermarket EFI.
   
   The dyno Sym is with a custom ground roller hydro cam looks like this:
   
   RPM HP TQ
   1000 88 461
   1500 149 521
   2000 204 535
   2500 247 520
   3000 289 506
   3500 319 478
   4000 346 455
   4500 357 417
   5000 348 366
   5500 319 305
   
   Thanks for looking,
   
   Gary

   
   
   

[fleamarketer]

Now all the above being said,your 350 in that P30 is 190ish hp.It has a 4.11 rear end gear ratio.GM offered a 454 in that chassis with the same 400 tranny and dual rear wheeled rear end with 4.56 rear end gears.For one thing the dual rear wheeled rear end would offer a more stable towing M/H and it is alot easier to get more out of a 454.The difference in the short run looks like the SBC would be cheaper to put together and would get better gas mileage,but if you build a reliable quality bottom end stroker 383 the dollars are close and because it is a motor home,the gas mileage would end up being close too.
The other thing to consider when building a 383<yeah I regret not going that way>is a primary question.Which would you rather have??. A first gen .030 over 350 block or for only another $1,400 a SHP 4.125 block that in every-way is tons better.The bigger bore..........right??.It just makes more sense when you consider the big picture not costing that much more.

[fleamarketer]

As I am thinking about this more,your going to want a torquer engine at as low a RPM as you can get it.It is kind of one reason why I am suggesting a 454 and there is a boat load of them out there.Maybe a good find in a 454 would be later yrs a hydro roller cam.But any either case-I suggest you keep the SCR(static compression ratio)from 9.0 to not much more than 9.3 and cam it accordingly because your trying to move a heavy vehicle.

[85antique]

Thanks but do you have a small block power plant

[85antique]

I would love to put a 454 in it but find a complete motor with all the acc and acc mounts to fit in this chassis is tough big blocks are common but a narrow acc drive isnt

[85antique]

Well i am running low compression the combo
you have listed is above 10:1

[fleamarketer]

Originally Posted by 85antique

Well i am running low compression the combo
you have listed is above 10:1

Nope it is 9.3ish.-18cc pistons .010 down in the hole with 67cc heads.

[fleamarketer]

If you wanted to fab some...........500ci torque monster




Yeah-just kidding.

[85antique]

Finding accessory brackets are hard enough for a 454 !!

[fleamarketer]

I suggest to find brackets for a 454 are easier than you think.Any 454 P30 should swap right in.

[85antique]

Been looking for 3 yrs since scrap went to 20$ a hundred a lot of motors and wheels got scraped heck scrap a car gets you 800+$