LS3 top end swap

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Discussion

mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
Hi everyone,

For those of you not following the HSV Holden UK Facebook page, I thought I'd share my build on here. It's a popular modification over the pond, but only one other person (that I know of) has done it over here- that being GelfVXR.
From what I've read, heads quickly become a bottleneck when tuning- for my intended power goal, upgrading to LS3 heads appears to solve this. So, the power goal.....I want 400rwhp, and 300bhp/tonne. smile
The heads I acquired are from SDPC, from the US. They have been CNC'd, so hopefully should help in my power goals.

SturdyHSV

10,097 posts

167 months

Saturday 8th March 2014
quotequote all
We have the same goals smile

mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
A picture of the heads is here:

mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
SturdyHSV said:
We have the same goals smile
thumbup
You can't beat nice round figures as goals smile

jameshsv

5,844 posts

160 months

Saturday 8th March 2014
quotequote all
mikeyb1987 said:
thumbup
You can't beat nice round figures as goals smile
Nice shiney heads I like very much.How much wer the heads

007 VXR

64,187 posts

187 months

Saturday 8th March 2014
quotequote all
Good luck smile

mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
On top of the above, the other parts ordered were:
-Brian Tooley .0660 dual springs with titanium retainers
-Brian Tooley trunnion upgrade kit
-Brian Tooley lifters
-LS3 injectors (I also bought a set of LS9 injectors, before realising they were sub-optimal, due to spray angle)
-Oil pump: standard GM pump, as there was no need to go aftermarket.
-timing chain: again, standard, as no need to go dual.
-timing cover
-offset intake rockers (due to them being LS3 heads)
-LS3 head gaskets
-other bits and pieces

mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
Unfortunately, the heads were actually L92, not LS3. The key difference being the valves- the LS3 valves are considerably lighter than L92 ones. Therefore, in addition to the above list, I ordered LS3 intake and exhaust valves.

Sorry about all the posts guys the forum software doesn't like long posts from mobile devices!!

jonnM

1,102 posts

139 months

Saturday 8th March 2014
quotequote all
mikeyb1987 said:
thumbup
You can't beat nice round figures as goals smile
You need to get that OCD looked at hehe

mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
jameshsv said:
Nice shiney heads I like very much.How much wer the heads
They were circa £1,400, including the intake.

mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
007 VXR said:
Good luck smile
Cheers thumbup

mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
jonnM said:
You need to get that OCD looked at hehe
I take it you saw the pic on FB last night?! wink

Edited by mikeyb1987 on Saturday 8th March 20:04

jameshsv

5,844 posts

160 months

Saturday 8th March 2014
quotequote all
mikeyb1987 said:
They were circa £1,400, including the intake.
Over all that's a good price for your achievable goal are you not fitting a cam.

SturdyHSV

10,097 posts

167 months

Saturday 8th March 2014
quotequote all
mikeyb1987 said:
thumbup
You can't beat nice round figures as goals smile
Yeah, 500bhp fly seems a good number, and would like weight down to 1600kg for nice 300bhp/ton.

Cam needed for noise though, so round figures may go out the window wink

mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
James has beaten me to my next post- cams!!
I have never vacillated over anything as much as cam choice. At this point, I will state that if you do not have the time (or want to spend the time) looking for a cam, then an off-the-shelf package is probably a good idea for you. I spent 12 months on and off researching US/Aus forums for a cam which would provide be power, but be suitable for a daily driver. Towards the end, after seeing emission results for large-ish cams, I decided on going for a pretty big cam.
So, the spec.....I'm not one to hide specs. It is a 22*/23* 0.610/0.617 with an average LSA. wink

mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
SturdyHSV said:
Yeah, 500bhp fly seems a good number, and would like weight down to 1600kg for nice 300bhp/ton.

Cam needed for noise though, so round figures may go out the window wink
I have to admit to getting a bit giddy about hearing it idle for the first time biggrin

mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
So, being an accountant, I wanted to bring some numbers to the show. To ensure I can reasonably estimate the power increase, I needed a 'before' dyno run, preferably on the dyno it is going to be mapped on. This meant a trip to Doncaster on Friday for a quick power run:

mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
The figures were 322rwhp and 397 at the fly. The torque curve certainly differentiates from the usual euro-box hatches on the roads laugh



mikeyb1987

Original Poster:

2,356 posts

154 months

Saturday 8th March 2014
quotequote all
A few people have said that rolling road under-reads, but it's not an argument I'm going to get into, although I am inclined to agree.
For reference, the car already has headers, sport cats, cat-back and OTR intake. It certainly seems to perform well at Thunder Road and 1/4 miles, and crucially on the road too.
As I mentioned in the above post, the actual figures are nonsense until the car is finished.

jameshsv

5,844 posts

160 months

Saturday 8th March 2014
quotequote all
mikeyb1987 said:
A few people have said that rolling road under-reads, but it's not an argument I'm going to get into, although I am inclined to agree.
For reference, the car already has headers, sport cats, cat-back and OTR intake. It certainly seems to perform well at Thunder Road and 1/4 miles, and crucially on the road too.
As I mentioned in the above post, the actual figures are nonsense until the car is finished.
Will look forward to the final test glad you are fitting a nice cam aswell I hope you get good results already for TR this year.thumbup